ETX-90EC USER FEEDBACK - SEPTEMBER 1999
This page is for user comments and information specific to the Meade ETX-90EC. Accessories and Feedback items appropriate to both the original ETX model, the ETX-90EC, and the ETX-125EC are posted on other pages as appropriate. 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.
Weasner Experiences the ETX-90EC! (7/31/99)
Polar Alignment Technique (3/10/99)
Sky & Telescope ETX-90EC review (4/30/99)
ETX-90EC Press Release (1/28/99)
ETX-90EC Accessories (1/28/99)
Subject: ETX-90EC Sent: Wednesday, September 29, 1999 11:58:57 From: email@example.com (Dale Walker) Thank you for your very helpful web site. It gave me a lot of understanding before I purchased an ETX for my wife's birthday. I waited for the 125 to come out. Played with one at the store, hefted it about and then decided on the 90. Reason, scared of the problems with the 125, but mostly the 90 is much more portable. If its a two hand carry and won't fit under an airline seat, then I might as well get something really big. If we have enough fun with this one and decide to get serious, then we will do just that and still keep the portable 90. The scope is beautiful, as we all know, and the image is just as wonderful. My timing was bad, however. I think that the 125 problems have spilled over into the 90. I had to exchange the thing four times. Declination Knob first, then the computer, then something big came loose in the base (which went clunk, clunk when I tipped the unit while the scope free-wheeled) then another computer. And now it all seems to work. The GOTO usually gets things almost in the eyepiece. Optics are great. Tracking is good enough for observing though certainly not good enough for long exposure photography. Curiously the GOTO totally missed a 3/4 moon while it found planets and stars reliably. I've got the download cable so I will soon try updating the software. Last night we had some real fun. With my laptop, a $79 QuickCam, and a big rubberband, we got some CCD images. No modification to anything. The ball like QuickCam fits snugly into the rubber eyepiece. The rubber band goes neatly under the back of the scope. We didn't get the focusing very tight, but we got moon pictures first time with everything set on automatic ! The finder scope is pretty much unusable. Meade has got to figure this is a marketing ploy to generate an extra sale as everyone pays $50 for a right angle finder. Well, I'll show them and buy a 1x Celestron or Rigel or something. So, am I happy?? You bet! This is marvelous technology for the price. Maybe most won't be so unlucky with the quality control. I've also recently played with a Nextstar 5 a bit. Now there is a real telescope, but it won't fit under an airplane seat, and it probably isn't as good as a terrestrial scope. Clear skies to y'all, Dale Walker
Subject: New ETX90/EC and DEC problems Sent: Tuesday, September 28, 1999 16:39:47 From: firstname.lastname@example.org (Gavin Scott) I spent the last few days up at Lake Tahoe, and the weather has been so perfect, and the skys so clear, that I broke down and acquired an ETX 90/EC and Autostar at the Natural Wonders store in Reno yesterday. The Autostar had 1.1j in it. Unfortunately, the DEC axis exhibited about 12 degrees of slop with the DEC lock tightened, and the drive would run but appeared to be incapable of moving the scope up or down much at all. Drat. A dud. The ETX came in the original unopened Meade shipping box and had been shipped directly to the store from Meade, so I was pretty sure I was getting a brand new one rather than a return. The Autostar was also clearly unopened. So I spent the evening happily observing Jupiter and Saturn (which looked absolutely awesome, so the optics at least seem to be ok). This morning, rather than hoof it back to Reno to return (or exchange, but I think it had been the only one they had in stock), I decided to give Meade a call and see if their support people could help me find a solution. I spoke to Ed Parkyn, who thought it might be related to the known problem with the bad plastic used in some of the right hand tube adapter units, and offered to overnight a replacement tube adapter to me, which I took him up on. I only had to wait about 5 minutes on hold before Ed answered. After lunch and a trip to Ace Hardware to acquire the magic 7/64 hex wrench, I removed the OTA from the mount and examined the tube adapter. The tube adapter looked fine, so I removed the six screws holding the cover on the right hand fork and removed it to get a look at the declination assembly. The heart of the dec system is an assembly consisting of a metal bracket holding a brass(?) worm drive screw with a locktite'ed nut on one end and a nylon gear with a ~3/4" shaft attached to the other. Each end of the brass shaft has a set of washers on it designed to eliminate lateral play in the shaft while still allowing it to rotate. This assembly is held to the fork arm with three screws and lockwashers. Operating the dec motor with the manual hand control, it became clear that while the motor was driving the nylon gear just fine, the brass shaft with the worm drive was not turning with it, but was in fact screwing and unscrewing (aparently) from the nylon gear's shaft! At this point I called Meade back, and Ed answered the phone immediately. I explained what I had discovered, and he looked at his diagrams to try to determine how the nylon gear actually attaches to the brass shaft, since neither of us could believe that anyone would actuall design the things to screw together. From the diagram he couldn't tell exactly what was going on, so he went out to the assembly line to look at one in person and then called me back. We then discovered that I could remove the worm drive assembly by loosening the three scres holding it, then lostening the two screws on the motor assembly to the upper left and lower right of the motor (the ones which have a white nylon washer on top of a black o-ring) to allow the motor assembly to pivot out a bit so that the nylon gear on the end of the worm drive could pull out of the motor assembly. This exposed the fact that the nylon gear actually ataches to the brass shaft via a 3/32 hex screw that passes through the gear and threads into the end of the brass shaft. It was this screw that was loose, which prevented the gear from driving the shaft, and was causing the brass shaft to move up and down as it "screwed" on and off the screw as the gear turned. Aha! Problem solved? Well, not quite. It appears that the worm drive assembly was put together with the screw not completely tight, so that if I tighened the screw completely, the worm drive shaft could no longer rotate because everything was bound together to tightly at that point. So it looks like a solution will either be to losten the locknut at the top of the worm drive shaft by 1/2 turn or so (but this may be problematic because the nut is locktite'ed in place, and coated with grease, so if I manage to turn it at all, it's likely to keep turning :-), or possbly to substitute a slightly smaller washer for one of those making up the spacing in the brass shaft. I'll try some experiments later. Ed is going to overnight a replacement worm drive assembly to me tomorrow, so if I can't repair the current one I should have a replacement Thursday or so. The current drive assembly has a small paper label with a date on it (from May, close to the workorder dates on the shipping carton) and what look like the initials L.R., probably the one responsible for mis-assembling the thing in the first place. Ed went off to have a word with him :-) So while my new toy still isn't up any running in GOTO mode yet (making a cable to upgrade the Autostar will probably be my next project), it sounds as though I'll be able to fix it without having to return this one and track down a replacement. I can't say enough good things about the service I've gotten so far from Ed at Meade's tech support. He and I now both know a lot more about how the declination drive in a 90EC works too! I'll send you an update later to let you know how things turn out. GavinAdded later:
Well, here's an update. I took a couple blocks of steel and placed the slightly conical washer from above the nylon gear at the bottom end of the dec screw drive assembly (someone told me what these are called, but I've forgotten) between them and squeezed the whole mess gently with a c-clamp, resulting in a decrease in "height" of the washer by about 1/3. I then reassembled the declination drive screw assembly, and found that the newly flattened washer was now the perfect size, and the drive screw turns freely with no up/down play at all. So I didn't have to mess with the lock nut on the top of the drive assembly at all. I reassembled the rest of the scope, then took a brief jaunt over to Radio Shack to pick up the bits to build a PC cable for the Autostar (25 foot phone handset extension, 9-pin D female plug, etc.), slammed them together and found that it worked the first time(!), downloaded 1.3b from Meade and successfully flashed the Autostar with it. I then trained the drives and carried the ETX outside onto a balcony. My first easy align didn't result in great pointing (I think I centered on the wrong "second" star). After manually slewing to look at Jupiter and Saturn for a while, I tried another easy align. This time there was no tree in the way of my second alignment star, and after completing the alignment, I was able to goto Jupiter then Saturn, then M2, then M31, then the double cluster, then M32, and each time the target was planted very close to the center of the 26mm eyepiece!! Oooooh. Ahhhhh. I then proceeded to try for several other "tour" objects, but the next several were behind the house, resulting in the scope making a few long trips back and forth. Afther this I told it to go back to Jupiter and it missed it by probably 10-15 degrees (mostly in Az.) for some reason. Anyway, I'm pretty jazzed at the moment. The ETX has gone from being DOA to having as good goto performance as I've heard of so far. My luck has clearly taken a turn for the better today :-) Let's see, now I need to buy a few hunderd dollars worth of eyepieces, a case and possibly a tripod, and I'll be set. Too bad the skies back home (Bay Area) aren't like the skies here at Lake Tahoe.And a further update:
UPS showed up at 10:30 with the first of the free overnight shipments from Meade, specifically the spare right side tube adapter that Ed at Meade first thought might be the problem.
Subject: strange buzz Sent: Wednesday, September 22, 1999 17:23:07 From: Robbi228@aol.com First let me say I love your site, there is so much great information. I just received my new ETX-90EC today and am trying to get familiar with it. I have a question though, when I turn on the scope with the hand controller plugged in, I push a button and it does its initial movement. After this movement stops the scope begins to make a strange buzzing sound coming from the base. When I push the right or left button the noise stops but then resumes a few seconds after it stops. Any ideas, or is this normal? Thanks so much for your time! RobMike here: This sounds like the RA tracking motor. This motor runs to compensate for the earth's rotation.
Subject: General ETX90/EC Sent: Friday, September 10, 1999 23:12:38 From: email@example.com (John Chalfen) I've had my ETX since June, went thru the same hassles most did. The Autostar problems and dec knob, failure loose screws.....Anyone else have the autostar decide to slew backwards? Anyways, I had been using an lx-200 for a couple of months and let the ETX be. I did all the updates for the autostar and took it out tonight. It behaved perfectly. Put everything right in the finder, (and eyepiece), tracked both jupiter and saturn for an extended time (longer than 10 minutes) and kept them centered. Now I think I have the portable scope that I can travel with. Just took a little time and patience and some work, but I think that the ETX/EC is going to be pretty good travelling partner. I'll keep using the lx-200 for taking pictures though, the ETX just can't handle the camera. Bummer. -------------------------------------------------- TIA and TTFN firstname.lastname@example.org email@example.com (I know...I know...)
Subject: Polarity of ETX90-EC Sent: Wednesday, September 8, 1999 11:06:58 From: Stantastic@aol.com I saw this in the User Feedback section, but you didn't supply an answer, so I thought I would just in case. Alain Gliksman asked about the polarity for the power supply to the ETX. The CENTER PIN (normally called the "tip") is POSITIVE, and the OUTER RING is NEGATIVE. I've run off both an AC wall adapter and the cigarette lighter adapter in the car and both work fine (much better than batteries!!!) Stan Glaser firstname.lastname@example.org P.S. -- The "two weeks" promise for the Macintosh software from Meade's Vice-President ("Coming Soon!!" on Meade's web site) has since come and gone!! Sigh!! P.P.S. -- I have downloaded the latest ROMs (1.3b) from Meade's Web Site, along with the "beta" pre-release update software (X1.2002) and using Virtual PC on my Mac got them to work. I'm still assuming that the ONLY items that can be downloaded to the Autostar Controller is the Autostar and DBase ROM's, not any other files (such as Asteroids, Comets, Satellites, etc.). But the beta software will read that info currently in the Autostar, allows you to edit it onscreen (or add a new object), and then will download that new info into the controller. I tried doing JUST that by itself (after I had already updated the ROMs as a separate exercise) and it left me hanging without a way out (the "Done" button exits the Autostar Update software but the hand controller is still left in the download mode with no way to exit.) I ended up turning off the power to the ETX, turning it back on, and found that my edits actually had taken place. I'm forwarding my findings to Meade today. It's all beta, so it's "understandable" -- hope it's fixed in the future. I also noticed that while I had control of the scope using Cassady & Greene's Info-Genie plugin in the Starry Night Deluxe software from Sienna (it uses LX-200 commands compatible with the ETX) in the 1.2g version of the Autostar software, I seem to have lost slewing capability in the 1.3b version (although the "follow" command still works!!). Strange indeed.
Subject: ETX 90 "Vibration" Sent: Tuesday, September 7, 1999 23:50:46 From: email@example.com (Steve Reed) I've had an ETX-90EC for some time and think it's a great little scope, especially for the money. After reading the recent Sky and Telescope review on the ETX-125, however, one of the comments the reviewer made really hit home. Until then I'd been annoyed with what I though was "my" little problem, but hadn't really thought too much about it since I only occasionally view double stars. The reviewer mentioned "motor vibrations" that made it impossible to split the Double-Double (Epsilon-Lyra). I had viewed Epsilon-Lyra just 2 nights before, and had the same problem with my ETX-90. At high power, the stars looked more like little lines, in fact. The odd part is that some months ago I had no trouble splitting the star, Castor - and pretty cleanly at that - which is a closer double than Epsilon-Lyra's component stars. It doesn't seem to make a difference whether I use Alt-Az mode or Polar mode when observing. Why should this be? Obviously, seeing conditions can play a part in this, but I've tried it on several nights and get the same result. The only real difference (other than seeing, possibly, but in my experience that doesn't turn stars into lines) between the viewing sessions is that I've updated the Autostar software to a newer version (1.2g) since making the original Castor observations. Since the software drives the motors, is it possible that a software change could cause something like this? I'm very curious to know if you or other visitors to your site have noticed a similar problem. Thanks.Mike here: I doubt that the s/w is causing "lines" or star trails. It sounds like something might be binding. There is some hesitation with the ETX-90EC RA drive unlike with the ETX-90RA RA drive that ran continuously. But that does not sound like what you are seeing.
Subject: ETX 90EC User Report Sent: Monday, September 6, 1999 00:30:09 From: firstname.lastname@example.org (Gregory David Stempel) I have now owned my ETX 90ec for what maybe two months. I have used it everynight that has been clear. Here in the NW that's not too many sometimes. I can now set up the ETX and Autostar with confidence and have figured out a few things that may help others. The ETX will place targets in the EP with regularity. Two targets I always check when I fist begin a nights viewing is Albeiro and M57 (The Ring Nebula), if my set up went well then these two items will be in the ep every time. First, as most probably know by now, set up (including motor alignment) is very critical. If this is done right and extremely accurately you will enjoy your evening. I did not purchase the tripod, these are always far to weak exhibiting lots of flexure. Second metals transmit vibration, where wood will dampen vibratory problems very quickly. So, I built a wooden pier. A flat base, four sides and a top. Then I filled this with sand. Now I have a very cheap, solid platform to place the ETX. I place a quality compass on the top of the pier aligning it with magnetic north. This allow me to draw a dark, heavy line pointing to true north on the top of the pier. When I place the ETX on the pier, I align the boxed shaped area (were the power on led and switch, handbox connector, etc. are located) along this line by looking down from the top of the scope. I spend several minutes making sure this alignment is tack on! Next I home the scope by placing the dec arrow on the fork arm, dead over the power-on led (with it on) again, taking as much time as necessary to make sure this is tack on. Finally, I zero (leveling) out my ota using one of those bubble levels that conturtion people use to hang on line stretched out to mark where a fence line or cement pad would be placed. The reason is it is shaped with flat edges, and will sit on the tube for a perfect level. I have great success with these efforts either with an easy align or two star alignment. One other item I tend to do carefully is aligning my motors. I have noticed that when I do an az align the alt align, the az seems off just a tad. So I always do a second az align. These alignments need to be done (in my opinion) after each new upgrade from the Meade Site. Since I have learned to take the hard road in homing and aligning the ETX, not doing it in hurry, paying special attention to the proceedures, I have found and targeted dozens of objects in my skys. NGC 869 shows up in the ep. M13 is in the ep. M29, M31, M3 all show up in my ep. Talk about a joy. One last comment, in Synch mode, the best approach I have found, is when the Autostar beeps, look in the ep, and hit/hold enter until the synch mode is on then slew to center the target. If the ETX moves a little after synching, just slew the target back in place. I have put M13 in my ep, and went upstairs to look at star charts, visit this site, etc., for an hour and then went out to find M13 still almost dead on where I left it. Really quite amazing. Hope these tips help to fine tune your nights. Visit Oceanside Telescope and Camera, they will help you through the problems. They sent me three Autostars until I got one that worked. Take care out there, Gregory david Stempel FIREFRAME
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