ETX-125EC USER FEEDBACK |
This page is for user comments and information specific to the Meade ETX-125EC. Comments on accessories and feedback items appropriate to other ETX models are posted on other pages. If you have any comments, suggestions, questions or answers to questions posed here, e-mail them to me and I'll post them. Please use an appropriate Subject Line on your message. Thanks.
Subject: eyepieces Sent: Monday, February 26, 2001 17:50:37 From: Michael Wong I was wondering if I could ask some advice on my ETX-125. I would like to pick up another couple of eyepieces in addition to my 26mm stock eyepiece and was looking for some advice. I figure I should start with a Barlow, but then what should be the second eyepiece? I was thinking about an 18mm, which would give me 105x and 211x. (My 26mm gives 73x and would give 146x with a Barlow.) What do you think about the eyepieces from the Surplus Shed? I was thinking about those as well... I've been basically looking at the moon and Jupiter and Saturn and haven't yet attempted a polar alignment or serious hunt for Messier objects yet because a tree line obscures Polaris from my backyard. I'll have to travel to find some good sky. Hoep to hear from you. cheers, m "No! Try not. Do, or do not." -- YodaMike here: Certainly a 2X Barlow (the Meade #126 works great) is a good choice. And your eyepiece selection is OK for starters. Eventually you'll likely expand in both directions; longer and shorter focal lengths. I've not dealt with that dealer.
Subject: saturn Sent: Sunday, February 25, 2001 15:30:50 From: saber@dircon.co.uk (Sam) Tonight probably had the best seeing conditions since I bought my 125 and the conditions brought improved clarity and an abundance of moons round saturn. For the first time I started to get a glimpse of the cassini division though it was like the thinnest of hairlines. An odd thing though, the portion of the ring nearest to us had an odd black line cutting right through the width of the bottom right side of the ring as it comes round in front of the planets disc. I'm not reffering to the dark spokes often written about. If you can imagine the disc of saturn at around 5 o'clock on the disc i.e. South South East, as the ring comes round and eclipses that section of the disc there was a curved black line which ran along the outline of the eclipsed part of the disc. I assume its a shadow fro the ring but I can't quite understand how I would see it when it should have been obscured by the ring itself. There is probably a simple explanation, though I'm not sure if I been quite clear enough in my explanation. I would be interested in your comments. On Jupiter I was able to see 2 orange coloured bands across its diameter though I could see no more than that, no cloud swirls, festoons etc. etc. as all the Meade leaflets would have you believe can be seen with the 125. Having said all of the above, I've still not used my 125 on a tripod, so I guess I've got that to look forward to. I hope to put that to the test in a few days. I tried my hand at some photgraphy of the planets (in the early evening, the crescent moon, venus, jupiter and saturn were all easily visible) with my canon eos 300 with a 300mm lens on a manfrotto tripod. Its my first attempt and I will send the pics if any of them come out. I gave a friend his 1st sight of saturn on friday night, it blew him away!! as it it did me, the 1st time I saw it. Regards, SamMike here: You are likely seeing just a darker portion of the inner ring. Note that you can see the planet's shadow on the rings that go behind the planet.
And:
From: sherrodc@ipa.net (Clay Sherrod) The sky is just now getting dark here, looking at the same stars you were peering at about six hours before! Odd feeling.... Your phenomenon on Saturn is probably what you supposed: the shadow cast by the ball or globe of the planet onto the reflective rings. It affords a very good 3-dimensional aspect of the planet that you otherwise might not have! On Jupiter, you CAN see some of the detail you were describing, but you must have a perfect night and a steady telescope; when you begin using your heavy duty tripod, you'll be amazed at how much easier it is to concentrate on the fine detail....it is there right now, you're just missing it. Sounds like you had a good night....now I'm about to go out, align and get started on some serious observing! Be sure and contact your friends in Miami! good skies! CLAY
Subject: ETX-125 EC Woes.... Sent: Sunday, February 25, 2001 13:16:18 From: jjgemmill@home.net (John Gemmill) I bought my ETX-125EC in November, '00, the same weekend the Celestron guys were visiting OPT and demonstrated the NexStar 5. When I first configured my ETX and started using it, the declination drive exhibited skipping problems. Once or (maybe) twice a night it would skip, as though the OTA had bumped into something. Most likely the problem was the worm gear assembly not being well positioned, but I didn't know about Meade's QC problems nor the ETX tune-up back then and thought it was just the tightness of a new system. At first I only had the simple controller that comes with the scope and thought the Autostar would exhibit better behavior. When I got the Autostar, things seemed to work fine - well, as fine as, if not more so than any ETX works out-of-the-box. I only ever had one creep-after-beep experience, later on, and two mysterious Autostar lockups requiring a reset, and for a long time I thought only other people were having all ETX problems I was reading about. In polar mode on the JMI Megapod - a must-have for any ETX owner - the system tracked for hours and the Celestron Vibration Suppression Pads - another must-have for anyone with a scope - made the system rock steady, especially on my wobbly third floor apartment porches. But the dec skipping problem was slowly getting worse and worse, eventually causing me to have to reset and realign several times a night as the Autostar would report a drive problem and quit working. Just before Christmas, the Autostar gave up on the dec drive altogether, despite repeated Reset/Calibrate/Train cycles. The simple controller would still operate the drive just fine, with similar occasional skipping on the dec drive, so I knew the motor itself was still working. I had planned to purchase a Pelican case and take my new scope home on the airlines for Christmas, but without the Autostar there really wasn't much point - I couldn't find a checkable case for the Megapod and in Alt/Az mode w/out the Autostar well, not very satisfying when taken in consideration of potential travel effects on the optics. I should have taken the scope back to OPT, who would have handed me a replacement on the spot, but I had read about people getting unit after unit, sometimes without ever getting satisfaction. And my ETX's optics were awesome!! So I called Meade and arranged for them to service the scope. After the Hollydays, I packed the scope up and took it up to Meade myself. Their parking lot was completely full and there were even cars parked out on the street (you can see their facilities in the photos on their website and catalog), so I ended up parking my motorcycle on the sidewalk in front of their door. The suit-and-tie representative (I could name names) came to the lobby to meet me and accept my boxed scope, but somehow my unit didn't enter their computer system for another week after I dropped it off. ??? I called every week to check on the status and after three weeks the OPT guys said that if I hadn't heard anything by the next day, they would start calling. I never heard whether they actually called or not, but my scope finally showed up at the end of that week (four weeks total), just one weekend before I was to leave for a two week business trip - another two weeks w/out my scope!! When I opened up the scope, I happened to notice there was a small ring of cardboard down in the OTA, sitting on the once beautiful primary mirror. That wasn't right, so I looked closer and saw little pieces of cardboard dust on the mirror, as well. Dang!! I called the OPT guys right away (it was just closing time) and they said to carefully repack the scope such that the cardboard was not resting on the mirror, and return it there in the morning. I tipped the scope so the cardboard was not on the mirror and started repacking. I had to tip the scope face down to get it back in the outer box and it was at that point I heard a horrible clunking noise from within the system. Huh?? I opened it back up and discovered the source of the clunking noise was the primary mirror coming loose from its mounting - horrors!! The next day at OPT, I was scared to look inside the OTA, more so after they looked in and said there were glass chips all over the place. I braved a look: the baffling on the inside of the OTA was dinged and scored - ruined - and the primary mirror was trashed. Apparently the mechanism that retains the mirror on its little tube mount had either failed or been improperly reassembled. BTW, it was obvious Meade had opened up the OTA: the holes in the retaining ring around the front lens where the tool is used to unscrew it showed serious signs of wear that had not been there a month before. Well, the night before when it had become obvious I was going to get a new scope in any case, I started researching the LX90. As the OPT guys were standing around with their mouths on the floor at the horror in my ETX OTA, I suggested perhaps I should upgrade. For about $400 more than the ETX-125 with an Autostar and JMI Megapod, the LX90 comes with an Autostar (494) and heavy tripod (same as LX-200), plus double the light gathering capacity (same optics as the other Meade 8 scopes, 2000mm f/10). For me, the main drawback is that it's probably not going to be motorcycle-portable - it took two trips to OPT to port the LX90 boxes on my bike. I think I can live with that, especially now that I've actually seen Jupiter through the LX90!! The bottom line is: if you're serious about an ETX-125EC with GoTo and a stable tripod, the LX90 is worth a hard look and the wait to save the 30% more required to buy it. And if you're still serious about the ETX, consider buying the field scope version and an Orion/Vixen Great Polaris equatorial mount (total cost similar to the LX90). -=> JJG <=- __________________________________________ John Gemmill jgemmill@jps.net
Subject: Hello!
Sent: Saturday, February 24, 2001 18:03:58
From: sherrodc@ipa.net (Clay Sherrod)
John - great to hear from you!
Sorry about the luck with the ETX 125; mine, two gave me problems but I
licked 'em. I wasn't going to give up on it, as it was my retirement
present and a sense of pride. Now I would not part with it for the
world. It is REALLY tight and performs optimally.
I am glad you moved up to the LX 90; I have a couple of friends who also
have them and they love them. I really like the features and firmness
of that scope over the LX200, and most definitely like the AutoStar
methodology over the LX 200 command center. Obviously, with your
results so far you can see why!
Good luck with the astrophotography; Rick Krejic's photographs with an
ETX 90 should be an inspiration to us all! I do like piggyback and
particularly when there is a nice bright comet out there....
Keep in touch and best of luck to your new scope and CCD when you get
it! And, above all - THANK YOU for the kind comments. There are some
great people who enjoy helping other amateur astronomers from Mike
Weasner's site, including of course Mike himself and the infamous Dick
Seymour (our computer and electronic guru of sorts!). Together, we
usually have been able to figure out the darndest things!
We look forward to seeing some great photos and a full report on the LX
90!
Clay Sherrod
-----Original Message-----
From: John
I've been an enthusiastic follower of your abundant contributions to
Weasners Mighty ETX site for the last few months now. Wow! You
must have a bunch of free time to keep such a prolific flow going!
Maybe in another 20 years or so gads I'll get out from under my
work-a-day and join you. ;-)
I purchased an ETX-125 at OPT in November when the Celestron folks
were there (and met Mike a week later when the Meade guy was there).
The optics in the ETX are superb and with the MegaPod in polar mode
I was glued nightly to my 9.7 mm Super Plossl with Jupiter and its
moons rotating around in my sights. But Meade's QC problems with the
ETX drive system (my dec drive eventually crapped out completely as
far as the Autostar was concerned, even though the hand controller
could still drive it okay) eventually caused me to upgrade to an
LX-90 which I should have purchased first, anyway!
I've had the LX for about a month now, but the weather here in
Southern California and a long work-related trip back east have
conspired to prevent me from having good seeing nights to play.
Still, I've seen bands and swirls on Jupiter (similar to but better
than the ETX, as expected), Saturns moons (never did see them with
the ETX), plenty of nebulosity, and more galaxies than Id really
been aware were available for amateurs to see. The 494 Autostar has
performed admirably (unlike its 495 cousin), giving me flawlessly
accurate GoTo ability for everything Ive thought to point it towards
(except satellites oh, well). Just last night (after the clouds
broke) I set up and viewed for 4 hours or so (not great seeing),
left the LX tracking Sirius, slept for 4 hours, woke and did a GoTo
to M-86: it was dead center in the 26mm (Sirius had gone 10 degrees
below the horizon). I borrowed a laptop computer for a weekend and
used TheSky to drive the scope with even more satisfying results.
I'm in the process now of purchasing a laptop (toting my super tower
and 21 monitor out on the back porch for viewing is, well, not an
option) and plan to get into CCD astrophotography in the next view
months. Rick Krejcis LX-90 pic of Jupiter in Mikes Guest Planetary
Astrophotography section is making me drool! I'll get a piggyback
adapter as well, and one of my first planned wide field shots is
going to be the Pleiades planned even before I read your excellent
Observing the Pleiades article!
Thanks again, and keep em comin!!
Clear skies,
-=> JJG <=-
John
Oceanside, CA
Subject: Resolving Double Star Sirus A/B Sent: Friday, February 23, 2001 20:34:56 From: radugas@mindspring.com (DjP) I am an eager but very new amateur astronomer and have taken to pointing my ETX-125 to the suburban skies of south Florida in the hopes of resolving double stars. After consulting my recently purchased Cambridge Star Atlas I have enjoyed the doubles that makeup the constellation Orion. I then attempted to resolve the double star Sirius. The above mentioned atlas lists the magnitudes of Sirius A and B as -1.5 and 8.5 respectively, however I have seen Sirius B listed as dim as 9.3 in other publications which state that a 10 inch aperture is required to resolve this beautiful example of a binary system. I believe that I can see this partner with my 5 inch optics, is this possible, or am I simply seeing a dim star that is close to this bright gem in the night? Wishing all clear, dark skies D Palliser Fort Lauderdale, FloridaMike here: The separation is about 4.6" and the theoretical resolving power of the ETX-125EC is 0.9" but I would think the brightness of A would overwhelm B under most visual observing conditions. But perhaps not. I'll have to try on my next night out.
Subject: Re: AutoStar and your ETX 125 Sent: Friday, February 23, 2001 08:52:34 From: DonMcClelland@webtv.net (Donald McClelland) Hi Clay, I want to start this message by saying you guys are fantastic (you, Richard and Mike) with the help you bring to the site. You with your astronomical and technical expertise, Dick with his extensive technical advise and Mike's all around knowledge he's gained from the site. My sincere thanks to all of you! In answer to your questions... 1) It was the 90EC which I still do own, I love it but financial practicality tells me I should sell it. 2) Firmware is 2.1EK installed by Meade in December. 3) I didn't try the hand controller but I did try this. I tested it on terrestrial landmarks and it found each one almost perfectly, some were dead center others were only an arc minute or two away ( I could have bumped the scope on the table) and there were no random slews or significant pointing problems so it's probably not a wiring issue. 4) The only problem I had with the previous scope was some mild (rubberbanding) which wasn't too inconvenient. I just overcompensated and let it slew back to center. I do have a theory though. When I first bought my ETX 90EC I had similar but not as dramatic problems. Meade customer service told me that some telescopes need a break in period e.g. grease that needs to be distributed in the gears. Eventually the scope pointed very well (one star alignment) however I only have about 50 degrees view from my balcony. I do remember taking the scope in to Meade but I don't remember if it was a random slew problem. Interestingly the 125 seems to be working better now since my message to Mike the random slews are smaller only about 4-5 degrees. At least it's not straight up like before. I'm trying to (exercise) the declination to see if there might be improvement in the gears. Who knows it might work but that doesn't explain why it works so well on terrestrial objects. Hope this message wasn't too long. Thanks again, DonAnd some thoughts on grease distribution:
From: sherrodc@ipa.net (Clay Sherrod) The idea of grease distribution is a good one and I have used it myself. Try the following (as you indicated your scope seems to be getting better, this may signal we're on the right track): 1) Unclamp the RA (azimuth) completely and rotate the scope in that axis in both directions all the way around to the stops; repeat three times; 2) Now, firm down the clamp slightly but enough to offer some resistance; DO NOT overtighten, the scope should move tight but freely; 3) Repeat step one. 4) Now, unclamp the RA completely (you do not want the azimuth moving in this step) and initialize your AutoStar to engage the slewing motors; set your speed on "6" and press either button in Azimuth for 2 minutes continuously; stop after 2 minutes and press the OPPOSITE button; 5) After that, clamp firmly so that your azimuth drive now engages at speed "6"; place the telescope in "home position" and at that speed, slew it 90 degrees in either direction; leave clamped and slew 180 degrees to point opposite. 6) Unclamp the RA clamp and manually turn telescope back and forth, ending up at home position again, and clamp firmly; 7) Set your slew speed to "9" and slew you azimuth in both directions in short bursts for several dead runs.... This does two things: it "sets" the clutch to engage by "marrying" the driver gear to the clutch locking plate; in addition, it distributes the lubricants that you were mentioning very evenly. Also, if there is any excess lubricant interfering with the clutch's ability to clamp, this may work it out of the system without you having to get into the guts. Also - and IMPORTANT - put the AutoStar BACK onto your ETX 90 EC and see if you are having similar problems now with that scope. It is possible that some recognition configuration maybe as gone awry after taking it off that scope; if the -90 moves erratically, then it is in the AutoStar. Good luck...let us know. AND THANKS for the nice comments. Clay Sherrod
Subject: Focal Reducer for 125EC Sent: Tuesday, February 20, 2001 16:32:59 From: alkam@megsinet.net (Al Kaminski) Is a focal reducer a workable and useful accessory for the 125EC? I realize that is a loaded question. Useful is in the eye of the beholder, to paraphrase. What I'm really asking is if a focal reducer actually can make viewing more enjoyable. Or does it have limited usefulness because of the room it would occupy at the rear of the scope.Mike here: I've used one on the ETX-90RA and ETX-125EC and it works. But as you say, what works for me might not work for you. Yes, in some orientations it can interfere with movement of the scope when mounted at the rear port. And depending upon the eyepiece you use, the image quality may be slightly but noticeably reduced.
Subject: Image Shift Sent: Tuesday, February 20, 2001 09:37:44 From: wolfsb@qwest.net (Wolfgang Siebinger) I had the opportunity to buy a ETX-125EC "Outfit" (Autostar, El. focuser, Tripod) for a really good price from a friend who never used it. But before I jumped into the deal I really searched your web site and the information was overwhelming. This 125EC shows some of the flaws which are described in different postings, but there is one which bothers me and I didn"t find information about: when I center an object - lets say Jupiter - and refocus the image nearly slips out of FOV. This happens in either direction of focus. Is this something I can fix myself with reasonably mechanical skills? I really enjoy your web site as newcomer to astronomy. Wolfgang SiebingerMike here: If you search for "image shift" you'll find several references to it on the ETX-125EC Feedback pages. The ETX-125EC you purchased must have been one of the early models. Meade fixed the problem rather rapidly. Contact them. Explain the situation as it is likely out of warranty.
Subject: pier at 5 degrees North Sent: Saturday, February 17, 2001 05:58:01 From: sherrodc@ipa.net (Clay Sherrod) To: bernard.fournier12@wanadoo.fr I am glad you finished your pier and would like very much to see what you have done. I very much enjoy mine. I thought I had a problem with lower-than-usual latitudes here in Arkansas, but "5 degrees North!" I really envy you, the best of both worlds, but not quite "down under" yet. As long as your pier is firmly supported on the SOUTH side (I would even consider anchoring it with a bracket if you have it permanently located, or even a heavy stone or brick), there should be little wear and tear on the telescope itself. Inside the drive base of the ETX 125 there is a very large and heavy axle assembly made out of steel and supported by an oversized bearing which supports the 17-pound load of the telescope. Tilting it in such a way will most definitely not hurt the drive nor scope. Since most of the weight is in the scope base, then the fork arms and OTA should not be a concern either. Actually, I believe that the extreme tilt of your telescope will greatly IMPROVE tracking, allowing for both the DEC and RA axes to be "loaded" against the driving mechanisms and thereby decreasing backlash and gear train "play." My thoughts would be focused on the pier itself and how I could make it very supportive against the torque of the telescope suspended such as it is. I believe that if you anchor the pier, you will not have ANY problems whatsoever; if you choose to leave your pier outdoors (which I do, covered with a tarp when not in use and bring the scope indoors), consider FILLING IT WITH SAND to increase the mass and greatly dampen the vibrations. You will be amazed at the difference the added mass makes! Good luck, and send photos! P. Clay Sherrod Arkansas Sky Observatory
Subject: Re: ETX125 Stability Sent: Saturday, February 17, 2001 04:29:53 From: sherrodc@ipa.net (Clay Sherrod) To: Doug Yes, the tape binds up the pivot on the undriven end, but you are right, it allows the inner bearing to do the rotation. After the tape seats itself, it does work very well, and yes always use the white Teflon tape. I am glad the tape has taken out the DEc slop in that point of contact; it worked really well for me. I am sure that, in time, it will be necessary to replace the tape as it compresses more and more, but -hey -it's a great fix! You are correct about the molybednum SO2 as a dry lubricant. We have used it at the observatory for very small precision (very tight) gearworks and moving smooth surfaces that make contact. HOWEVER!! Removing all the grease from the gear teeth (the thick, gooey elastic type grease) actually INCREASES slop in the Meade telescopes. The grease makes a sort-of semi-liquid bushing that actually results in better tooth-to-tooth engagement throughout the gear train. I only remove grease from contact surfaces that should not slide, like clutches, lock-downs, clamps and pressure plates. Gear I always thoroughly clean with Mineral spirits and THEN recoat with a toothpick only the GEAR TEETH with lithium grease (white) as this grease in NOT temperature sensitive and holds up in both very hot and very cold conditions. I would really advise against running "dry gears" as you will see an actual significant INCREASE in gear-to-gear slop. Let me know how it progresses! Thanks for the info....sounds like one-half of your project is underway! Clay Sherrod -----Original Message----- >Clay, >Real quick note here. > >Your technique with the Teflon tape is one I thought of a while back but >I couldn't seem to make it work because it was to tight. I think I was >using the 'gas pipe' yellow Teflon tape at the time and it may be a mil >or so thicker. Anyway I tried it again on the un-driven trunion with >only one wrap. Here's where I made an interesting discovery. With too >much tape on the trunion the "purple' bearing won't rotate on the shaft >BUT rotates in the yoke just fine with close tolerances. I added some >Aladdin Magic Lube (plumbing lub and sealant) and the bearing is a smooth >as silk with no slop. As the bearing materials are the same, I think >I'll leave it for now. > >Buy the way , the Aladdin Magic Lube comes in a small blue plastic can >and is used to lube PVC parts and 'O' rings in swimming pool valves. It >seems to work better than anything that I've tried to date and doesn't >migrate. I wouldn't recommend it for metallic surfaces only plastics. > >On the way to work this morning I remembered what we used at Hughes to >lube sector gears for the syncro encoder transmitters in large earth >stations. It was a dry lube called molybednum disulfide ( I think). It >looked like graphite when it dried and could be baked on gears at about >450F to set. I wonder if this would be a viable replacement for the worm >& sector gears. At least there wouldn't be a problem with migrating >grease. I'm going to see if I can find a spray can of the stuff and try >it. I have a VB brogan that will energize the RA and/or DEC axis for an >extended period of time to check for ware. > >DougAnd more:
From: edutton@infi.net (Ells Dutton) The brace is a piece of clear acrylic from the local plastics shop cut top shape on my table saw. That arm is STIFF. There is a lot of torque stress there in the polar mode and virtually none in Alt/Azi, probably why Meade thought they could get away with it. (also lots of stress there when it crashes on the ground.) I noted you referred to this brace in a response to a Doug on METXS (the Mighty ETX Site). You also mentioned the rubber feet. Have you noted that they are note even mounted on the base's hardpoints, they are like little spring boards and it is not just the rubber flexing.. There are three convenient threaded holes next to those feet that I have inserted three bolts that stick out just a fuzz further than the feet. They to make a big difference in stability in either the Alt/Azi mode with the unit setting on a flat surface or in the polar mode when bolted to a flat surface such as on yours or my piers. It sounds like you just removed the feet, which would also address the problem. Been a little cloudy and or hazy here, so not much viewing for a few days. Time to catch up on just reading your latest contributions at METXS. Thanks. Can't wait to try the observing tip on the "floaters". Darn, those things are annoying. First time I've seen mention of them in astronomical viewing tips. Great job - again and again and... Ells
And some more info on this brace:
From: edutton@infi.net (Ells Dutton) The replacement feet help a little, but nowhere as much as the acrylic brace in polar mode, just make sure that the brace is put on the left arm (for other readers). I'm working on an idea for the other side that will allow the dec. motor access. Kind of fun to be out of warranty. For the feet I used round-headed slotted bolts with a thin nut thread all the way up to the head so that you can tighten them down and never think about them again. Also covered the bolt heads with a couple layers of duct tape - sexy huh! Be aware of setting the modfied scope on a hard surface, it goes clunk. Will still scratch (dent) the furniture so I use an old Orion Tele catalog to set it on. Oops, I do like Orion catalog service but have a lot of those catalogs. May all you skies be clear and steady, and may your telescope go where it is told. Cheers, EllsAnd:
Ells - thanks for writing. GREAT tip on the feet for the ETX as a replacement for the rubber knobs. That is a super idea; felt pads on the feet would preserve any finish and still give maximum stability; I am glad you clarified on the brace - it looks metal in the photo, but what works works. You are right..Meade I am sure anticipated the yeoman's share of observers to be setting up in Alt-Az mode so the stress points did not matter; all torque would be nestled against the center axle. See you - Clay SherrodAnd:
From: sherrodc@ipa.net (Clay Sherrod) Ells - nothing quite like a little duct tape to get the old Meade telescope up to par. I believe that a thick metal brace inside the non-driven arm and perhaps one on out-fo-the-way in the drive arm (there is a place) might help stabilize the flexure as well, but not as much as that huge acrylic piece you have. The bolts are a really good idea; I wonder if a very thin piece of rubber, like inner tube rubber, would help prevent slippage yet not cause movement like the old pads.(?) Where would our scopes be without Duct tape....mine has some inside the DEC setting circle to prevent misalignment! Clay
Subject: Polar set up at low latitudes Sent: Friday, February 16, 2001 14:32:30 From: bernard.fournier12@wanadoo.fr (Bernard Fournier) Just finish my new pier (really inspired from Clay's one) to set my Etx 125 in polar mode. Wondering if my very low living and observing latitude (5 north) could be an inconvenient because the scope, in the home position, has a very strange attitude (tube and forks aligned and horizontal) so the mass/load repartition doesn't look very good. I am afraid it could stress some of the mechanics not on the pier whitch is very rigid and well balanced but inside the scope itself. I am trying this new set up in order to get free from the so called "rubber band effect" which is very annoying in AltAz when trying to do some ccd imaging. (Mike I send a picture of the moon attached to a separate mail) Hope to have some comments about this. Amicalement Bernard Fournier N 5 09 / W 52 39 bernard.fournier12@wanadoo.frMike here: Well, certainly when mounted equatorially the telescope hangs at an angle, which is sometimes extreme as in your case. And I suppose it is possible that the base will flex since there are only two attach points. But I would hope that there is no damage that could occur.
Subject: Re: ETX125 Stability Sent: Friday, February 16, 2001 12:51:22 From: sherrodc@ipa.net (Clay Sherrod) To: Doug Concerning your clutch-fix for the ETX 125; I had a major modification I wanted to do, but was having difficulty getting the clutch plate away from the RA clamp bolt. Anyway....I finally did, got the clutch changed out and all is up and running like clockwork....so disregard the message, and thanks anyway! Glad you wrote; it sounds like you are experiencing most of the problems that those of us who really want to take our telescopes seriously go through. I totally agree that the weak place on the entire telescope (although the scope needed to be tweaked from top to bottom when I got it) is indeed the fork mounting arms and the mechanisms that 1) allow the telescope to move within the arms; and, 2) the backlash and slop when slewing in dec./Alt., which is particularly troublesome if you are mounted in Alt-Az mode and require the motion of BOTH AXES to maintain sidereal tracking. 1) trunion problems: As you know, there are many complex problems in the overall design of the fork tines of the ETX; in the ETX 90 the problems are not so noticeable, but are still there; the -125's mass magnifies the problems many-fold. You have mentioned two problem areas, yet there are actually three: a) the trunion into the fork arm "bearing;" as you know, Meade has decided to do away with the small nylon bearing that used to work between the hole in the fork arms and the trunion that passed through it. Notice that the trunion is TAPERED toward the OUTSIDE of the optical tube assembly, allowing a tighter fit; yes, this is a good idea, but Meade stopped when they should have kept going here. This meshing between the fork arm "receiver" and the trunion has lots of play in it; without the OTA attached, it is easy to miss, but with the tube assembled, you can see it rock. I have done two things to alleviate this rocking motion at this junction: (1) I have wrapped each trunion with two layers (very tightly wound) of Teflon white tape and rubbed the tape hard against the surface to create a "bushing" of sorts. This is not good if you do not lubricate well with Lithium grease INSIDE the fork hole and the tape-covered trunion itself. When first re-inserting the tube assembly arm into the fork arm, the assembly seems way too stiff....however, work it back and forth and it quickly looses up and moves very freely, but without the slop. Experiment with the number of wraps around the trunion; each side is different. The second fix I did in this area was to insert two very small FIBER (not metal) washers between the exposed end (that with the threaded hole - has a brass insert) of the trunion and the INSIDE of the setting circle; this allowed more surface-to-surface contact and still maintained a free-wheeling surface for movement. While on the rocking of the trunion, let me tell you about PROBLEM #3 that most people don't even notice, yet is a factor in nearly 1/2 degree of play in the ETX 125; my ETX 90 does not - because of the smaller mass - have this problem! With the OTA in place, gently rock the scope in the locked (DEC) position and look at the FRONT of the arms supporting the optical tube (one on each side, these are the ones with the two holes in the rear to attach the tube assembly). Note that the scope is securely tightly at the rear with the two small allen screws....but NOTHING at the front; the scope flexes here since only surface-to-surface contact (no lock-down) holds the front in place! Big problem.... You can fix this easily without destroying the tube or mount. Take off the OTA and each of the two OTA support arms; get some rubber cement and a rubber repair kit for a bicycle tire inner tube (it comes with the cement at Wal Mart for .74 cents) Cut the rubber material to fit exactly the inside shape of the front end of the OTA support arms and glue to the inside so that it will rest against the OTA when you put it back in place. Like a rubber cushion, this "gasket" holds the heavy front of the ETX 125 in place firmly!! 2) Flex in the fork arm itself - Yep, this is a big problem with the ETX 125; Meade should have put a rib in the molded plastic; there is room for one! We have one ETx user who, because of a breakage on his -125, epoxied a metal plate (bent into an "L" to conform to the fork where it meets the base turntable). Not only did this "fix" put his scope back together, it actually made it so strong that vibrations hardly exist! Now, if a person wanted to TRY something like this, you could go to Lowes or Home Depot and buy the flat L-bent "mending brackets" to do the same thing; indeed, it is possible, if you look inside the plastic plate that covers the drive mechanism (and the "nothing" on the other side) you will see that if you you so desired, you could drill through the fork arm for, say #12 bolts, and attach such a bracket from the inside (using Fender washers for support and lock washers to prevent cracking), with the horizontal part of the plate extruding onto the turntable toward the RA clamp! A small slot cut into the plastic inner fork cover would allow you to re-attach the cover for safety and looks. This last suggestion may sound extreme, but if you put the pencil to it - and I have - it is a very workable and beneficial adaptation to an otherwise rocky problem. Another solution, knowing that the flex is coming from the worm gear plate "bending" the plastic of the fork arm is to shim BEHIND the worm gear plate (between it and the outer fork arm plastic) with as large an AREA (not thickness, although the thicker the better) plate as possible without interfering with the drive mechanism and encorder wires. This, too, if you look, can be done....there is room. I would love to exchange ideas with you after your receive this message and find out what direction you are headed; my scope is a killer and can pull a truck without slop, but only because I work on it constantly. I pity the poor soul who does not have the know-how nor the time to do all this! I have appreciated your comments on the drive clutch and look forward to hearing from you soon! Good skies, and steady scopes... P. Clay Sherrod -----Original Message----- >Clay, > >I read your review on the ETX site and tend to agree with you. Good optics >and marginal mechanics. I've had the scope for a few months now and >discovered that I needed to build my own pedestal (Its on the site too). >Once I have the polar mode aligned correctly most things appear where they >should be. My biggest complaint is the excessive 'flex' or lack of >compliance in the DEC axis. In most cases it isn't too much of an effect >but it takes the 'shine' off the device as a precision instrument. I >figure there are two ways to fix the flex issue. Buy something else or >fix it. I seem to be opting for the latter because of my engineering >background. > >I believe I have found some points of flex and would like your opinion if >you have time. > >1. The trunions pull away from the OTA when the OTA is moved. This tends to >cause alignment shifts when the eye piece is replaced with my CCD camera. >2. Some of the trunion side play is caused by the sector driven gear >riding up on the worm causing a slight sideways movement. This is a result >or the yoke flexing. > >I've been toying with adding some Aluminum plates to reinforce the yoke and >some form of clamp to secure the flex in the two OTA trunions. Do you have >any ideas along these lines. > >You seem to be into the ETX125 so I hope you won't mind discussing some >ideas from time to time. One of my other projects is building a Peltier >cooled BW Quickcam capable of long exposure times. A bit of overkill but >fun. I own a SACVb camera and found it to be a re-packaged 3COM web camera, >but live and learn. > >Doug
Subject: Re: sidereal tracking
Sent: Thursday, February 15, 2001 13:46:03
From: sherrodc@ipa.net (Clay Sherrod)
To: Paul
Absolutely. It will track very well at sidereal rate in either Alt-Az or
POlar mode; since you are getting the JMI tripod, I think you will want
to try polar as I have found it to be more reliable, accurate and much
smoother with less vibration. (two motors are required for sidereal
motion in Alt-Az and only one for polar).
Get in touch if you have more questions....great choice, by the way!
Clay Sherrod
-----Original Message-----
From: Paul
First, I would like to thank you and Mike for all the valuable
information you provide, without it I would not be brave enough to
jump back into the game. After many months of research and hours
pouring over Mike's site I have decided on a 125 and a JMI
tripod-wedge combination. One question if you please, Meade's site
mentions that the scope tracks at 8 and 32 times sidereal as well
0.75 and 5 degrees per minute. I assume it also tracks at sidereal
rate as well. Am I correct?
Thank you!
Paul V
Subject: Re: ETX 125 astrophotography
Sent: Thursday, February 15, 2001 13:43:51
From: sherrodc@ipa.net (Clay Sherrod)
To: gaudetr@nbnet.nb.ca (Rob Gaudet)
Regarding astrophotography with the ETX 125, I am presently using mine
only for some prime focus shots of the moon and planets PLUS a lot of
piggyback using a 300mm telephoto; I have other telescopes that I
dedicate to photography and have the -125 as my portable scope. The ETX
125 is not the best selection for astrophotography for the following
reasons:
1) the f/15 focal ratio makes it much too slow for deep sky and wide
field work, requiring very long exposures, even with CCD capability,
which brings up,
2) there are no longer any back-end adapters that allow either eyepiece
projection photography (for hig power planet work, nor for attaching a
CCD camera or off-axis guider, CCD autotracker. Thus, there is no
guiding provision allowed;
3) the ETX series uses the Autostar which is NOT a drive corrector and
thus is much more difficult for long-term guiding during deep sky
photography.
For astrophotography I would suggest the LX 300 f/6.3 8" or 10" scopes;
you will gain nothing (because of the same mechanical (i.e., manual
guiding with Autostar) restrictions with getting the LX90 8"; also the
LX 200 8" and 10" f/10 scopes are getting in the "too long focal length
range" as well.
What I would do if I were you is to focus in on EXACTLY what your top
three primary uses of your telescope will be and get back to me....I can
sort through that and come up with some recommendations. Right now, if
astrophotography is #1 or #2 and not just just a curiosity, then the ETX
will not really be suitable; if you want the best portable visual scope
available, then it is my first choice!
Make your priority list and get back ASAP!
Happy to help -
Clay Sherrod
Arkansas Sky Observatory
-----Original Message-----
From: Rob Gaudet
Have you done any photography with the 125, if so, how do they look?
This was going to be an avenue that I was going to explore also with
a telescope....many other users suggest the lx200 for this and I can
see why.
Rob Gaudet.
gaudetr@nbnet.nb.ca
Mike here: There are some ETX-125EC astrophotography examples on the site.
And more:
From: sherrodc@ipa.net (Clay Sherrod)
To: gaudetr@nbnet.nb.ca (Rob Gaudet)
Well, the ETX-125 has "gotcha" on two out of three; for ease of setup
and observing pleasure, you're not going to beat the ETX 125; I just
did a little work (adjusting the clutch for my touch) last night and
boy, am I glad I ever got it. There was a time (by the way it was given
to me as a retirement present!) when I was going to trade up to an 8",
but did a little comparative shopping and decided otherwise. Glad I
did.
Astrophotography is fun and can be very exciting and if I hadn't already
done so much of it, I probably would have opted for something more
suitable, probably the LX200 10"; the biggest difference, visually is
in set-up and easy of operation. I can be on my 30th object (I do a lot
of variable star estimates) while others are still running the extension
cords.
If money is a consideration and you still want that extra aperture, the
LX 90 is really a nice "go-between" and a very good scope for the money.
It does have some astrophotography drawbacks as far as tracking
capability, though.
Anyway...we'll be here to help, so don't hestitate to ask. Two out of three.....
Good skies, and good luck on your choice. Clay Sherrod
-----Original Message-----
From: Rob Gaudet
Top three primary uses are 1 being the most important and three
being the most unimportant.
1) Observing
2) Astro photography
3) Ease of setup
I think the 8 inch Lx200 is going to be the winner..... but I was
thinking that budget wise...the ETX125-EC is the better buy.
Rob Gaudet.
gaudetr@nbnet.nb.ca
Subject: Re: etx125 Sent: Wednesday, February 14, 2001 15:57:45 From: sherrodc@ipa.net (Clay Sherrod) To: Tommy Norton Glad you have gotten the ETX 125 and sorry you have had some snafus with it. Mine, too, came with many small problems (i.e., clamps that would not engage, some slop in dec., etc.) as well. That is what initially put me onto Mike W's ETX web site and I've been happy ever since. Let me tell you that just the opposite of what you fear is probably true, and I'll help you any way I can to get to this point: so many of the ETX 125's arrive into the hands of eager enthusiasts who quickly learn that there are small idiosyncracies that must be dealt with before the scope can operate satisfactorilcy. It is a shame - as you said -to have a thousand $$ instrument that has to be fixed as soon as you get it. Nonetheless, quality control is the problem: the scope is not. Overall, you have what I believe to be the finest portable scope on the market, bar none. The problems that you have encountered, if you have not already done so, are probably the same ones that others have run into, and hence are subjects throughout the ETX web site. There is a wonderful section on ETX Tune Up, by Jason at Scopetronix that teaches you some very fundamental things about the way the mechanics work in your scope. Between other users who will be happy to assist and that (and other "fix up tips in the same section) you will have your scope in tip-top shape. Here is the "opposite part." Once done (like I say, it seems to be opposite the way manufacturer-consumer relations should be), you will NOT have to worry about the scope again. Actually, mine was sort of a blessing in disguise, as it taught me more about the workings of my scope for the future. the optics have NEVER had any problem and are the best I have seen,as are all the others I have tested. Once tweaked, the drive system and computer operation is exception and far better than the competition. Hang in there and we'll get you going the way you should. The scope is your "hobby," only you have extended your interest maybe into areas you did not think you had to. I have been into astronomy for well over 35 years (30 years professionally) and have NEVER seen a telescope - pro or amateur - that DID NOT have to have something done to it as soon as it is out of the box. The "nature of the beast" of amateur astronomy as they say. Just remember that, yes you WILL be happy with the scope and actually you might have a little fun fixing the small "bugs" just the way you like it. My biggest problem was understanding all the automation and computer-eze. I'm from the old school with lots of computer knowledge, but my gosh what a wonderful system in such a tiny package. I have REALLY had to ask for help over and over again all through this learning process. I think the "user" in my case is a bigger problem than the minor irritations that arrived with the scope. hang in there.....we'll help you! In the meantime, look through the TECh TIPS and "New User" section for tips on tuning up, testing and calibrating your scope to the pinnacle. That's why Mike started the site 5 years ago and we have all benefitted. Good luck, and do not hesitate to get in touch. Clay Sherrod Arkansas Sky Observatory -----Original Message----- >I recently purchased the 125etx, and, so far, I am very pleased with it. I >am, however, a bit concerned that an instrument that costs close to $1000 >has had so many problems due to poor design or shoddy materials. Am I in >for trouble in the near future, and are these problems common to this style >scope? > >Thanks...very interesting and helpful web-site. > >tnorton
Subject: Re: Meade ETX Sent: Wednesday, February 14, 2001 09:22:26 From: sherrodc@ipa.net (Clay Sherrod) To: 2001as@bellsouth.net (Tony DeLuca) Regarding the ETX 125, I think it is the best portable telescope ever made. Some of them needs some tweaking at first (minor adjustments) but all is very simple and easy. Optically it is a masterpiece of work. Deep sky is fantastic for just a 5" aperture; globulars are easily resolved (the brighter ones) M31 clearly shows one dark lane, M33 reveals a spiral shape, and M42 is unbelievable; the planets are like looking through a large refractor, yet the colors are true and vivid. As you can tell, I very much like mine. The portability and ease of setup, combined with the wonderful GO TO and fabulous optics give me the best package I could ask for. Be sure and get one from a reputable dealer with the understanding that if it does not perform up to par, or if it suffers from mechanical problems (I would check it first if possible), then you can EXCHANGE for a new one....do not wait to send back for any kind of warranty repairs. Keep in mind there are some good ones out there and some that need work....they are turning out so many right now you really should inspect carefully. Mine is wonderful, but I did have a little work ahead of me when I got it, particularly in clamping difficulty. I was able to fix it myself thanks to the ETX site and all the helpful tips there. Good luck...if you get a chance to look through one, it may well be your present for NEXT Christmas. Keep in touch and never hestitate to write with a question or contact anyone from Mike's ETX site....there is a resource that never runs dry! Best is observing! Clay Sherrod
Subject: Re: ETX 125 and setup.... Sent: Wednesday, February 14, 2001 09:07:47 From: sherrodc@ipa.net (Clay Sherrod) To: gaudetr@nbnet.nb.ca (Rob Gaudet) It's good to do your research up front. As you might tell, I like the ETX 125 very much, primarily for its portability and ease of use. I had an opportunity very recently to trade up to the LX 200 7" Mak and turned it down because of the weight. I LOVED the LX 7" by the way, and if portability had not been a factor I might have gotten it....but I would have kept the ETX 125. I DID have some real problems mechanically when I got the scope; my biggest complaint so far has been the lousy customer service at Meade (they really are courteous for the most part, but haven't a clue about telescopes and astronomy); so regardless of what you get from them, that problem is a constant. My declination axis (and I HAVE heard of similar problems with both drives on the LX series 200) was so covered in grease internally that I could not get it to clamp and it put slop in the system; I had to get in there and clean all the gear works (and encoder) on both fork arms to get the clamp to engage and the motors to engage the gearwork properly. In RA, the clamp (the clutch plate, actually) has to be tightened so hard that it even still concerns me. I have been in there too, and opted to "wait and see" what happens; so far, so good. Mainly, minor things. Once you have the scope operations down (I mean the user knowledge) it works very well. Tracking is great and alignment is easier than on the LX200. Of course, it has less objects in memory, but the method of use (i.e., the logic of the Autostar) is far easier to maintain and keep up with than with the LX 200, which I do like by the way. All the problems I had were nothing I couldn't fix. My BIGGEST problem by far was the sorry instruction manuals that came with both the Autostar and the scope; you could throw them in the trash and you would learn it quicker. Had it not been for Mike Weasner's web site, I would have thrown in the towel, thinking (as a lot of people do, and those are the ones you hear complaining) that I had a bad scope when I really did not....just did not know all the basics, it turns out! Optically, the scope is fantastic, far better than Schmidt-Cass can ever offer in precise star images, planetary resolution, flat field, etc., etc. (have you considered the LX 200 7" Maksutov? It puts even the 12" Schmidt to shame....that is no exaggeration. It is a masterpiece. Be sure and get in touch; I have used so many scopes in my past (both professionally and as an amateur) that I am sure I could offer some assistance when time comes for that decision....best of luck! Clay Sherrod
Subject: ETX and Motor Vibrations Sent: Wednesday, February 14, 2001 08:15:02 From: sherrodc@ipa.net (Clay Sherrod) To: gaudetr@nbnet.nb.ca I read with interest your inquiry regarding the ETX 125 and motor vibrations. Some sleeping dogs never lay.... The motor vibration problems arose very early in the introduction of the ETX 125 and were noted in the review by Sky and Telescope magazine; indeed, the vibrations at that time were quite serious and I would have not even considered the telescope with that problem. Once out (Meade has a way of letting its consumers "field test" its product rather than doing it internally - cheaper that way, I suppose), the word got back and Meade indentified and quickly fixed the problem. I have an ETX 125 that has the finest optics I have ever used in a scope this size, particulary for a production item; the mounting, when it arrive (and even a bit today from time to time) needed to be tweaked to my satisfaction and I was a bit dissatisfied in the mechanics overall. Now that I have it up and running (by the way...a great deal of my initial problems were: OPERATOR ERROR! which I admit to very reluctantly) the telescope is wonderful and very satisfying to use. I have routinely used the telescope at magnifications 316x and above with beautiful Makutov-quality images that rival my 6" refractor. I have NEVER seen any motor vibrations AT ALL at any power! None. Not even when slewing at medium to low speeds at high power do I see any vibration; this myth needs to go away. I have used the LX 200 models of all sizes and have not seen any difference in precision nor vibration over teh ETX model telescope, except for INDUCED vibrations, those from tapping or bumping (even during focusing) in which the ETX because of its plastic construction is more prone to vibration than heavier units. It really comes down to portability; the LX200 7" Maksutov weights 59 pounds, not counting the tripod and accessories; shipping weight is 117 pounds; the 8" Schmidt weighs in at 52 pounds regardless of what you read....and so on. My ETX 125 weights 17 pounds bare naked. My heavy duty #887 tripod weighs only slightly more. One arm and I'm ready to hit the mountains! I can set up my telescope out of its footlocker and ready to observer in under four minutes. I hope this helps....good luck in your decision. I know it's a tough one, but I just wanted to let you know that the "vibration" myth is like like Elvis sightings. Just something that won't go away, because both of them "lived" once upon a time. Clear skies and enjoy your new scope! Clay Sherrod Arkansas Sky Observatory
Subject: ETX 125 and the Refridgerator
Sent: Wednesday, February 14, 2001 07:11:26
From: sherrodc@ipa.net (Clay Sherrod)
To: kentoliver@mindspring.com
Good morning Ken, and welcome to the ETX family!
Must say at the outset that you have provided a FIRST, at least for me,
by mounting your telescope on a refridgerator! Undoubtedly, this makes
for a very, very firm base....but where were the Police?
Seriously, I am glad you had such a great initiation with the telescope
and are enjoying it. They are super, and you enjoyment will greatly
increase the more you are familiar with it. You had a couple of
problems that sounded familiar:
1) Vibration - TAKE OFF THE RUBBER FEET; the telescope is a precision
optical instrument and not a coffee table decoration. Those rubber feet
are the primary source of scope vibration (but the keep the base from
scratching the furniture), and removing them will greatly improve your
perfomance.
The focuser is the main source of user-induced vibration and the problem
goes up significantly when you increase magnification. The flexible
focus cables that are available (see Scopetronix) and the electric
focusers are a great way to minimize; I use the Meade electric focuser
(which is not perfect, but I still like it) which totally gets your
hands away from the scope; vibrations are absolutely minimal and I
highly recommend this as a "must have" accessory for the ETX 125.
2) Declination slop - this comes in two fashions and I think you have
both; as Mike suggested, go to the ETX "Tune Up" on the web site and see
what you might do to tweak the problem. Most of the problem is all the
grease that Meade slops on the declination gear assembly, and using the
tune-up page, you can get in there and clean that grease off; it makes
your clamping much more firm as well; while in, check the worm gear
mount and make sure it is firm (but not too tight) against the DEC drive
gear; putting a little torque ("loading") on the drive gear will reduce
slop significantly.
If your are having trouble tightening the declination (altitude), there
is definitely grease where it should not be on the gearworks.
3) Viewfinder screws - I think we all are stripping out screws on the
viewfinder; at first I was tempted to replace the plastic ones supplied
with some good stainless, but then it occured to me that the tightness
(that strips them out) is also the main reason the find STAYS PUT after
you align it to the ETX; thus I left mine in and am very glad that I
did. You can get replacements by calling Meade customer service and
telling them what happened; there is no charge for the replacements.
I hope you thoroughly enjoy the telescope and look forward to you
observations on the ETX web site soon!
Clear skies...
Clay Sherrod, Conway, Arkansas
And from Ken:
Thanks for the warm welcome!
I am awaiting an 887 advanced field tripod which should be here by
this weekend. That should take care of any problems I'm having with
shake.
I think that it is probably the worm gear load that's poor. I'll
give that a look as well and see if it reduces the dec slop.
I'm curious how well deep sky objects will look in the ETX. I'm
still wondering if I should've dropped a few more bucks for the
LX-90. Any feedback on deep sky?
KLT
And from Clay:
Ken, you will be pleasantly surprised just how good the ETX 125 is for deep sky; I was a bit surprised myself and had developed a mindset that it would be okay but not outstanding; I was wrong; the contrast is fantastic and I am seeing detail in M42, globulars, and other deep sky I thought impossible in a 5" scope. The LX90 is a good scope (a bit less portable to say the least),but I personally do not like Schmidt-Cass. optical systems. I have had many of them and not really liked one, with less-than-sharp images at high power, and very low contrast at low power. If you are interested in deep sky astrophotography, then there is a distinct advantage there. By the way, have you checked out Rick Kjecki's planetary photographs through the ETX 90 (!!) on Mike Weasner's web site? It'll make a believer out of anyone just how much detail these little scopes can collect and deliver!And more:
From: sherrodc@ipa.net (Clay Sherrod)
Boy, do I envy you and those Arizona skies! I think you are right about
the LX 90; I have seen one and they are terrific scopes for optical work
and for some limited photography; they have all the AutoStar advantage
(actually I like AutoStar over LX200) and you are correct in the fork
arm construction.....beautiful!
I took my scope completely apart today (all day long) and adjusted the
RA drive, degreased and re-calibrated both Dec. and RA; man, it is one
tight machine! Good luck on yours.....on your fork arms, most of the
play is in the pivot cone "bearings" coming from the OTA support arms
into the fork arm holes; use TEFLON TAPE around those tapered tips (the
ones the setting circles screw into), lubricate with Lithium grease and
squeeze back into place; work them very well to loosen and that will
reduce you play and vibration greatly; also, where the OTA touches the
front of the support arms there is no support (opposite the two screws
each holding the OTA on). Use some inner tube rubber and rubber cement
and make an outline shape to glue to the inner edge of the OTA support
arms to shim against the tube; makes all the difference in the world!
Get in touch if you get stuck, or if something is not going well....be
happy to help!
Clay Sherrod
-----Original Message-----
From: Toliver, Ken
Thanks for the reply. I've decided that I'm going to get my ETX
completely tuned-up this weekend. I'm gonna strip her down and
re-assemble that puppy so It's tight as a drum. I really didn't
notice any RA slop to speak of, but the Dec slop is damn annoying.
I need to put something between the tube and those highly rigid
forks to tighten her up. Any suggestions?
I live North of Phoenix in Scottsdale, so clear skies are a normal
thing for me. The thing that causes problems is light pollution
from the city, therefore a filter is in my near future if I am to
see much deep sky from this location. I'd also be interested in any
suggestions you'd have there.
I tend to agree with you about the SC. As I mentioned in my first
review, I had an 8" SC that was pretty much as you described. The
only advantage is the wider field of view. I think I have interest
in the LX-90 due to the better set of forks for the tube mount (not
plastic). But I'll work with what I've got. So far, I haven't had
any of the problems noted by other viewers regarding random slewing
or such. So if I fix my Dec slop, I'll be a happy camper.
Looked at the photos, some of those are absolutely great for such a
small scope! I think I'll take a ride out to the desert as soon as
the skies clear this week and see what I can see! Now, the big
thing is to fine tune that finder scope...
KLT
And more:
From: sherrodc@ipa.net (Clay Sherrod)
To: Ken.Toliver@dayzim.com (Toliver, Ken)
Sedona sounds good right now, with the 7 inches of rain we have had
since Tuesday! Wrote a book one time with Sedona as a backdrop (And
Cahokia, Illinois). Anyway....
Don't strip any screws; wanted to alert you to the RA clutch, which I
just finished adjusting and cleaning on mine; under the TechTip Page,
be sure to print out the "ETX125RA Right Ascension Drive Fix" by Dr.
R.B. Ingersol, and then the "ETX125EC Right Ascension Lock Fix" by Doug
Loukota; both have excellent photos to assist you.
What I wanted to help you on is the disengagement of the RA clutch
mechanism so that you can CLEAN between it and the RA drive gear (the
small circular gear in the center of the scope base after you have
removed the bottom plate - CAREFUL WITH THE TWO WIRES FROM THE BATTERY
BOX!! I support my bottom plate by wedging between a metal base mount
(sticks up) and the pole that supports the 1/4-20 bolt to attach scope
to tripod (you can see in Doug's photo on left).
The clutch plate that Doug refers to comes off in an odd way; UN-DO THE
SET SCREW that holds you RA clamp on the top turntable before you take
the base plate off, and remove the chrome lever; this will be used as a
tool to loosen the large bolt that engages the clutch (you will see it
under the RA clamp); once the base plate is off (TAKE OUT THE BATTERIES
FIRST), then gently use the clamp as a wrench to slowly UNSCREW the bolt
OUT OF the clutch plate. There are two (2) wires which are guided
through a slot in this bolt, so be VERY careful not to turn too fast;
these wires go to your declination motor assembly.
At some point the clutch plate becomes very loose; AT THAT POINT no
longer use the "wrench clamp", but your hand to slowly back off the
clutch plate (it is threaded) until loose from the bolt; gently guide
the plate along the wires (the wires will be INSIDE the clutch plate
center hole) until you can get to the back of the plate to clean.
Using an emery board or medium grit sandpaper, gently buff off the
gear-side (that which presses against the gear) until clean and flat;
there are some punch holes which I used coarse grit to flatten; BE
CAREFUL TO COVER ALL ELECTRONICS AND OTHER GEARS UNDER YOU! I use a
cutout of plastic taped with masking tape to completely isolate all the
delicate stuff when working.
Once clean and smooth, de-grease using mineral spirits on both the
clutch plate, both flat surfaces of the drive gear (the gear slips off
the shaft, just wiggle away from the worm gear) surface plate - NOT the
teeth, and then the small surface BEHIND the gear that supports the base
turntable. Getting all this grease off helps two things: 1) locking of
RA and, 2) tracking.
Once clean, just reverse your steps to re-assemble; while the base is
open use your arrow keys and watch the small nylon gears to make sure
they are all turning without any slippage; this has been a problem in
the past, but I don't think so anymore. Mine have always been fine.
While in there, clean up excess sloppy grease which might become
dislodged during slewing and end up on the optical encoders!
Be VERY careful of the DEC arm wires when re-securing the clutch plate
and when shoring up the clamping bolt from above; do not allow them to
twist as you tighten.\
Once the clutch plate is engaged (it has two notches for pins to
securely fit against the drive shaft), reasonable pull together with the
"clamp tool" and close off the base. Turn scope upright and adjust
(with the clamp still loose) the bolt until you get the "action" you
like in clamping and unclamping the RA axis! Then re-attach the clamp,
being careful NOT to strip out the pesky little set screw, and you are
set!
I checked mine last night, after two adjustments (not happy with the
first) and it is tracking perfectly; I had some slight drifting from
slippage that is now completely gone. In addition, my clutch clamping
action was getting close to completely bottoming out, and I did not want
to clamp any further without further internal adjustments.
The time is well spent, and very easy to do; simply be patient and take
your time. Getting in a hurry can lead to sure disaster with all the
little soldered electronic components down there! Good luck...
.....but who am I to tell a guy who uses a REFRIDGERATOR for a tripod
what to do, for gosh sakes!!??
Clay Sherrod
-----Original Message-----
From: Toliver, Ken
Thanks a bunch, Clay. I really appreciate your input on this little
project. It looks like I'll be telling the wife that I'm tied up in
the garage this Saturday!
I'll get back to you once I get her tuned up (the scope, not my
wife) and let you know the results. Looking forward to my annual
retreat to Sedona in May; I'll go North up on the rim and find
myself an overlook area to set-up on. That'll give me some serious
deep-sky views!
Talk to you soon (as soon as I strip a screw!)
KLT (aka "the Fridge")
Subject: ETX-125EC Focal length Sent: Tuesday, February 13, 2001 10:49:37 From: edutton@infi.net Do we have an unresolved issue concerning the focal length of the ETX125? S&T claimed that is only 1650 mm in the Feb 2000 review and defended that in April 2000. They claimed that 1650 mm was the value to use in calculating effective magnification. I don't recall seeing further discussion. I've made numerous measurements of actual field of views (tele. fov)using different eye pieces, then calculated magnification (mag.) by (e.p. fov)/ (tele. fov) and then get tele. fl from mag. x (e.p. fl). I consistently get tele. fl 1850+ mm. The difference with S&T is outside likely errors of my calcs and meas. Am I missing something? I dont know how to actually measure tele fl. Thanks. EllsMike here: The focal length does change as the distance to the object is changed (focusing moves the mirror). Personally, I don't lose sleep over it. Purists may however.
And:
Doesn't affect my viewing pleasure either, just thought a 15% uncertainty in knowing ones magnification and or field of view might be concern to some, especially when we often use values to at least 2 significant figures for some quantitative endeavors. Just trying to raise the bar a bit, maybe. I suppose people who really need this information know how to determine it. Just wondering if a f/13 scope sells as well as a f/15 where one of the hooks is power per inch, and the competition is close to f/11. Didn't impact me, I liked the color along with the potential for pointing to where it was told to. Cheers, Ells
Subject: The Agony and the Extasy Sent: Monday, February 12, 2001 17:13:22 From: saber@dircon.co.uk (Saber Properties Limited) I finally did it, I bought a 125 today. The weather has been terrible for about 4 days with unbroken clouds all night so I didn't expect to use it tonight. Amazingly by the time I got home from work the sky had completely cleared leaving a fairly black cloudless sky. I was overcome with anticipation and could barely wait until my kids were in bed (I have 4 kids between ages 2-8). As I opened the box everything went like dream I inserted the batteries and took the scope outside and guess what......... the damn thing wouldn't slew to the right. All other directions are ok but it is completely dead when I press the right arrow. Have you come across this b4? I couldn't waste the clear sky so I took to the sky manually and Jupiter with 4 moons was high in the sky and was just able to make out some coloured bands across the disc. I then had a look at the orion nebula which I have seen many times in miniture through my binoculars, but was able to fill the fov on a 24mm and most of a 9.7mm. After some general scouting I located saturn for the 1st time ever. Although it was small and not very clear at all, it was still an awe inspiring sight and it had me jumping up and down. I had the 125 resting on my rabbit hutch so it was deciddly wobbly, so my next purchase has to be a tripod. Do you not feel the heavy duty tripod would be too cumbersome in the long run. The shop I bought the scope from do a tripod called the Tri-wedge, its alot heavier than the standard meade tripod and they swear by it, have either of you heard of it. Regards to you both, SamMike here: Congrats. Sorry to hear about the slew problem. I suspect either a bad controller or bad drive. I suggest returning it to the dealer for an exchange. Never heard of the Tri-wedge. Let us know more if you get it.
And some more thoughts:
From: sherrodc@ipa.net (Clay Sherrod)
Sam- GREAT! We are really happy for you....and don't panic about the
failure of your unit to not drive in one direction. It is a new scope
and I will give you a couple of tips to "convince" it to move properly;
we'll have you up and running in not time.
I don't know if you have ever read any of my articles on Mike's site
regarding first impressions, but your "dance" after finding Saturn for
the first time is exactly what I tell people they will do. You NEVER
will forget our first look with your own eyes of Saturn through your OWN
telescope.
Now let's tackle your issues:
1) Azimuth/Right Ascension Motor not tracking in one direction. Sam,
this is common for a new ETX 125; the smaller ETX 90 does not suffer
from this as much because (I think) there is less mass to move. Two
things are in play here: a) your clutch is likely slipping a bit
because it is either new and does not want to engage easily or, b) the
lubricants and/or clutch assembly have not SEATED in properly as yet and
need to be "convinced to do so." Regarding the clutch; my ETX 125 has
to be tightened significantly in order for the base drive to initiate;
DO NOT OVERTIGHTEN, as the clamping knob is PLASTIC, not metal as it
appears and it will break easily. Nonetheless, you MUST clamp securely.
I ALWAYS test my RA (Azimuth) axis motor prior to aligning for the
night to make SURE that the clutch (clamp) is engaging the drive gear.
I, too, experience one axis which moves more readily than the other.
Try these three things to break your scope in:
a) after initializing your telescope, you will be able to use your
SLEW (arrow) keys (are you using the standard hand control or do you
have AutoStar?); clamp the azimuth clamp firmly until you can get
the "left"-"right" arrows to move the telescope; once there, slew
the telescope 90 degrees in one direction and return; then slew 90
degrees in the other direction; this process is spreading the
lubricant of the drive system and also allowing for "marrying" of
the clutch to the drive gear.
b) I found early on that UNCLAMPING the telescope when new and
simply rotating the entire turntable of the azimuth over and over
again helped greatly to help distribute and seat the lubricants; in
addition it reduced the "tightness" (which is one reason you are not
moving in one direction) overall whe manually (unclamped) moving the
azimuth.
c) your scope will be reluctant to move (sometimes in EITHER
direction!) after it has been sitting unused for a spell, even two
or three days and clamped securely; if it has been sitting, and
prior to taking it out to use for the night, UNCLAMP THE AZIMUTH and
rotate manually to "loosen it up.;" then reclamp securely and
intialize for a "dummy" run to activate the motors (after you enter
daylight savings time or "no" on it). Once again, check your motors
to see if your clutch is doing its job; if not, tighten
every-so-slowly until it does. You should do this every time you
take it out.....BEFORE aligning for your night's observing.
2) Concerning the tripod...yes, you will definitely need a good tripod.
I will reiterate that I believe the Meade #887 is perfect for the ETX
125; I, too, shopped around and found beautiful tripods all over the
place and ended up spending less money for more stability than on a
quality photo tripod. The #887 is NOT HEAVY, it just looks it. It
folds up as small as the smaller #883 and can easily be carried (even
with the polar wedge and adapter plate on it!) in one hand! Yet when
the legs are extended it is as stable a base as a permanent pier.
Actually, I have a large Bogen photo tripod I use with a Bronica 2-1/4
camera that weighs more and is far more flimsy with the ETX on it, as
the telescope "rides" too high atop the photo tripod, as is the case
with all of them in my opinion. I wish you could see one first-hand;
they are so well designed for portability that you really cannot believe
at first how stable they are; I was shocked by the weight and
transportability. By the way, I have a signficant "lift-and-carry"
handicap that impairs my ability to walk with heavy objects, yet I can
easily move my tripod and wedge anytime I want! It weighs about the
same as the ETX 125.
Well, I hope this helps. I am really glad you got the ETX 125 and it
sounds like you might be as well. Stay tuned to Mike's site to help you
along the never-ending learning path to make your enjoyment even better!
Good seeing and clear skies!
Clay Sherrod
Arkansas Sky Observatory
And the answer is:
as it turned out it was the standard handset which was broken, and am looking forward to another nights viewing P.G. Thanks for the tripod advice Clay, though so far most of the UK dealers (there aren't that many compared to USA) don't stock the #887 tripod. Do you know of a dealer that will ship to UK from USA? Cheers, SamAnd one other thing:
many thanks, honestly I don't know how you find the time to everyone that contacts both you. There are a lot of people praising you both on Mike's page and they do not exagerate. More power to your collective elbow. Regards, SamAnd from Clay:
Sam - thanks, and I need it today; it is particularly rough. I am having trouble at the observatory (a major lightening hit this morning wiping out my photoelectric equipment and most of my computer/electrical hardware); I am on my way up there right now....and of all days! I have - at last count - 113 unanswered letters that came in in the last 2 hours. But, anyway, all that being said....I ALWAYS have the time for a fellow enthusiast! Never hestitate to ask or just to be in touch! I am sure that Mike (he is at least as busy as I) feels the same way. As they say here, the guy you ask to chair some committee is the same guy who everyone says "....but he doesn't have TIME for any more!"
Subject: EXT 125....your opinion. Sent: Monday, February 12, 2001 06:37:12 From: gaudetr@nbnet.nb.ca (Rob Gaudet) Was thinking about purchasing an ETX-125 meade telescope. Heard of motor noise vibrations problems.... Overall, what is your opinion of this scope. I am torn between an 8 inch Lx200 Meade SCT (due to shortage of money not possible), and the ETX-125. Many Thanks, Robert Raymond Gaudet, B.Sc. gaudetr@nbnet.nb.caMike here: I'm not seeing this with my ETX-125EC but some others have. Others have not reported this problem. Lots of variables in play in how each individual user sets up and uses the system. That's not to say there isn't a problem in the scope of those experiencing the vibration.
And:
Guess it would be better to hold out and put more money aside for a scope like the 8 inch LX200 SCT. I really would hate to put down this much money on a scope only to have it give me motor vibration...but according to Sky and Telescope reviews, there was an insert that said that this problem has been address or can be corrected by diffrent setups as you have mentioned. How do you like the ETX-125EC telescope.?Mike here: I like it fine.
Subject: ETX-125EC Review Sent: Sunday, February 11, 2001 21:03:25 From: kentoliver@mindspring.com (Ken Toliver) I finally got a chance last night to take my first run with my new ETC-125. Handicapped by the lack of a tripod (still waiting for an 887 to get in stock) and using a small refrigerator as a table base (yes, I did say a refrigerator), the results were great. The good: Having never used it before, and without the darkest sky, I set it up in alt/az mode. I fully expected to have some troubles the first time out. I set it in home position and pointed it roughly towards Polaris. Knowing that my latitude is around 33(, I slewed it up to 33( and centered Polaris with the directional keys (I did not get finicky and try to move the whole base to center the star). I then dropped it back down to ( (horizontal to the ground) and ran the easy alignment with my Autostar. After aligning the first two stars that it picked, I entered Jupiter as the GO TO. Bang! There she was with four moons and several easily discernable bands. I remind you, I was not tedious about my setup; in fact I ripped through it in no time. Next was Saturn; great tilt on this planet with the rings and Cassini division viewable. On to the Orion nebula, Plaides, and a few others. None of them were directly in my field of view and required a slight adjustment using the viewfinder, however, I am sure with some fine tuning of the viewfinder I can get more direct hits. Optics; in a word: fantastic. I had an 8" Schmidt Cassegrain that didn't pinpoint stars as well. The bad: Focussing is definitely a hassle, especially in alt/az setup. Everything moves on those rubber legs. And using higher powers makes it worse. I definitely will be looking into a decent cable focus or electric focus. I am looking forward to a good, solid tripod. I also seem to have some slop in the declination plane. For example: if I set my declination at 90( (straight up) and push the tube I can move it approximately 1/8 to 1/4 inch back and forth. This can cause movement when pressing against the eyecup of an eyepiece and moves the target off center. I need to investigate whether there is an easy fix for this. The viewfinder holder is made of plastic and easily strippable; I already stripped one screw. Be careful with these! But all in all, I am very pleased and look forward to spending more time in a dark sky location to really put her through the paces! I highly recommend this scope! KLTMike here: Some slop in both the RA and Dec axis is normal for the ETX. You might be able to apply some of the Tune-ups shown on the Tech Tips page.
Subject: Wrong Barlow?? Sent: Sunday, February 11, 2001 16:26:23 From: srife@swbell.net (Stan Rife) I bought the #140 apochromatic 2x Barlow at the time I purchased the ETX 125EC. Will this Barlow work with my scope? I have only had my scope for a couple of days (had to return the first one to Meade for a replacement) and have not had an opportunity to try and use the Barlow lense. Matter of fact I haven't even had time to properly set up the scope with the Autostar yet. I just did some off-hand viewing last night, out in my back yard, and was able to see the cloud bands on Jupiter AND the rings around Saturn...all this with just the 26mm eyepeice. I was astonished! The images were crystal clear as well, except for when the clouds got in the way. I can't wait to try out some additional magnifications. I also bought the 40mm eyepeice, as well as the 15mm. Someone suggested that these 3 eyepeices along witht the 2x Barlow would give a good range of magnifications. Also bought the variable polarizer for looking at the moon. I sure hope I didn't buy the wrong 2x Barlow. Stan Rife Houston, TX srife@swbell.netMike here: Doing a search on the site for "#140" finds several answers to your question. In short, it works but you probably spent more than you have to as the #126 works well with the ETX-90 and ETX-125EC.
Subject: ETX 125 vs. 5" refractor Sent: Saturday, February 10, 2001 18:43:57 From: sherrodc@ipa.net (Clay Sherrod) To: saber@dircon.co.uk Sam, good evening - As the proud owner of both a 5" ETX 125 and a 6" Unitron Refractor, I can say without a doubt you will be more than pleased with teh ETX 125. My initial tests of the instrument absolutely astounded me. While there were mechanical issues that I needed to address easily, the optics are the finest I've seen. For deep sky, the ETX outperforms the 6" refractor and an 8" Schmidt; for planetary they are essential equal, although the ETX is not as stable (the Unitron with its pier weights about 870 pounds) with vibrations. But I CAN pick up the ETX 125 and put it in the back of my car for a remote site trip to....the Unitron stays home. The field of view is perfectly flat at all magnifications; I get some coma using a 40mm wide angle Erfle, but this is from the eyepiece, not the scope. There is extremely little chromatic aberration from the corrector and NO coma. I can routinely use magifications of 370+ on good nights; star colors are true. It really is a great scope...portabity, high tech, optically perfect, and simple to operate. Any of the seemingly too-common mechanical glitches can usually be taken care of by reading the many instructive posts on Mike W's ETX site. Let me know if I can help you further, and good luck in your decision! P. Clay Sherrod Arkansas Sky ObservatoryAnd a reply:
Thank you for your response, I had seen your name cropping up all over Mike's website but wasn't sure if you were happy to be sent unsolicited enquiries. Your's and Mike's answer pretty much settles my concerns, I had virtually made up my mind to get the 125, I suppose I just needed to hear from an independant experienced astronomer who has no vested interest, that it's a good scope. The stores that I have spoken to, almost all seem to be trying to push their particular preference, which is very frustrating, when your'e trying to get solid unbiased advice. My main concern was whether most of the purchase price (here in UK it costs 999 (pounds) for the scope alone, no tripod, no autostar) was going toward the autostar and drive system with the optics just being avaerage for the aperture. Anyway you and Mike are to be commended, and you should take pride in that there are many budding astronomers out there who wouldn't have kept up their enthusiasm without guidance and help from you both. Thanks again. SamAnd from Clay:
Glad to help! Mike started the ETX web site in 1996 to assist ETX users worldwide, just as you have experiened. I am glad you have decided on the ETX 125, as it is a fine instrument! Keep in mind that your use of the web site is not limited to advice on picking out the telescope. When you get your -125, don't hestitate to post an inquiry if you need help with instructions or problems that you may encounter. BE PATIENT and learn the telescope slowly; the new technology can be frustrating to a novice, but eventually they are a joy to use! Please do not hesitate to contact me if you need further help, or post on Mike's site for the help from many other qualified ETX users out there! Clay SherrodAnd more:
From: sherrodc@ipa.net (Clay Sherrod)
Sam, no problem in asking!
I will give you an honest opinion and that is purely what it is,
opinion. I almost hate to admit, but I have either owned virtually
every visual telescope there is, from observatory giants to tiny
Questars. Many are excellent and many inferior, and to me - the PERFECT
telescope is one that fits all of your personal needs.
To be honest, every telescope I have owned has had at least one major
flaw or problem; some severe, some fixable or tolerable. I have run the
gamot of large telescopes and astrophotography, and scientific astronomy
so perhaps my viewpoint is a bit biased.
I want to be happy, satisfied and without any regrets every time I take
my telescope outdoors. Many telescopes will not provide that feeling.
Many times I have said that larger telescopes (yes, even 8" Schmidts)
become "white elephants" and the owner will think and use EVERY EXCUSE
known to simply keep from taking all of it out each night.
Personally, I do not like the optical performance of any
Schmidt-Cassegrains, and have used such telescopes up to 24" diameter;
the images are always less than sharp, stars appearing "almost" focused,
and planets of lower contrast that with even a Newtonian reflector.
On the other hand, the Maksutov, because of its correction and
relatively small secondary can attain images, as I have decribed to you,
equal to large refractors. Personally, I would not own an eight-inch
Schmidt Cass. when I could have the ETX 125, but my use is likely
different from yours; if I was into astrophotography, I would elect, not
for the LX 90, but for the f/6.3 Schmidts (8" & 10") that Meade makes;
the LX90 would be totally out of the equation.
My scope is optically perfect, mechanically so-so (I have customized all
of the drive system to my satisfaction), and the most portable medium
sized scope there is. Plus, you add in the computer, the accessories
available, the quick set-up time, the ease of storage and transportation
and the overall observing comfort that comes with it....it is my ideal
telescope. It did not arrive that way....I had to MAKE it that way.
I would like to make you an offer: whichever telescope you decide on,
PLEASE consult with me at any time concerning OUTFITTING (i.e.,
accessories, tripods, etc.) so that you, too, can have a telescope
customize to YOUR observing requirements. Too many wonderful would-be
enthusiasts fall prey to advertisements, false claims and over-zealous
sales personnel. I will be happy to assist you, as will the many fine
contributors to Mike Weasner's web site, with any telescope you select
and any problems or questions that you may have.
Contact me anytime....CLAY SHERROD
-----Original Message-----
Sorry, 1 more question.
If my ultimate aim, assuming my interest in astronomy increases, is
to buy something like an LX90 or perhaps even an LX 200, which give
the option of astrophotography.
Do you think it still makes sense to spend 1000 on the 125 which is
over half the price of the LX90, or is it worth considering the ETX
90 for the while.
I have considered that I might find the 125 is all the scope I need
and will not feel the need to go bigger.
What say you?
Regards,
Sam
Mike here: I agree that for serious astrophotography, more top-of-the line is required. However, as seen on my site, you can do amazing things with lower end scopes! Just requires a lot of patience, perhaps a lot of film, perhaps lots of time, and generally lots of luck!
And from Clay:
From: sherrodc@ipa.net (Clay Sherrod) Mike - Right you are....Rick Krejci has proven that "size does not matter" for observatory-quality astrophotos! I guess I was referring more toward deep sky in reference to the f/6.3 than to projection photography. Great points, though - particularly the "...lots of film" part. Boy, don't we know?! ClayAnd a reply:
Thanks once again and I will take you up on your offer and feel certain that I will need advice on a tripod, which will be my next purchase. I will initially be using my Manfrotto tripod (Italian proffessional camera or lighting tripod) until I decide which tripod to buy. I know it will be totally unsatisfactory in terms of stability and certainly won't be polar aligning it. I have my eye on a tripod which is made to order by BC&F LTD Telescope House (in London), they say its stronger and more stable than the field tripod offered by Meade, I will let you know the model once I have got the details, perhaps you've heard of it. I've seen your comments on Mike's site regarding selection of oculars worth starting with and will bear that in mind. Many thanks once again. SamAnd from Clay:
Sam, without a doubt the BEST tripod for the ETX 125 is that made for it: the #887 Heavy Duty tripod with wedge and ETX 125 adapter assembly. It is very stable (2" steel tubular legs and solid cast aluminum plates) and yet very easy to fold up, carry and store. The weight of the tripod is remarkably light considering the solid base it provides. I am 100% sold on it; the #883 tripod should NEVER be considered for the -125; it is frail and makes the unit top-heavy. The difference in the two is day and night.
Subject: Meade ETX125 Sent: Friday, February 9, 2001 21:56:05 From: peterspagnoli@yahoo.com (Peter Spagnoli) I was debating between the Meade LX90 8" SCT and the Meade ETX125. I think I am going with the 5" since I prefer the Mak-Cas optics over the SCT (plus I am not sure how portable the 8" is). I don't plan to do astrophotography.. do I need to get the upgraded field tripod for the ETX125 ($350) or can I get the deluxe field tripod ($199)? Please let me know. PeterMike here: Stability is much better and vibrations are minimized with the higher priced tripod. The lower priced tripod is less stable and more prone to vibrations, especially if you fully extend the legs and/or use the ETX-125EC is polar mode.
Subject: ETX-125-Tabletop legs.. Sent: Thursday, February 8, 2001 18:12:49 From: bryan@softdisk.com (Bryan Vekovius) I have been very enlightened by your site, and am looking forward to purchasing my ETX-125. I have been debating over the ETX-125 and 90 as well as the Nexstar 5 ever since a friend bought the ETX-90. He has the tabletop legs, autostar and case and it is so portable! I am wondering about the functionality of the 125 with the tabletop legs, and whether the "FIELD TRIPOD" is necessary. I have an older 4" reflective which is a true pain to take out and use because of the size and transportation of it with its bulky tripod. Of course, I like the portablility of the ETX-90 and am selfish (I want a better view of the sky) so I want the light-gathering capability of the ETX-125. Am I going to be happy with the purchase of the ETX-125 with the "tabletop" legs for my "portable" telescope, or am I going to realize once I purchase the scope that a much heavier tripod is NECESSARY for everything that I want to do? Any help is greatly appreciated. Sincerly, Bryan Vekovius bryan@softdisk.comMike here: If you get the Autostar, you can use the ETX-125EC in alt/az mode and just set the base on any flat sturdy surface. No need to tilt it to match your latitude, which is what the tabletop legs do. From reports, I would say that the tabletop legs are really just for emergency use when carrying a tripod/wedge is not convenient. The legs don't do much to dampen out vibrations and at some low latitudes may even be unstable. But it you need/want a tripod check out the comments on the Accessories - Tripods page and search the site for "tripod".
And more:
Thanks for the quick reply.. So skip the tabletop legs? I suppose the advanced tripod is what I want? I noticed the LX-10/50/90 has a pretty sturdy looking tripod and it seems to cost less. that, coupled with the adapter might be another option? I noticed on the site a few people recommend the Zoom lenses (one recommended a NIKON and others rec. meade and Televue) and some "scopetronix" lenses. Personally I don't know the difference between 9 "coats" vs 2 "coats" and Plossl vs super-plossl and the difference between series 3000 (which appear to be less expensive) and series 4000 Meade lenses.. What do you think? I went to scopetronix site and they recommend the 2x barlow, then the 40mm then the 15mm.. with the 26mm supplied, that makes: 7.5, 13, 15, 20, 26, 40 Does that make sense? Thanks for all the help, the internet makes finding an expert on all of this very easy.Mike here again: Well, the advanced tripod for the ETX-125EC isn't inexpensive but gets positive reports on stability. As to eyepieces, depending upon your expectations, eyesight, and usage, lots of different styles may yield similar enough results that getting an inexpensive one is just as good as getting an expensive one. If you want the best, spend money. If you want also the best you can spend less. If you want OK you can spend even less. If you want junk you can really waste what little money they cost. For most people, the Scopetronix line seems to work out OK. For others, higher quality (and cost) may be required. That range of "focal lengths" is perfectly acceptable.
Subject: Re: ETX 125 or LX90 Sent: Thursday, February 8, 2001 10:28:37 From: saber@dircon.co.uk (Sam) Whilst cost is an issue, its not the overiding factor. My main cosiderations are portability and optics. In terms of optics would you say inch for inch say the etx 125 would far outperform a 5" refractor (not apo) , because I not entirely sure that I want to pay so much which essentially is for the drive system and autostar. As you can probably tell, I am having the same problem many people have when they are buying their 1st scope (though I have briefly used etx 70), its so hard to decide which type to go for. I would welcome any of your expert advice you can give me. Many thanks, SamMike here: Well, a reasonably good 5" refractor will probably cost more than an ETX-125EC. If you get one for less than the ETX-125EC I suspect the optics will show it. Optically, the ETX-125EC is a fine instrument (as many have commented on). If you really want to be sure of your purchase, visit a local astronomy club and try out different instruments.
Subject: ETX-125 electric focuser Sent: Thursday, February 8, 2001 07:56:35 From: 110641.1527@compuserve.com (Bob Thompson) Tuesday I finally received the Meade #1247 electric focuser ($119.00 incl. shipping) from the Sight & Sound Shop. This item was on back-order for a long time, but this vendor allows you to check on the progress of your order via his web site. He also let me know the progress of my order via emails. That's about all you can ask for. This is a good vendor, knowledgeable about the product and patient with people who are new to this. Last night there was finally enough clear sky to give it a try, and I can only say that it is GREAT! Clay Sherrod is right - this is the only way to go. It installs in just a few minutes with no effort. Focusing is easy, smooth, & precise. Perhaps it's my imagination, but the image shift while focusing seems to be diminished. While waiting for the electric focuser to arrive, I built the flexible focuser as described by Doonr elsewhere. It did allow smoother focusing, but that advantage was offset by my clumsy habit of bumping the focuser stalk during viewing & inducing vibrations into the scope. Also, I didn't like the torque that was applied to the focuser shaft when the scope was at higher altitudes and the flex cable had to do a 90 degree bend. After a couple of nights I took it off & went back to the knob until the electric focuser got here. Once you get past the birthing pains the ETX-125 is great.
Subject: Re: EXT-125 questions Sent: Wednesday, February 7, 2001 11:21:32 From: sherrodc@ipa.net (Clay Sherrod) To: Paul St. Amand Paul - GREAT news! Boy, that is some service; glad you called them. I think they might even check it out well before sending it this time! Let us know how it does. By the way, I stick to what I said about the zoom eyepiece; if you have a change to compare say, a 20mm Meade 4000 Erfle against your zoom set at 20mm you will be amazed at the difference in brightness, contrast and sharpness, not to mention color and resolution. I wish that zooms indeed were the "fix all" for many eyepieces, but they are not. Regarding brand, I still stick with the Meade 4000 PS series as the best for the money (and even for more money!). I have used them all and still, that is what I use (matter of fact I have a new one coming in today!) Great news, and I am happy for you...give us a complete report! Clay Sherrod -----Original Message----- Clay, Assuming you where correct about Shutan being out of ETX-125's, I called Meade. They were willing to send me a new scope ASAP (3-5 days). And I will just return the old one in the new package. This way, I get a new scope as soon as any other way and Meade pays all shipping! Thanks for the suggestion. Once the new scope comes in, I will try the zoom again and see if it was the scope or the zoom that gave poor images. If I am still not happy with the zoom, then I will ask Shutan to take it back and just get fixed focal length eyepieces. If I do get new eyepieces should I stick with Meade or is there some other brand that is significantly better for not too much more money? Also, are the wider angle of view eyepieces as sharp as the standard 52 degree meade plossls? Many Thanks, Paul
Subject: ETX 125 or LX90 Sent: Wednesday, February 7, 2001 06:34:43 From: saber@dircon.co.uk Having only recently fallen for astronomy, I've been using 7X50 binoculars for a few months, which themselves have been a revelation. I now wish to purchase a scope. I recently attended the Eurofest and purchased an ETX70 as a starter scope. Whilst its an improvement on the binoculars, I think I had set my expectations too high and I now feel that I need to make a significant step up. Whilst I realise that in absolute terms the 8" of the LX90 is always going to beat the 125, I do need a certain amount of portability since I live in inner London England and although I can get observable conditions, I will want to go into darker areas in the country side and I am concerned that the LX90 will be too unweildly. To put it in a nutshell, is the 125 considered sufficient for all but the highest levels of observations or is there a vast improvement on the LX90 and worth sacrificing the portability of the 125 and paying the extra cost, which in the uk is about 700 pounds ($1000 approx)? Top website!!! SamMike here: As to LX90 vs ETX-125EC, I've not yet actually used an LX90 (although I've seen one in a store). Certainly the ETX will be more easily moved around but you are likely to pack either one in a case(s) for transporting. So no advantage of one over the other in that respect. And there is the larger aperture, and the reported better mount of the LX90, which would be an advantage of the LX90 over the ETX-125EC. But then there is the extra cost of the LX90, so advantage back to the ETX-125EC. Decisions, decisions, decisions...
Subject: azimuth slop and slew hesitation Sent: Tuesday, February 6, 2001 06:32:26 From: sherrodc@ipa.net (Clay Sherrod) To: nunosilva2000@yahoo.com.br Good morning! Sorry to hear that your ETX 125 is experiencing a "lazy" azimuth condition! Your times really do seem to be somewhat troublesome; you might check under Mike Weasner's Tech Tips/Tuneups/RA drive postings to note that several similar situations have arisen with the ETX 125, and in one case was simply a nylon gear in the azimuth drive train NOT being locked down as it should be. Are you tightly clamping your azimuth lock? I have to watch mine, for slewing, for GO TO and even for tracking, as many times the clutch does NOT engage the RA (I use mine in Polar alignment) tracking. Concerning the "slide" you mention; mine, too has a substantial backdrift to the WEST each time I attempt to center at high power. It is quite noticable; I have had this problem in BOTH Alt-Az and Polar alignements, so I think it is something related to the drive mechanism itself (hardware). On your times (good thing to measure), what power were you using? With a 26mm eyepiece, I have extreme difficulty noting any perceptible motion at 73x, even though I KNOW the scope is moving; at 156x, the motion becomes more evident. It may be that your scope is moving and you simply cannot discern the motion. PLEASE NOTE: Rarely will find an object at 73x in the field of view (FOV) after a GO TO slewing. Usually it is close enough that it can be centered first in the finder and then in the main scope. Of course, the closer your initial alignment is, the better your "location" is listed (latitude and long.) and the more accurate your time entered, the closer you will be during GO TO operation. Good luck...if your delay times continue to be what you are reporting, even at higher magnifications, I would consider an overhaul (or at least check out how you might fix yourself) of the azimuth drive. I wish you well.... P. Clay Sherrod Arkansas Sky ObservatoryAnd a reply:
Thanks for writing! I always tightly lock the RA lock, otherwise, the motor wont move the scope. Because of this, ive recently broken the RA lever, which is made of plastic (it should be metal!). Then i detached the rest of it and used a fork spanner to tighten the lock. Soon, i discovered that the tighter it was the smaller was the delay when changing the way of rotation. Unfortunaly, the dec motor stopped working and the RA lock could not be tightened again (i must have forced it too much and damaged the wires). Now im having my etx repaired in Spain, the nearest Meade workshop. When i measured my times i used my 9.7mm e.p. (196x) so there was no problem but i noticed that the scope moved really slowly at the desired way for some seconds before it moved at the correct speed, which was much faster (i used the second to measure my times). Well, i hope my etx works better after repair. Yours, Nuno SilvaAnd more from Clay:
Sorry you have had misfortune with your ETX 125; I noticed that Mike Weasner had sent you a cautionary note yesterday after I wrote reminding you to "not overtighten" the lock clamp on RA. Too late; may others have done the same thing, thinking the clamp was metal. I cannot understand why the DEC motor would stop after clamping the RA tightly unless a wire was pinched under the clutch; the way it is all arranged in the drive base, this is not likely to happen. If I understood you correctly, you were using the 9.7 mm which should have given you about 200x for your timing tests (?). If you were using that magnification, your delay times are way too long. I too notice the slow "creeping" of the object when slewing at low speeds prior to it actually taking off at the correct speed; I have just gotten used to it. If you mentioned the problems when you took your scope in for repair, perhaps they will look it over well and get it in great shape. Let us know how it does when you get it back...I'm anxious to know! Clay Sherrod
Subject: ETX-125EC Power Adapter Sent: Monday, February 5, 2001 12:39:00 From: omar@cards.cncdsl.com (Omar Mohamad-Bernal) I was wandering if you can tell me what is the minimum require mA (milliamps) of the Meade power adapter #541 for the ETX125-EC. Thank You! Omar…Mike here: According to reports, the Meade power supply is rated at 1.5 amps.
Subject: ETX 125EC Sent: Sunday, February 4, 2001 17:35:38 From: nunosilva2000@yahoo.com.br (Nuno Miguel de Freitas Silva) Im Nuno from Portugal and im wrinting to let you know some problems ive been experiencing with my EXT 125EC for a long time and havent solved yet. Perhaps you could help me. I have my EXT since last summer and ive been using and testing it intensively since then. Ive tried to pacient but some problems i have with my scope seem to be too evident: 1) RA slew slop. At first, i thought the delay when changing the way of the rotation in the RA axis in my telescope was normal, since i had read about that in you site, but after, i found out that my delays were much longer than normal (see table below) when compared with Clay Sherrods times. I also experience a little slide on the same axis after stopping pushing the slew button. On the altitude axis, the only problem i found is a small jump (about 1 or 2 arcmin) when changing the way of the rotation, which can be a bad thing if you are trying to do a precise guiding. autostar my delay/ Clay Sherrods delay/ slew speed seconds seconds 9 (5/sec) 1.0 <1 8 (4/sec) 1.0 7 (3/sec) 1.5 6 (2/sec) 2.3 5 (.75/sec) 4.5 <1 4 (32x sid.) 7.7 3 (16x sid.) 14.3 2 (8x sid.) 27.0 6 1 (2x sid.) - - 2) Autostar pointing precision. My autostar/etx never worked very well. Ive tried a good alignment about one hundred times but no one put every object (or almost every) in the 26mm e.p. field of view. Ive trainned the drives the best i could (using 2x barlow+ 26mm e.p., waiting for scope to cool down) and i centered the alignment stars the most precisely i could and the best ive ever accomplished was having 86% of the objects in the field of view (most times only half of them). Maybe this problem is a consequence of the first? Here is some data about the performance of my etx/autostar: align. stars number of objects accuracy Capella/Rigel 12 50% Rigel/Pollux 5 60% Dubhe/Menkar 22 86% Nunki/Almaak 21 43% Capella/Sirius 9 33% Castor/Rigel 10 60% Rigel/Procyon 31 48% Note: objects were chosen from different parts of the sky. Do you think my etx should be sent to Meade for repairing (RA gears)? I would be grateful if you could advise me. Yours, NunoMike here: There is some slewing delay, especially at the slowest speed. You didn't specify which Autostar version you have but if not 2.1ek you might want to upgrade it (if you can). That might fix both the accuracy and slewing over whatever version you have. That might make it unnecessary to return the scope to Meade.
Subject: Re: obstruction Sent: Sunday, February 4, 2001 12:18:25 From: sherrodc@ipa.net (Clay Sherrod) Ells - Thanks for getting back...no, don't own stock in Meade and they make me as hopping mad as they do anyone else! On a large scale, I just happen to like the products they put out! Regarding the 40% obstruction, no I did not ignore that fact; I was evaluating the overall performance of the system. With such perfomance (optically) that I get from my ETX 125, I really forget it's there, and actually I could care less! (Well, maybe not exactly....I can only think about what it would be like if the obstruction was NOT there!) The images are remarkably crisp in my telescope, both stellar and planetary. All I can offer is that perhaps the DESIGN of the entire system, not just a single component of the system, is responsible for the good performance even with such an obstruction. After all, you are indeed right in that the secondary baffle provides a 40% (actually like 38.7%) obstruction. Yes, I did see the book review you mention and I must admit that I will buy the 5" telescope that can achieve a stellar limiting magnitude of 13.8. All the super-enhanced coatings in the world can't help you there. Overall, Meade does need to do a lot of work with its customer service department and needs to improve quality control of its product PRIOR to shipment. Nonetheless, it is remarkable what they can still put out for the price; I do, however, pity the poor soul who gets one that slipped by....there have been some real problems out there, but keep in mind it happens to ALL manufacturers, particularly when you have something as hot as the little ETX scopes. In about a week I will have an opportunity to field test the LX 7, 7" Maksuktov and am really curious to see if the performance optically is proportionate as one should expect for the increased aperture. I have heard good things about it.....it will be interesting to see. However, a note: the LX 7 features a central obstruction far less than the ETX scopes, even though the optical design is by nature the same. Curious. Thanks for writing - Clay -----Original Message----- From: Ells Dutton >Clay, > >Also, wanted to mention, and get your response to, my novice opinion >that the major optical drawback of the ETX-125 must be the 40% diameter >obstruction of the secondary mirror (actually the baffle) By all >accounts anything more than about 25% has detrimental effects on >resolution translating to image sharpness. Your review seems to >discount this aspect. > >One other thing, Are you a share holder in Meade? (you don't need to >answer) They went public a while back and I had wondered about the >wisdom of investing. They have come under a lot of fire since >introducing the -125 line but before that I thought they had a stellar >(pun intended) reputation. Now it seems to me that customer service is >also lacking and alot of the ETX problems are real. Probably is not too >realistic to think that most consumers would have your or my >determination. > >By the way, did you see my ETX.list.bot post about Gerald North's book >giving the limiting magnitude of a 5" scope as 13.8? Comments? > >Cheers, >EllsMike here: I don't have any Meade stock either.
And more:
From: sherrodc@ipa.net (Clay Sherrod) Ells - thanks again! I have found listed star magnitude discrepancies in virtually every major star catalog and atlas available; that is not to say that you are not glimpsing stars at magnitude 13.7 at that altitude! Above 6,000 feet, you can reach a naked eye limit of around 7.1, so your figure is not off the wall. When you first mentioned the 13.8 in you last post I was thinking in terms of normal conditions (like I have here in Arkansas! Also, you are right about the misnomer on the Pleiades. Regarding the large dob and deep sky; there is no question that a larger and faster telescope with good optics will reveal fainter objects brighter and usually with better resolution than the ETX 125; but when I look at the total package (computer, mount, portability, powered, contrast and magnification, etc.) I still like the 5"; in an ideal world, we would all have one of each to use for every specific object out there. Actually, on my pier the layout is the most practical; the wedge plate assembly is not so long to interfere when looking overhead in polar; keep in mind there is nothing mounted on the north end when in that mode; it actually takes up less protruding space to the north than the Meade wedge for the #887 tripod. Thanks for the comments on the editorial; there is a common thread among those of us who - for whatever reason - love the stars. Your adversity you mentioned help you to "bond" to the scope...."by golly it's not going to get the best of ME!" That's what makes it fun. Clear skies and bright comets - Clay Sherrod -----Original Message----- >Clay, > >Sure appears as though you are having a great time with your >"retirement", and looks like the ETX-125 is only a small but significant >part of that. As always, I greatly appreciated your posts and comments, >especially thinking that truly satisfied ETX-125 users are all too >rare. My ETX became a part of me after it crashed to the ground and I >reassembled it from over forty pieces. My experience with other scopes >is quite limited but this one has brought out a lifelong pent-up >interest in astronomy, as partially chronicled on Weasner's pages over >the last 15 months. Few comments on your recent posts: > >1. I have seen stars down to 13.7 mag with my 125, according to the >Hubble Guide Star Catalog. Surprised you didn't report dimmer than >12.7. I am at 5300 ft ASL. Could that make the difference? > >2. Pleiades is misidentified in your complete review on Weasner as M42. > >3. Having never before used a scope larger or better than the ETX-125, >I had developed "aperture envy" after having considerable problems >finding my last Messier object, M74, in the 125. I recently borrowed an >apparently very well built amateur 10" Dob from the local club and >compared nearly equal magnification views side-by-side on a couple >nights. There was a very noticeable improvement in every view in the >Dob. From double stars, to the moon, to the planets, to nebula, to >galaxies, to you name it. However, on brighter objects the improvement >was minor and the hassle of finding and tracking with the Dob mostly >depleted my envy of that solution. But, I must say the improved views >of the all galaxies were far superior. Nonetheless, I did determine >that my next upgrade in scopes, finances permitting, has to be a major >one since just going for large aperture or a small increment in aperture >with all the bells and whistles probably isn't worth the effort. > >4. I wonder if your PIER might not be more serviceable if the Alt/Azi >and Polar positions were reversed. Seems like near-zenith or >north-of-zenith objects in the polar mode might result in awkward head >positions > >5. Very nice editorial. You hit some nerves there. > >Starry nights, >Ells
Subject: chinese ETX tripod Sent: Saturday, February 3, 2001 04:49:04 From: JUAN.MARIN.GOME@terra.es (Juan Marin Gomez) (Sorry for my english!) I have an ETX 125 EC , and in the past I have problems with the original Meade ETX tripod. With a cost of a half, I adapted a chinese altazimutal tripod. I send you pictures of this in altazimutal mode and ecuatorial (polar ) mode. I'm a fanatic of your page. Yours. Juan Ignacio JUAN.MARIN.GOME@terra.es
Subject: Re: EXT-125 questions
Sent: Friday, February 2, 2001 15:01:46
From: sherrodc@ipa.net (Clay Sherrod)
To: Paul St. Amand
Paul, yes I have the time to try to help and I hope I can do so.
Your experiences are not necessarily uncommon; indeed, they sound very
much like mine when I first got my ETX 125 last year. I think I have a
handle on a couple of things, and there are some issues that maybe we
need to communicate further.
FIRST, I need to know a couple of things to help you completely:
a) Are you using the Autostar, or the Standard Electronic control
unit? Since you mention that you are using the scope in Polar with
the table top tripod, I assume you are not using Autostar.
b) Did you get the telescope from a reputable Meade dealer who can
take it back and EXCHANGE IMMEDIATELY for another unit if we decide
this one is not working properly? (to send back to Meade right now
is going to take quite some time).
c) Do you feel comfortable working on the INSIDE of the telescope's
mount if so needed? Keep in mind that this might affect the
warranty, but there are some things that might be necessary that are
NOT difficult to do.
Now, let's answer (or at least tackle) your questions:
1) Slop when Slewing - this is, unfortunately, common for nearly all GO
TO telescopes, not just Meade. This is caused by "gear backlash" in
which the gears (the worm gear and the worm wheel, or "drive gear") have
been moving (thus torqued) in ONE direction and you can imagine them
being in tight fitting, tooth-to-tooth; NOW, when you oppose that
direction to slew, there is a moment of time in which the gears must
turn to re-establish contact with one-another on the OPPOSITE side of
the "peak-and-valley" of the teeth. If you observing at relatively high
power and are moving at a fast slew speed (you can adjust the speed with
your handbox; always use slowest speed at highest power), the change is
very abrupt and difficult to contend with. Please do this for me: put
your telescope on a bright star (or planet) and choose your HIGHEST
SPEED; with the object centered slew in one direction, stop a moment and
then slew in the other direction. AFTER STOPPING the first time COUNT
the seconds between pressing the slew button (opposite direction) and
the time the image actually begins moving.
Now do the SAME THING at your SLOWEST slew speed; get back to me and let
me know the times of delay. Some delay is common and expected.
2) I have had and used both the ETX 90 and ETX 125 and have not seen an
optically poor one yet; the optics are, in my opinion, the very best. I
suspect that there may be THREE CULPRITS hurting your image:
a) Seeing conditions - the clearest nights up there in Kansas,
combined with the extreme cold you have had, also make for the WORST
nights for high-power planetary viewing; you should easily see
Cassini's and detail on Jupiter; Jupiter, by the way, is NOT as easy
a target as most suggest. Check out "Observing Jupiter" Tech tip on
Mike W's ETX site that I wrote concerning the use of power and
filters. I believe that your cool-down time is adequate, but winter
months in your part of the country are the worst for planets.
b) Your eyepiece - this could be the biggest problem you have. I
do not like, nor have I EVER seen acceptable images in Zoom
eyepieces, no matter what brand or how much they cost. I know you
paid a lot for your zoom, but you would have been much better off
with three good quality Meade super plossls. The added number of
elements in a zoom, combined with their need for absolutely perfect
alignment makes them less than satisfactory for serious viewing.
c) The shakes - a lot, if not most, of your problems at high power
are probably related to the table top tripod; even with the ETX 90,
the legs are not sufficient to dampen vibrations; you are right, it
will vibrate you all the way to quitting astronomy; perhaps you can
come up with some kind of portable pier or tripod (I think Meade has
the #883 on sale right now).
Concerning the shakes and another question you posed is the problem with
focusing without vibration. Unfortunately in the ETX scopes, there is
no such thing when you focus by hand; the knob and scope are so
confined, it is impossible to not introduce vibrations. I am using the
Meade Electric focuser which has been an absolute Godsend; everyone who
opts for an alternative focuser method has suddenly risen from the
ashes! Think about making an investment in one....if you do no know of
a reputable dealer who can sell items at a discount, please let me know
and I will recommend several. Regarding the flexible focus cable, stop
and think about that one....when you focus, the cable is curved, right?
You get your focus just right and let go of the cable; what does it do?
Finds gravity and rotates out of the curve, hence turning the focus knob
and changing the focus. I have tested all of them and cannot use them.
3) Focuser coming off - granted, it is not the best thing to have done,
but it does happen; you certainly took the right approach in
re-inserting it properly. I doubt seriously that ANY change was made
nor problem incurred from that. More likely would be for the primary
mirror (that's what the knob moves when focusing) to reach its limit and
lock up or shift, but that is something you would already know about.
So rest easy on that one.
Be sure to look under "Tech Tips" on the ETX site and find the "ETX
Tune-Up" posting that was contributed by Scopetronixs; it is excellent,
and can tell you why you might be experiencing play in either axis and
what YOU may be able to do about it. Before you attempt, get in touch
with me and let's talk you through it; a little more info might reveal
that your scope is really okay. If your RA drive is REALLY experiencing
long delays and slop, there is a possibility that one of the set screws
on a certain nylon gear may be slipping; this is not common, but several
people have posted this problem on the site.
In addition, take careful note on the "ETX Tune-Up" posting about
"loading" the drive gears; this pre-torques the gear (either axis) to
reduce gear-to-gear play.
Let me know on those issues I noted and we can take it further; I
really believe your scope is okay....the sky conditions are not the
best, and you may not have chosen the ideal eyepiece. Let's work on it
and get your scope in shape.
I would go ahead and contact whoever you purchased the scope from and
let them know NOW that you may have some serious problems. That way,
the stage is set for an exchange. Don't wait too long.
Get back in touch, and thanks for writing.
P. Clay Sherrod
-----Original Message-----
From: pst
To: Clay Sherrod
Clay,
I saw from your posts on Mike's ETX site that you seem to know your
ETX. I hope you can answer a few questions for me. If you don't have
the time, thanks anyway!
I just got an ETX-125. It is really cold here in Kansas, so my
experience with the scope is limited to 3 frigid hours of viewing
(scope was cooled outside for 2 hours before I started viewing). So
far I am disappointed.
First, my scope seems to have a lot of slop in the slewing,
especially when I first slew in an opposite direction (I have only
tried Polar alignment so far). There is a pause as the motor wines,
then the scope jumps. Yes, I did first calibrate the drives and then
train the motors. How normal is this?
Second, how do evaluate the quality of the optics? Previously I was
using a 90mm diameter refractor of extremely low quality (department
store toy); yet, the views from that scope seem to be about as good
as those of the ETX-125. So far, I can not see any division in the
rings of Saturn and views of Jupiter only have 2 faint bands, no
clear views of other clouds. Also, the edge of the disk of the
planets is not all that crisp. I realize that I have had limited
time to judge this scope, but I was expecting much more.
Incidentally, I am using the Meade 8-24mm zoom.
Third, with the table top tripod on a firm concrete driveway, there
is way too much movement of the image. It really jumps and jiggles.
Also, the mirror seems to have a lot of play when touching the focus
knob (I have a flex-focus knob).
Fourth, the sidereal tracking drive makes a fairly high-pitched
sound (while tracking - slewing is much louder, but not
high-pitched). It is somewhat irritating. How normal is this?
Finally, when I first got the scope I turned the focus too far and
the knob seemed to come unscrewed from the mechanism. I tilted the
tube straight up and turned until it started working again, but I
don't know if that affected the scope in any way.
I am really considering sending the scope back to meade for them to
look at. Do you have any suggestions, ideas?
Thanks,
Paul
Mike here: Paul said:
And from Clay:
That is a very good point, and a potential problem that I missed altogether. In the wintertime, all factors concerning differential heating are critical, and certainly a 5-6" slab of concrete can hold head indefinitely. I think a microwave cart might be a bit small for the ETX 125; it would be very easy to construct a sturdy wooden platform out of 2 x 4's and a piece of heavy plywood for a top. If sturdy enough hinges were used, it could even fold up nicely to flat and perhaps even have a very useful handle on one side to carry with! CLAYAnd more of this conversation:
From: sherrodc@ipa.net (Clay Sherrod)
Paul, glad you responded. Let's see if we can get this scope going!
1) In using Autostar, I have found that the effect of time-lapse during
reversal (backlash reverse) is exaggerated over what you will experience
in the standard hand controller that comes with the ETX 125; for that
very reason, when I plan to do strictly one-object type observing (i.e.,
watching the transit of the GRS or the moons of Jupiter), I always opt
only for the standard hand controller; you will see the lapse time (even
as you have noted from your own timings) is considerably better at
slower slews.
I have found that Polar mode is by far better in accuracy of both GO TO
and actual sidereal tracking once found at high power. As I have
mentioned in my field review, I was able to track Saturn at 310x for 40
MINUTES after carefully aligning in my test. My time in Alt-Az has
NEVER been that good, maximum of 10-12 minutes; keep in mind the Alt-Az
must stair-step to track sidereally, which introduces (by nature of the
motion) a incredibly brief stop at each right angle increment which must
at some point be made up for. This results in: 1) slightly less
accuracy and more dependability on EXACT alignment; and, 2) a
rougher-driving mechanism since two motors are opposing one-another.
2) Shutan is a great dealer; based on some of your newest comments, I
think you should exchange the telescope, and I will explain my reasoning
in a minute. Typically (and those who know me will - at this point - be
saying "WHAT!") I will stick to what I have until my resourcefullness is
exhausted but you appear to have one problem that you will not be able
to fix. Shutan (ask for Bob Shutan) is super to do business with and
about as honest and customer-friendly as they come.
3) I, at this point, think you have ever reason to exchange the scope
and NOT return to Meade; yours has problems that were shipped to you
with the scope.
4) Right now, stay away from trying to fix the scope....if I am clear
on what you have told me, and I will ask for a clarification.
5) Slew Slop - your fastest slewing speed delay is VERY common, and
I'll bet that the middle is about the same rate (less than one second).
At 73x, it is difficult to see the very slow slewing, as this is for
high power correction only; it takes a while before the human eye
perceives minute motion at low powers. At rate "2", a six second delay
is also about normal if reversing the motor from its previous direction,
provided that the motion seems delayed for that length ONLY at low
powers; I'll be at higher mags. you will see the motion a bit sooner.
Your timing is about similar to mine I believe.
6) Seeing conditions - I am writing a Tech Tip right now for Weasner's
ETX site regarding evaluating "seeing" conditions. It is a very
important factor and one not readily understood. Briefly, let me tell
you this:
a) the coldest, deepest-clear nights are typically the worst
regarding seeing; this is because the earth's heat from the day is
rapidly dissipated into the cooler night air, causing convention
currents which rapidly rise upward, like seeing the heat from a
desert highway that appears like currents of water.
b) first way to check your seeing: if the stars twinkle overhead,
keep your powers BELOW 100x, regardless of telescope size; if they
twinkle on the horizon, but appear steady overhead, powers of 25x
per inch aperture are good; no twinkling at all - have at it!
c) second, and best way, of checking your seeing is to take a
bright star about half-way from any horizon (away from rooftops and
asphalt) to overhead and center in your telescope at your 73x or
about 100x and then DE-FOCUS the image until it makes a nice disk of
white with a dark silhouette of your secondary mirror in the center,
like a donut. Look at the bright disk; if the disk remains fairly
uniform without distortion or movement, like ripples, your seeing is
excellent for higher power use; if, on the other hand, the disk
appears to oscillate or change uniformity then, once again, limit
your observing on that night to around 100x or less for ANY
telescope.
If the seeing is good, then everything - your planets, double star
resolution, limiting magnitudes of stars and Cassini's division are all
equally attainable. (See my Field Test of the ETX 125 in Mike W's site
for a complete review of what you should expect to see under
near-PERFECT conditions.
7) Power - planetary observing should be done with a MINIMUM of about
150x for any scope. Optimum for your telescope (50 power per inch
aperture) is about 250x to 300x; on perfect nights (see #6 b-c, above)
370x and above are possible. I can routinely see Cassini's division with
the 26mm PLUS BARLOW. (about 156x). In my 26mm alone, it is very
difficult and only sometimes. Same thing applies to Jupiter and maximum
resolution of double stars. The 26mm alone is my favorite eyepiece for
deep sky.
I prefer the combination of eyepiece + barlow; not only does it DOUBLE
the number of power options you have with limited numbers of eyepieces,
but it also DOUBLES the power. The zoom eyepiece has a couple more
elements than the combo, but the real difference is axial alignment of
each element, particularly since it is necessary for several of the
elements of the zoom to rotate relative to fixed ones. I have not seen
a zoom I would use. For planetary observation I always use the 26mm +
barlow (156x) and the 15.5mm + barlow (310x) which gives me spectacular
views; in addition to Cassini's, Encke's division is very obvious at
310x
8) Mounting vs. vibration - opt for the tripod before the electric
focuser, but you really need to be thinking about both (in an ideal
world, right?). The tripod is the ONLY way to assure happiness with
such a large scope. It DOES NOT matter from a stability standpoint
whether you align Polar or Alt Az. I have told you I prefer Polar and I
believe that placing the center of gravity OFF azimuth (RA) axis and
essentially loading (torqueing) it by Polar aligning creates a much more
firm base in which vibrations dampen quicker.
All of the Meade tripods (or any brand) can be used in BOTH modes;
although expensive, I have found that the heavy-duty #887 tripod is
PERFECT for the ETX 125.
NOW, to your biggest problem and one which you barely even mentioned in
passing: image shift during focus. If you are having to "...focus in
one direction only," you have a serious deficiency and one that was VERY
common in the earlier models of the ETX 125 which you may have; they are
not serialized, so there is no way of telling on your end. The focus
shift is not a mere inconvenience, but rather, it is a symptom of an
affliction far worse. Just like you zoom eyepiece where the axial
element alignment is critical, so is it on the
primary-to-secondary-to-eyepiece-to-observer alignment overall. A lot
of people talk of image shift as if it was a wart; bothersome, but no
harm. Not the case. If your image is shifting (your primarly is
oscillating relative to the secondary as it slides in and out) your
axial alignment, even though there is no actual rotation, is offset by
the same degree as the image you see.
I suspect that part of your optical performance issue MAY be well
correlated to the image shift if the motion is as perceptible and your
are prone to "...focus in one direction only." That sounds like a
pretty good image shift to me, one which certainly cause degradation of
the image in a hurry; it also can explain why focusing CANNOT be
achieved in one direction but CAN in the other, as the alignment
mirror-to-mirror is closer at one position than in the other.
If the shift is caused by pressure against the primary mirror (which
does happen), the slight torque can actually disfigure during focusing
the primary to the point where that position of the mirror's surface no
longer corresponds to the overall wavelength correction of the overall
system.
Let me know about that shift ASAP. Right now, gut feeling (if the shift
is as bad as it sounds, and it HAS been in many cases in the past) is
that you should ask for an exchange. Meade WILL fix the scope, but I
would call and discuss about turnaround prior to sending and get a
reasonable assurance of return. I also would ask them to tweek the RA
drive to take out as much of the delay as possible.
Exchange or repair? That is your call. If it were my scope - and,
again, I am well-known for my "stick-to-it-ness" - I would ask for an
exchange.
I hope this helps. Normally my news is more encouraging to folks with
my "...we have problems so that we can dream up solutions" philosophy.
However, when I read your comments about such an image shift I knew
immediately what I would do.
Best of luck and let me know of your decision; certainly keep in touch
and update with progress.
P. Clay Sherrod
Arkansas Sky Observatory
-----Original Message-----
Clay, I can't thank you enough for your willingness to share your
time and expertise with me, but THANKS!
Paul
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