|
Last updated: 30 November 2006 |
This page is for user comments and information of a general nature or items applicable to all ETX and DS models. Comments on accessories and feedback items appropriate to other ETX and DS 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: EXT Amateur Astronomer Kit question Sent: Thursday, November 30, 2006 18:26:40 From: jemulkey@bellsouth.net I have a EXT90PE for my 9 year old for Christmas in my closet from optcorp. Are there any accessories you would recommend that are not in the Amateur Astronomer kit to maximize our out of box experience? Thanks, John Mulkey Oxford, MississippiMike here: Well, what you get will depend on your 9 year old (or you) will use the telescope. I'd recommend first learning the telescope and discovering what enjoyment you can get from the telescope. Then once you have a better understanding of your child's desires (or your desires) and the capabilities of the ETX-90PE you can decide on how to expand it.
Subject: ETX125 Filter Sent: Thursday, November 30, 2006 13:57:19 From: User721401@aol.com (User721401@aol.com) I was wondering if you can recommend a good filter for the 125PE.. I am interested in trying to reduce some of the pollution. Thanks DanMike here: There are various filters available that may help, depending on the source of the light pollution and the objects to be observed. See the Accessory Reviews: Filters page for comments on skyglow, light pollution, narrow- and broadband filters.
Subject: Reply to WILLIAM MCKINSTRY on the subject "Meade" Sent: Thursday, November 30, 2006 09:31:01 From: Kim Miau Lee (robin051@gmail.com) Basically, you can buy Meade telescope from US vendors. Meade doesn't officially allow this but many of the Meade owners do this to prevent buying much more expensive scopes. There is advantage buying from the local vendor. Just in case that your scope is faulty, the dealer will send the scope back to US. He can provide you some technical supports too.
Subject: Suggestion For "For Sale Page" Sent: Thursday, November 30, 2006 08:19:57 From: Kim Miau Lee (robin051@gmail.com) I would like to suggest that the sellers or buyers who write to you, state their main items clearly in the subject line. It's more convenient for us to surf through. By the way, your portable observatory looks nice. I am going to make mine with several panels to block the surrounding light to enhance my dark vision. -- -Robin Lee My Astronomy Blog- www.AstronomyNotes.net
Subject: ETX125PE SLEW PROBLEMS Sent: Wednesday, November 29, 2006 05:39:48 From: Mike Edwards (mikee@timberframe.co.uk) Telescope motors do not respond to command from autostar handbox. The wires came loose from the handbox/telescope cable and shorted out at the telescope end. Power supply is 12V DC via a transformer into mains 240V. I fitted a new cable, but the telescope will not move, motors will not run at all. When setting up alignment, handbox display works fine, but the scope don`t slew anywhere! Power supply to scope & handbox seem fine. Any ideas?Mike here: Could you elaborate on the "wires came loose" comment you made. It could be that something was damaged in the circuitry on the board inside the ETX base. That would likely require a repair by Meade.
And:
thanks for swift reply; the wires actually parted company from the male plug that slots into the face board of the telescope base probably causing a short circuit. This more than likely occurred because I let the hand set dangle on the wire, rather than purchasing a proprietary handset holder/carrier. I was subsequently recommended to contact BC&F for advice, as my scope is out of warranty. Steve at BC&F was extemely helpful, and suggested that the circuitry behind the face board of the ETX base was damaged, and that if I sent the scope in, He would look at it for me. I`ll keep you posted of developments.
Subject: overheat while viewing the sun Sent: Tuesday, November 28, 2006 10:04:03 From: John Chase (johnmchase@comcast.net) I recently purchased a Thousand Oaks filter for my refractor and while viewing the sun I got a little warm. Since I am used to wearing heavy coats for night time observing It occurred to me that prolonged sun observing could get uncomfortable pretty fast. I happen to have a survival blanket that is highly reflective on one side only I threw this over my head, with the shinny side out, while observing and there was a noticeable decline in my personal heat absorption. Anyway I saw somewhere, I thought on your site, where someone was having similar heat issues and I figured I would pass this tip along. you can see the blanket if you do an Amazon search with the key words... Emergency survival blanket ps great information in your site thanks for taking the time to provide it John Chase
Subject: Power switch 125etx Sent: Tuesday, November 28, 2006 09:44:12 From: StpFerris@aol.com (StpFerris@aol.com) HI, HAS ANYONE HAD THE PROBLEM OF THE POWER SWITCH, HAVING VERY POOR CONECTIVITY, THAT IS, THE SWITCH SWITCHES ON /OFF. ALL BY ITSELF AND AT TIMES REFUSES TO POWER UP AT ALL. STEVE.GREAT BRITAINMike here: The article "Repairing Battery Cutoff Switch" on the Helpful Information: Telescope Tech Tips page might help.
And:
From: Niall J. Saunders (niall@njs101.com) Hi Steve, I have never had to work on the innards of an ETX125 - I have owned one, but did not get the chance to strip it down. However, if it is anything like the ETX-105, then you are going to find it very difficult to get 'into' the board that hold the power switch. You may be able to 'get at' the connectors at the back of the switch - and make an educated guess as to how to by-pass the switching action (therefore relying on an external disconnect to remove power from the scope). This is something you would have to tackle on your own. Failing that, I would SERIOUSLY suggest that you contact Meade UK and explain your problem to them. You might well be best served by putting the ETX-125 into the back seat of your car and driving to them - at least you don't have as far to go as I would !! I know that I would be able to fix the problem (well, I would be reasonably confident) - but that is only because I have had more than thirty years in the electronics repair world - that said, I could not compete on the commercial charges that Meade UK will levy. Give them a call, and let us know what their answer is. Regards, Niall Saunders Clinterty Observatories Aberdeen, SCOTLAND From: StpFerris@aol.com Sent: 29 November 2006 19:52 To: niall@njs101.com Subject: Power switch fault(ETX125) Hi nial,read your note on the weasner site, and also emailed mike,about a power switch that does not switch on unless rattled and poked about with, Have you had any success in repairing or replacing the actual switch . Regards Steve England (Raining)
Subject: etx-80BB vs etx-90 newbie purchase Sent: Saturday, November 25, 2006 19:12:53 From: Duckyfred (duckyfred@cox.net) I am a newbie looking to purchase my first scope. I am looking at the ETX-80-BB and ETX-90. I would like to eventually use it for photography purposes. Which would you recommend for a beginner? Thanks for any help.Mike here: See my comments on the ETX-90 and ETX-70 (similar to the ETX-80) on the Helpful Information: Buyer/New User Tips page. Also, see the various user reports on the Helpful Information: User Observations page. Depending on your expectations and budget, you may prefer one model over the other. Keep in mind that they are two different telescope designs, delivering different performances.
Subject: Re: etx 125 electric focusser takes off on its own Sent: Thursday, November 23, 2006 13:34:02 From: Chris and Claire Nuttall (c.nuttall@tiscali.co.uk) just a quick note to say thank you i made a cable and updated my autostar, this seems to have solved the focusser problem - i thought i should let you know and then you can pass on the info if someone else has the same problem. Many thanks Crhis nuttall
Subject: Scopetronix Sent: Thursday, November 23, 2006 13:24:48 From: Phil G (cphilg@ix.netcom.com) This is the first I've heard about Scopetronix issues. I was browsing their page today looking at the MaxView adapter to use with my Pentax *istD camera. I have their old MicroStarII drive controller on my ETX-90 RA and love it... I used to e-mail back and forth with Jordan quite a bit tweaking the internals of that thing and I'd hate to think they'd be down for long. Phil G.Mike here: The problems surfaced a few months back. Unless they just got resolved, you may experience difficulties getting products ordered from their Site.
Subject: Updating an ETX-90EC with Autostar Sent: Wednesday, November 22, 2006 21:13:34 From: dsmurphy@optusnet.com.au (dsmurphy@optusnet.com.au) congrats on a great web site. As I am just about to embark on home astronomy and am keenly considering a Meade telescope I expect I may become a regular visitor. It looks to be jam packed with good info. I am considering buying a second-hand ETX-90EC, which I believe to be in good condition, but at the same time like the benefits (especially for the novice) of the Autostar package which comes with the ETX-90AT. Are these two telescopes essentially the same. I know I can purchase the Autostore package at a later date. Are there any electrical and/or mechanical aspects of the 90EC which prevent me from up-specing essentially to a 90AT at a later date by the addition of the Autostar handset? As the ETX-90AT costs a little more than the Minister for War and Finance (my better half) will allow me to spend initially, I am hoping this offers an upgrade path for the 90EC. I have checked your web site FAQs first, but can only see reference to not being able to convert the 90RA to an Autstar model. Whilst the FAQs mention that the only difference between the EC and AT is the Autostore handset and the tripod, a local telescope shop here in Sydney has given me concerns that there may be some compatibility issues. Would appreciate any advise you can provide on this matter. Happy for you to post my question on your site but would you please suppress my email address. Cheers from Down Under Sincerely, DarrenMike here: The EC model is the same as the AT model except that it has a simple handcontroller without GOTO capabilities and no tripod included. The AT model has the AutoStar #497 AND the #884 tripod included. If you do get the EC model you can add the AutoStar at a later date.
Subject: Meade ETX90EC Sent: Wednesday, November 22, 2006 11:47:54 From: Itsonly3inches@aol.com (Itsonly3inches@aol.com) I am looking to select & purchase my first scope. I have been trying to find out without any success what wavefront rating the ETX90EC optics have & I was hoping an enthusiast like yourself would be able to confirm it. Very best regards Ian United KingdomMike here: Meade has not published that info. There is a comment about it on Meade's site at:
And:
A million thanks for your kind reply. However, I had already read those comments which are not really very helpful. If Meade were based in the UK I would phone them, but my phone has international call barring to stop my kids running up massive bills. My quest goes on! Take care Ian
Subject: Fw: Scopetronix visual back Sent: Wednesday, November 22, 2006 00:49:11 From: Stephen Bird (stephen.bird@btconnect.com) This might help whilst Scopetronix is closed. They have all manners of custom built accessories for ETX and other scopes. Regards Stephen Bird ----- Original Message ----- From: Stephen Bird To: p-roy@hotmail.com Sent: Wednesday, November 22, 2006 8:46 AM Subject: Re: Scopetronix visual back Try Astro-Engineering at http://www.astro-engineering.com/, they have various international partners shown on their "where to buy" page, so you should be able to buy what you need. Regards Stephen Bird
Subject: RE: Question re. Meade 125ETX as modified by Wegat Optical Sent: Tuesday, November 21, 2006 06:45:01 From: James, Warren W CIV NAVSTA MAYPORT N5 (warren.w.james@navy.mil) Thanks for your reply, Mike- Looking forward to getting it... Basically am hearing nothing but good about the scope. Now to find some rings... You have an amazing site- definitely reflects an amazing amount of work & dedication on your part. See you're a cat lover as well... Have 8 indoors... Not sure how many outside!!! Wes
Subject: Where to get "Using the Meade ETX-70"? Sent: Monday, November 20, 2006 20:47:57 From: bjopt@bellsouth.net A week or so ago I e-mailed you about a Barlow lens for my 13 year old son. I received my 2x lens from OPT today! I thought it would be great for my avid reader to have a copy of your book with the lens for Christmas. I ordered from Amazon, but today received a refund. Out of Stock. :( Do you have any more copies, or know where I can purchase a copy? Thanks for Your Time, AmandaMike here: NOTE that the book is not specific to the ETX-70. But this past weekend, OPT had copies in the store. (I have a relationship with OPT.)
Subject: Meade Sent: Monday, November 20, 2006 19:38:15 From: WILLIAM MCKINSTRY (william.mckinstry1@btinternet.com) I am new to Astronomy, but i wanted to progress a bit, as i am restricted by my present telescope and also being new, i am not sure if i am looking at the star that i want to. I found your website and read your reports on the ETX-125, i have found them a great help in helping me make a decision in the next telescope i should get,i read your reports dated 4/3/2000 in the Buyer/new user tips page on the tests you carried out and the continuous questions asked by owners. So i am just thanking you for the information you provide William Mckinstry PS. I live in the UK (Northern Ireland) so there is a big price difference over here, the 125 is $600 more expensive over here, i was also interested in the LX200R 8", it is $4000 over here at the exchange rate, thats nearly double the US price. This was also a help factor in going for the 125..lol
Subject: Scopetronix visual back Sent: Monday, November 20, 2006 07:35:11 From: Patrick Roy (p-roy@hotmail.com) we keep on hearing that Scopetronix is close, do you know if it is true or not. I send them an e-mail and never got an answer. If this is really the case do you, or anybody else, might know were I could find a Scopetronix visual back . Thanks, Patrick, MontrealMike here: Yes, Scopetronix is undergoing difficulties. We all hope they return. Until then you will have to just check around for dealers of their products.
Subject: Question re. Meade 125ETX as modified by Wegat Optical Sent: Monday, November 20, 2006 07:04:06 From: James, Warren W CIV NAVSTA MAYPORT N5 (warren.w.james@navy.mil) I have a question regarding a scope I just purchased from AstroMart It is a Meade ETX-125 as modified by Wegat Optical. It has a heavy solid anodized aluminum backplate with standard Schmidt-cassegrain threads, and an aluminum threaded lens cover. Focuser upgraded, etc. It was apparently used for Laser research- the only problem I see using it for astronomical use is the fact the corrector lens apparently is not coated. (I have not received it yet, just going from research I've tried to do on it) I didn't really realize this when I bought it, and realize it may be a major issue for astronomy. My question is- would it be possible to get a new coated (regular or- preferably UHTC) corrector or corrector/mirror set from Meade as required to replace the uncoated corrector? I realize this may be a very expensive way to end up with a good astronomical scope, but I really would love to have the improved mechanics of the Wegat modified mechanics. I purchased it as an OTA, I plan on using it on my existing mounts, will have to locate a set of rings for it. Just trying to determine if I bought myself a "white elephant"! Thanks in advance for your time- Kindest regards, Wes James Atlantic Beach, FLMike here: Yes, they were special purpose telescopes. If you search the Site for "white tube" you will get lots of hits. As to getting a corrector plate from Meade, not likely. The optics would have to be collimated. I don't know if the corrector lens is different from the standard ETX-125 but if not and you still want to try to replace the lens you could look for a "damaged" ETX-125 online and as long as the corrector lens isn't the damaged part you might be OK.
Subject: OPT Star Party Sent: Sunday, November 19, 2006 13:48:08 From: Don (donmcclelland@adelphia.net) Congratulations on the 10th Anniversary of you site and also on your award from OPT. I wanted to get your opinion on piggybacking the PST on an ETX. I have the ETX-125EC and was wondering if the weight might be too much for the Dec. motor? Obviously your RA motor could handle it but in Alt/Az mode I'm not sure. Don McClellandMike here: Thanks! I don't have a piggyback adapter for my ETX-125 so can't say for sure but the PST is not that heavy. If you need to you could add a counterweight system.
And:
Thanks for the info. Don
Subject: re: need dimensions of bolts used in ETX90 mount Sent: Friday, November 17, 2006 22:25:27 From: richard seymour (rseymour@wolfenet.com) I do not know the size for the OTA-to-fork attachment, but the base-to-tripod are 1/4-20 NC That is one-quarter inch diameter, 20 threads per inch "National Coarse" It is also the "standard" screw for camera tripod attachment to 35mm-sized cameras. have fun --dickMike here: The OTA to fork arms mounting screws are longer with a smaller diameter.
From: a. toonen (a.toonen@home.nl) Thank you for the answer. You are wrong however in expecting that Meade Europe will help me. A while ago I contacted Meade Europe to order a Meade 1.25" eyepiece holder for DS and DS-2000 telescopes #1002. My telescope has a 0.965 holder and this plastic part is offered at the Meade US website (spare parts) for 10 US$ including shipping. But they will NOT ship to Europe. Meade Europe advised me to contact the local (Netherlands) Meade importer. I e-mailed this company but never got an answer. Then I contacted a very friendly local Mede dealer who promised me to give it a try. After a week he told me that this part was not available. As last resort I contact the Meade US helpdesk by creating a "ticket" and descibing the above. I did that 3 times and got one reply that they were going to look at it. All I asked them was if they please could ship this lightweight item in a normal envelope to Europe. I would pay by credit card. I never heard from them again and I gave up. If I would have been a US citizen I could just order it. The DS2000 was my first, newly bought, telescope. So I do not rate the Meade customer service very high. That is why I am not even going to ask them for the missing bolts. Today I received your e-mail with the dimensions of the lower bolts. Thank you. I can purchase them here in any photographer shop. In the meantime I learned that once I have the dimensions of the other type of bolt, I can go to any car shop (where they repair cars) that services US cars. The have all these inch size bolts. The trouble is, that I do not have (yet) an ETX90 OTA, so I have no reference. Kind regards, Arnold W. ToonenMike here: Yes, we do not yet have a "global economy" where all countries and import/export laws are equal (or non-existent). Maybe by the 22nd century...
Subject: ETX125EC Polar Alignment Sent: Thursday, November 16, 2006 15:32:19 From: Ed Williams (hotstrings1@knology.net) Love you site and continue to learn from it. I have a problem. My etx125ec works fine in the normal Alt/Az mode when using goto. When I try to Polar align it wants to bind and also does slew in the right direction. I have checked to make sure that it is mounted in the 3884 tripod correctly and is. Also I made sure it was in Polar under the Telescope Mount section. I have an old etx90 M which is of course before goto and works great in polar. When I want to take pictures in the Alt/Az mode the object moves out of view hence the reason for wanting to Polar. I am also not clear as to whether you have to turn the OTA in the same manner as with the Alt/Az setting. Quite frustrating. I also have an lxd75 10" SN Meade which is Equatorial and works great and I want the etx to do the same when taking it camping etc. Thanks in advance for you help. EdMike here: Is the problem only occurring when you attach the camera? If so, I suspect you will need to add a counterweight system (lots of tips on the Helpful Information: Astrophotography page). Is the problem is occurring without anything extra added, it could be that the locks are either not engaging sufficient or are too tight. Also, have you done a CALIBRATE MOTOR and TRAIN DRIVES recently?
And:
it happens when nothing is attached. But as I said it works fine in the Al/az mode slewing to the object just fine. So that lead me to believe that the motor did not need trained. For instance when I do Polar and hit goto for let's say Altair which facing would be up and behind me on my right side alas it goes down. Go figure. Also again do I have to rotate the OTA before star aligment as you do in Al/as home position? EdMike here: Yes, you do have to the same CCW/CW rotation when setting up in Polar Mode before the alignment process. Since the slippage occurs when the base it tilted for Polar Mode I would suspect that it is the clutch mechanism that is the problem.
And:
Mike, is there a quick fix for this or do I have to send it to Meade? EdMike here: Whether there is a quick fix will depend on the exact nature of the problem, your expertise in fixing the type of problem, whether parts are required, and whether you are willing to run the risk of making things worse.
Subject: ETX90 EC Faulty Control Panel Sent: Wednesday, November 15, 2006 20:16:49 From: Ian (ibw@paradise.net.nz) The control panel, where the handbox etc plugs into is faulty in that a PCB board which is normally attached to the control panel has come adrift. I need to physically remove the control panel its self, it does move, but seems to be press fitted. I just cannot replace the PCB while the panel is in position. Is there any way to remove the panel that you know of? Thanks Ian WatsonMike here: I haven't tried to remove mine. You might search the site for "control panel" and see if there are any comments about removing it.
Subject: Fixing ETX105 to tripod Sent: Wednesday, November 15, 2006 07:33:27 From: henrik.van.holthoon (henrik.van.holthoon@wanadoo.fr) Yesterday evening yes indeed, stargazing, I screwed the ETX105 on to the tripod and to my surprise when it is not possible to turn the screws any further in you can still can move the ETX105 up and down vertically 1 to 2 mm this of no consequence in azm/alt position it will certainly not fall of the tripod but in the polar position this can not be correct. The screws can not be screwed completely in, they are blocked by a ring very strange. Most regards HenrikMike here: I presume you are talking about the #884 tripod. If both screws can not be fully screwed in then it could be the bottom plate is not fully inserted, so check that first. If the plate is inside the base as far as it will go, remove the base and check for any obstruction. DO NOT try to force the screws in as they could be hitting a vital component. If you can't find anything wrong, the simplest solution would be to add some extra "height" to the base so that it sticks up a little higher from the tripod mounting plate. Alternatively, you could shorten or replace the bolts.
And:
Yes it is the standard delivered tripod #884 with the ETX105. The problem is not the base plate or the telescope but the washers (rings) on the screws they stop the screws going in any further in the base of the telescope. The solution is either washers on top of the base plate tripod as you mention or below the base plate between the base plate and the knobs of the screws. As I told you it not a big problem springs and weight of the telescope keep the telescope from moving. In the polar position it is a different story of course. I understand from your reaction this is not as it should be as I though, negative point for quality control by Meade. Thanks Mike and regards, HenrikMike here: If the washers are riding too high on the bolts, you should be able to lower them down the bolt threads.
And:
Mike thanks, but I do not think this is possible what you suggest the washers are fixed in a groove at the lower end of the threat towards the knob. These washers stop the screws falling out of the tripod base plate and pretension the springs. The grooves must in the wrong place. Well one way or the other I will find a solution as long as the telescope is not used in the polar setup is does not matter. This I will possible never do. What I will do probably is to take the screw assemblies apart and put then a washer between the knob and the base plate that would solve the problem without going the threat too deep into the telescope base which could cause damage to the telescope as you rightly suggested. I think you have ETX as well, apparently you do not have this problem. Most regards HenrikMike here: My #884 tripod does not have this problem although I have had of some that had the washers coming off and the bolts falling out. Hence my comment about the washers possibly being too far up on the bolt.
And more:
From: henrik.van.holthoon [henrik.van.holthoon@wanadoo.fr] To: niall@njs101.com Hallo Niall, You must have great courage to take an ETX apart although I am electronic engineer and quite good (sorry to say this myself) but I would think twice to take an ETX apart but that may change of course. As you are ETX user yourself may I ask the following; I screwed the ETX105 on to the tripod and to my surprise when it is not possible to turn the screws any further in you can still can move the ETX105 up and down vertically 1 to 2 mm this of no consequence in alt/az position it will certainly not fall of the tripod but in the polar position this can not be correct. The screws can not be screwed completely in, they are stopped by a washer in a groove at the lower end of the threat. The washers (a removable ones) stop the screws from falling out of the tripod base plate. Do you have the same problem? I was using the ETX already for weeks but never checked if the dam thing was really fixed until two days ago. I will find a solution when needed but I was just wondering if I am the only one with this problem must be a fault in screw assembly i.e. groove to high. And do not be afraid if I find solutions which might help us all, I will them send to de great Mike site. I did see 2 days ago a beautiful Nebula in the Orion constellation very good clear image in the ETX 105 PE. Most regards HenrikFrom: Niall J. Saunders (niall@njs101.com) Henrik, I am surprised that you are having problems with the screw fitments onto the tripod top-plate. I certainly have never encountered this, even though I do not regularly use my ETX-105 any more (now that I have the LX90 on a wedge/pier in my observatory). However, even the other night, when I took the ETX out to help the local 'Brownies' (junior Girl Guides ?) attain their Astronomy Badges, I had no problems - I just 'popped' the OTA assembly onto the tripod and fully tightened the screws. I am sure that if you take the time to examine the setup in detail that you will be able to resolve the problem. Perhaps, by removing the circlip (watch that you do not lose the retained spring), you can remove the screw from the tripod top-plate and determine if the base of the ETX does actually allow the screws to fully penetrate, without restriction. Also, the base of the ETX should have three, quite thin (<1mm) rubber feet (which also conceal the screws that permit the base cover to be removed) - these feet, if missing, might be one of the causes of your problem. Let Mike and I know how you get on. Cheers, Niall Saunders Clinterty Observatories Aberdeen, SCOTLAND
Subject: ETX 105AT or ETX 90PE Sent: Tuesday, November 14, 2006 14:45:00 From: Gary and MaryAnn Pruden (garymap@comcast.net) Hi. I'm purchasing my husband a telescope for Christmas and am trying to decide between the ETX 90 PE with electronic eyepiece or the ETX 105 AT which costs $200 more but the 105AT also includes a DSI pro and dew guard free. He's basically a beginner but has wanted a real telescope for a long time and would like to take photos of what we see as well. Any advice would be most helpful. Thanks! MaryAnn PrudenMike here: Generally it is best to get the largest aperture telescope you can afford and that will actually get used. So you need to decide which is more important: the better portability of the ETX-90 or the larger aperture of the ETX-105. The PE model may not add that much to you over the AT model. As to the digital eyepiece, I don't find that they would be much use to me personally whereas the DSI would be more frequently used. For more on the various models see my comments on the Helpful Information: Buyer/New User Tips page as well as those from others on the Helpful Information: User Observations page.
Subject: ETX converson? Sent: Tuesday, November 14, 2006 13:39:09 From: Keith Raihala n0vj (raihala@yahoo.com) I have a Meade ETX There is an "off/on" switch on the bottom can it be converted to install a computer in it? Regards KeithMike here: See the item "Q. How do I upgrade to an Autostar capable model?" on the FAQ page.
And:
Subject: ETX Parts availability Sent: Tuesday, November 14, 2006 13:41:42 From: Keith Raihala n0vj (raihala@yahoo.com) I have a Meadw ETX is there a red dot sighting device that will work on my ETX? Regards KeithMike here: See the Accessory Reviews: Finderscopes page.
Subject: need dimensions of bolts used in ETX90 mount Sent: Tuesday, November 14, 2006 08:36:49 From: a. toonen (a.toonen@home.nl) Your website has been a great resource of technical information about DS2000 and ETX90 telescopes. I recently got a defective ETX90 mount with an electronic failure. With the help of your website and even the US patent office (Meade's patents reveal a lot of technical info) I succeeded in repairing this ETX mount. It came with no bolts, so the 4 bolts to attach the OTA to the mount are missing and the 2 attachment knobs to attach the mount to the tripod are missing. In the instruction manual I find no clue about the dimensions of these 6 "bolts". As these bolts have inch dimensions and we use metrics over here in the Netherlands I cannot just try which ones do fit. But I am sure, that you can tell me the dimensions of the two types of bolts that I need. When I have the dimensions, length and diameter (of the thread) it is much easier for me to acquire them. Thank you in advance for your answer and keep up the good work. If you think it is useful to others, I am prepared to write a small report about the repair of the ETX90 mount that had a real unexpected and hard to find but once found easy to repair failure and post it to you. With kind regards, Arnold W. ToonenMike here: Simplest solution is to contact Meade; they will likely send you replacement bolts for the ETX-90. And yes, would love to have the repair report.
Subject: 5th Annual Star Party Sent: Tuesday, November 14, 2006 08:42:14 From: Don (donmcclelland@adelphia.net) I was wondering about the Star Party you have planned if the free Meade telescope and cleaning applies to all apertures or just the ETX scopes? I would like to show up this weekend and bring my ETX125 but my 10" LX200 could definitely use the work. Especially the cleaning. Don McClellandMike here: Quoting from the announcement on the OPT web site: "Meade Technicians will be on hand to perform a FREE check-up and cleaning on your Meade telescope! This is a very popular event, and we recommend you arrive early in the day and be prepared to wait, as telescopes will be serviced on a first-come, first-served basis." There is no mention of an aperture restriction.
And:
Thank you Mike!
Subject: re: Observations and ideas about ETX105PE Sent: Monday, November 13, 2006 22:01:08 From: richard seymour (rseymour@wolfenet.com) That was a very comprehensive review. You wrote: ----------------- Change power source: If you change over from internal to external power and visa versa (input in power plug or internal batteries) it is claiming we should do motor calibration. I fail to understand why this is necessary, the drive systems are closed loop systems with encoders in the loop for feedback, changing the input voltage within limits should not have any affect. It has not any effect on my ETX105 anyway. I might be wrong but I do not think so. -------------------- The Calibration procedure adjusts the brightness of the LEDs shining on the encoder disks. Meade uses cheap molded plastic which is semi-transparent. That causes the encoders to still see some of the LED light after the "edge" of the encoder vane moves between the sensor and the light. Calibration spins the motors quickly, and adjusts the brightness to cause a "square wave" of 50% "on" and 50% "off" to be seen by the sensors. If Calibration is -not- done, and if you are unlucky, the encoders might not see one (or some) of the vanes truly turn the light "off" as they passed by. If the Autostar detected that "lost" on/off/on transition, it would declare a Motor Unit Fault. So the Calibration is adjusting the one "analog" portion of the servo system. As you correctly wrote, the remainder is all digital. Some models (LX90, LXD family) use metal encoder disks (not plastic), so calibration is not as much of a problem. have fun --dick
From: henrik.van.holthoon (henrik.van.holthoon@wanadoo.fr) Hello Dick thanks for you extensive explication. I am used to electronic precision theodolites with build in distancers with very precise reading circles for vertical and horizontal readings and we are talking about sub arc second precision and +/-1 mm for the distance. I worked 25 years for Leica Geosystems. These instruments are between 20000 and 30000 dollars completely different technology compared to our ETX telescopes. In these instruments any backlash is unacceptable. The more expensive instruments like you mention will undoubted have a more robust construction. You may be correct that a tension fall will influence the leds of the encoders but my ETX105 does not get nervous by changing from internal to external power. I would anyway advise people to use an external rechargeable power pack better not use power line power supplies because of possible transients on power lines although they get somewhat damped by the transformer. Thanks again and have fun yourself. Henrik
And:
From: Niall J. Saunders (niall@njs101.com) I just wanted to help you understand why the 'Calibrate Motors' step is so important if your power supply voltage changes. On each axis of the ETX (and LXD / LX90) scopes, Meade uses a single slotted disc to indicate how far the MOTOR that drives the gear-train is rotating (and indeed, how fast). It is especially important to note that this measurement takes place RIGHT AT THE MOTOR OUTPUT SHAFT, before ANY gearing takes place. It is also very important that this is the ONLY feedback that the Autostar gets from either axis - there is NO FURTHER FEEDBACK anywhere else along the gear- train. So, if you have not carried out a suitable, effective, and applicable 'Calibrate Motors' routine, then EVERYTHING that the Autostar will try to do will be hopelessly compromised. Your GoTo's will be out, tracking will be out - even initial alignment can fail. So, if you suspect that your supply voltage fluctuates (very often the case with internal batteries), then you need to 'Calibrate Motors' regularly - at least at the start of every viewing session. If you are running from an AC power adaptor (and if this is PROPERLY regulated) then you may suffer less. This is also the case with the larger DC 'power-tank' units, certainly those that rely on an internal 17Ah sealed-lead-acid battery - although these will hardly be affected by normal usage of the scope, it is wise to keep them regularly charged, so that the Autostar sees a relatively constant voltage. It does not take that much of a voltage fluctuation to start introducing strange behaviour - so, be prepared !! Why does it happen? Well, the Autostar illuminates one side of the slotted disc (or, for the cheaper scopes like the ETX range, the disc is not slotted, but is actually just a plain disc with black lines painted on it) and detects light passing through (or reflecting off) the slots (or the gaps between the black lines). The source of the illumination is a simple IR LED. There are no 'guide slots' next to the rotating disc (unlike the system used in the more expensive LX200-type scopes) - when present, these help eliminate any 'stray' light from illuminating those slots (or lines) around the one that is actually passing over the detector (the only slot/line that ACTUALLY needs to be detected as it passes). In other words, if the LED illumination was too bright, then extra slots/lines might possibly be detected (resulting in the Autostar thinking that the motor was rotating faster (or further) than was desired. Conversely, if the illumination is too low, then slots/lines may not be counted as they pass the detector. In order to overcome this (without huge financial outlay) Meade use a clever process whereby they spin each motor axis (in turn, hence the two bursts of movement) whilst they adjust the LED output power from minimum to maximum. The Autostar knows that the motors have been commanded to run at maximum speed and, barring anything jamming the axis, they expect to see the output of the detector vary from nearly always off (minimum LED power), through to nearly always on (at maximum power). At some crucial stage in the process, the Autostar will detect a waveform whose 'mark/space' ratio is effectively '1:1' - i.e. a 'square wave'. This is the 'ideal' output power for the LED - and the configuration of the PIC chip that is feeding current to the LED is stored for future operation by the Autostar. (For the 'techies' reading this, and if memory serves me correct, there are 127 different possible power levels, obtained from a seven-bit output coming off the PIC chip. Each output drives a resistor of a different value - in a 2^n scale - such that there is a 'summed output current' available, depending on which of the seven bits are at 5V. The 'summed current' passes through the LED, providing the variable illumination.) Fortunately the tolerance is quite low, and so a certain amount of voltage fluctuation can be accommodated. But, presumably to keep costs in check yet again, there is NO VOLTAGE REGULATION on the motor driver boards themselves. That is why, if you choose to run your scope off, say, a 15V supply (possible, but maybe not recommendable) then your top-end slew speeds will be MUCH faster. Obviously, the lower-end Guide speeds are controlled, and are therefore not affected by the higher voltages. Certainly, whenever Mike replies to queries with his infamous "Reset, Calibrate Motors, Train Drives" response, I would always like to emphasise that I consider that the order that these instructions are given reflects the importance of each when it comes to solving problems. Anyway, I hope this helps. Best Regards, Niall Saunders Clinterty Observatories Aberdeen, SCOTLAND
And:
From: henrik.van.holthoon (henrik.van.holthoon@wanadoo.fr) Hello Mike I invoked quite a discussion on your site, big fun and interesting. This is my response to Niall. Regards Henrik ----- Original Message ----- From: "henrik.van.holthoon" <henrik.van.holthoon@wanadoo.fr> Hello Niall, Thank a lot for you more then extensive response, be assured it is appreciated. I do understand now the possible influence of input voltage it beats me why it not mentioned in the Meade handbook. Anyway I will now regulary do a motor calibration it is quickly done in fact but I will stick to a power pack instead of a line power supply.Where I live in the country we have 245 VAC instead of 230VAC and what is worse the power line is not very clean, transients you know (voltage spikes). With a DC power pack you do not have this problem and it is easy to take with you. I am wondering how do you know so much of the electronic construction of the Meade goto telescopes. Ha ha I will be quickly an expert myself if we go on like this. Most regards Henrik
And:
Henrik, I am happy to be of assistance - after all, I know how much help I received from Mike Weasner's site when I first purchased my ETX-105 !! As far as details being mentioned in the Meade Handbook, it is perhaps easier to consider Mike's web-site as the 'Official' Meade Handbook !!! Yes, I would STRONGLY recommend using a 12V DC power-pack - it is far more reliable, and you gain an added advantage that you may even be able to start your car when ITS battery fails ! (There is also the inherent danger of using mains powered equipment in an external environment - made even more dangerous by working in the dark. As far as understanding the electronics inside the Meade Scopes - well, my one was faulty when I bought it (ex eBay) and I decided I would just take it to pieces, figure out how it worked, fix the broken bits (the hard-end-stop on the RA / Alt axis), and then put it back together. I was also extremely curious about how the axis control worked - after all, that was what I did both as a hobby and as a profession. What that meant was that I had all the appropriate equipment to 'look at' the signals, and the experience to understand (roughly) how the internal code algorithms must be working. I have to also defer my knowledge the huge wealth of information made available to us by Dick Seymour - he truly has 'burrowed' into the depths of the AutoStar - in fact, he may even have a better feel for how the program works than the programmers at Meade themselves. Certainly I am convinced that the programmers at Meade are NOT actual astronomers themselves - they simply provide 'code to request'. This is perhaps why the AutoStar has so many shortfalls. And, finally, yes - it will not be long before you will (hopefully) be confident enough to share your accumulating knowledge with others. That is the wonder of sites such as this. Good Luck, And Clear Skies Niall Saunders Clinterty Observatories Aberdeen, SCOTLAND
And more:
Thinking about the construction of the motor drives with the encoder on the motor axes is not what I call a robust feedback system the encoder should be paced on the vertical and horizontal axes then at least you are measuring the real movement of the OTA. In our ETX the backlash is as I understand not compensated as the OTA is always moving left and right, avoiding it rams the stop in the horizontal plane this system is introducing errors in the positioning. If you do a star hopping or a guided tour you must have a positioning error becoming greater after looking for a number of items. This what I have seen already I think, to overcome this one should a reorientation I think after let say after 10 to 20 objects. But I know it is all a question of cost of course it would be certainly more expensive to install a more robust feedback system on our ETX. Apart from that, it is a fantastic telescope. Regards Henrik
Yes, the feedback system is a compromise between accuracy and cost - as always. However, if you take special care to Calibrate Motors, and to Train Drives, you might be surprised just how accurate the system actually is. If you want to improve accuracy even more, the system you have suggested is actually available to you as an option within the Autostar software. If you select <Setup>, <Telescope> and <High Precision> then the Autostar will take you to a Guide Star each time you jump to a new object (unless, of course, you are heading to a Guide Star anyway. This is the mode I operate with all the time, on my LX90. It is very easy to use, and very reliable. If you make sure that your Finderscope is 'accurately' aligned with the OTA, then it should be very easy to centre the Guide Star, and to then be confident that this will also be central in the OTA filed of view as well (even at high magnifications, or when imaging). Centre that star and you will find that whichever 'faint fuzzie' you are chasing will be in the FOV - even if you CAN'T see it !! Going back to my Train Drives comment - have a search through Mike's site, and see what I have posted in the past - especially looking for my 'modified' Train Drives routine. I would certainly never consider operating any of my Meade scopes without taking the time to train the drives properly. By doing this as accurately as possible, virtually ALL of my gear-train backlash is eliminated. Once this stage is completed, you can also then adjust the RA/Alt and Dec/Az 'percentages' until, even at x1 'Guide Speed' you can confidently move the image around to exactly where you want it to be - with no 'overshoot', 'rubberbanding' or 'post-button-release drift'. Finally - just take a few moments to consider the level of resolution that would be necessary if you were to use a position sensor AFTER the gear train. Even for a resolution of 60 arcseconds you would need to be able to resolve 21,600 'positions' (1 minute x 60 minutes/degree x 360 degrees/revolution). I have used sensors in feedback control systems in the past - and the best I could afford for the project was a 2,000 lines/revolution sensor that, with clever software algorithms, we were able to extend to 8,000 lines/rev. And that was at a cost of over $700 per encoder - and would still have only allowed 3 arcminutes of resolution! What Meade has achieved is FAR better than that !! Cheers, Niall Saunders
And still more:
An other response on the follow up by Niall. Concerning ETX fixing on tripod I will report my solution in solving this to you later. Hi Niall, This is a great help, I will certainly try this [high precision command] and observe what happens. Coming back on resolution I worked for Leica Geosystems they make GPS positioning equipment and electronic precision theodolites with sub second accuracy they have a very robust feedback system but they have incorporated high precision coded disks which are read electronically all digital of course but we are talking about 20.000 to 30.000 dollars this is of course a different piece of cake. You remark about the achieved position accuracy of Meade telescope made me realise I should have more respect for what they have achieved at relatively low cost. One last question I put the Ra/Alt and Dec/Az percentages at 15 % or should I experiment for better result in other words are these value different for every ETX105's. Cheers and have a nice weekend. Henrik
And:
It is not possible to state what the 'best' values are for the Percentage parameters - you will have to experiment. What you are trying to achieve (after having Calibrated Motors and Trained Drives) is a 'rapid' response whenever you change the slewing direction on a given axis. When the values are at 0%, the Autostar does not compensate for the 'slack' in the gear train whenever it has to change direction. It certainly 'knows' what the 'slack' is - this is what it 'learns' when you execute the Train Drives routine. It 'learns' how many extra pulses need to be detected from the encoder wheel when it has to 'unwind' all the gears from, say, having been rotating in a clockwise direction, before ANY movement would start to happen in an ANTI-clockwise direction. So, when you change from one direction to another (or if the Autostar has to do this for itself) the Autostar 'adds' the appropriate amount of 'extra' movement - just to compensate for the HUGE gearing reduction that is present, and which means that a sudden change in direction of the motor rotation will have NO immediate effect on the change of direction of the axis. I hope that this explanation makes at least 'some' sense. That said, it may become obvious that, if a large amount of adjustment is needed when the motor direction changes, if nothing is done about the speed at which the adjustment motion is applied, then there will be a significant delay between a change of direction being requested, and the resulting change being observed. The Percentage values allow for the compensating adjustment motion to be applied at a HIGHER speed than is currently the case (except when the speed is already at speed 9, which is the maximum possible anyway). Specifically, the percentage value describes a 'nominal time period' for which the speed will be enhanced - to allow the compensation to take place quite rapidly. If your Percentage values are too low, then the latter part of the adjustment will still take place at the current operating speed - and a delay might be noticed. If your Percentage values are too high, then the motion at direction change will be 'jerky', and may even lead to overcompensation. Trial and error is needed - but you MUST have adequate Motor Calibration, and it is ESSENTIAL that you have done the Train Drives with the utmost of care. I strongly recommend a 'cross-hair reticule eyepiece', but a little bit of ingenuity, and some very fine thread - or human hair !! - will allow you to easily modify the 'standard' Meade 26mm SP eyepiece to achieve this. Good Luck, Niall Saunders Clinterty Observatories Aberdeen, SCOTLANDMike here: Besides Niall's comments above I also recommend Dr. Clay Sherrod's article "Setting Percentages For Better Tracking" and Dick Seymour's article "Calibration, Training, Percentages" on the Helpful Information: AutoStar Info page.
And:
Thanks again Niall and Mike Your suggestion about a cross hair ocular or modify 26 ocular is a good one I will try the last one first. It not easy without a gross hair to put a target exactly in the middle of the ocular. For the rest high precision command, use Polaris as a target are valuable recommendations I did not think about that one. Thanks again Regards Henrik
Subject: Plastic Horizontal Lock Lever ETX-125 Sent: Sunday, November 12, 2006 09:52:43 From: Jeff Rushing (jarushing@cox.net) Is there a replacement for the cheap plastic horizontal lock lever available that you know of? I have now broken my second one. The first was replace by MEADE when I sent the scope in for other repairs. Now, I just need this plastic piece. I do not see them on the MEADE website. Are there any metal options out there? I have resorted using a combination wrench, but am scared I am going to over tighten it. Thank You, Jeff RushingMike here: See the Helpful Information: Telescope Tech Tips page for some alternative levers you can make.
Subject: Re: etx 125 electric focusser takes off on its own Sent: Saturday, November 11, 2006 14:23:01 From: Chris and Claire Nuttall (c.nuttall@tiscali.co.uk) Thank you for your prompt and helpful reply, i hope you got a good view of mercury, i was lucky enough to observe the entire of the last transit from my home in london....it seems odd that someone could be sheltering from the heat when it is so gloomy and cold here! I tried the 12 volt power supply, it didn't cure the problem I also tried reseting the autostar as you suggested, this didn't solve it I tried cleaning the keys and that didn't work either ( the focusser will continue to run after a few presses of any of the four direction keys so actually i doubt it is that anyway, also it never sticks while slewing the scope) I have no other funny autostar oddities to report. Do you think i may need to reload the software into the autostar? I dont have the cable for doing that but if you think it may help then i could get one and try it. I have been re-reading your book and scanning the website for ideas, but to tell you the truth i'm stumped. chrisMike here: If you have the focuser handcontroller you might try that by itself and see if you get the run-on problem. As to the #505 serial cable, it is simple to make; there are several articles on it on the Helpful Information: AutoStar Info page. NOTE: if your computer does not have a real RS-232 port and only has USB, then you will need a USB-serial adapter. But not all adapters work with the AutoStar; see the article "AutoStar and USB" on the AutoStar Info page.
Subject: Avoiding the Desire to Collimate Your Maksutov Sent: Friday, November 10, 2006 15:12:02 From: Bubba Martin (bubba@morego.com) I read the article titled "Avoiding the Desire to Collimate Your Maksutov" and I disagree. Although both Meade and Orion supply fairly good scopes, I've had at least one that was slightly uncollimated as delivered by the factory. Tweaking one of the six screw an eighth or sixteenth of a turn won't affect alignment of the primary/secondary as much as one would think. It DOES place the scope in perfect collimation which is a MUST for planetary / high power observing. Readers of this article should not be discouraged from placing their scopes in perfect collimation and robbing them of the views they deserve from pretty good optics. I've collimated newts (24"), true casses (up to 24"), maks (5") and yes, even one refractor (only 4") and can't imagine putting up with poor viewing due to an adjustment most people could make if they only knew how. Good seeing, Kerry Martin Kara Technology Corp.Mike here: I totally agree that ensuring telescopes that are meant to be user-collimated ARE collimated is a really good idea. However, the ETX models are NOT meant to user-collimated and there are no easy access screws to adjust the collimation. That was the point of Dr. Clay's article. That said, there are articles on collimating the ETX Maksutov-Cassegrain telescopes on the Helpful Information: Telescope Tech Tips page. It is just not something to be undertaken lightly as without the proper patience the ETX owner can make things worse. And due to the design of the ETX models, they do not typically get out of collimation under normal use.
And:
thanks for your timely response. I agree with that. A novice can render a perfectly good scope unuseable in no time at all. But what do you do when you star test your ETX and discover that Meade sent one that won't pass? Do you have to send the whole scope back if you're a novice? Bummer. I confess I have zero experience with the ETX. My Orion 127 Mak is a real pain to collimate (six screws), but at least I can do it given good seeing and a couple of hours with a LOT of patience. Do you have any experience with the Orion Mak? It doesn't appear there is any way to collimate the secondary, and I've already sent one back due to misalignment of the secondary spot/baffle. A special tool is required just to remove the secondary retaining ring, and I'll bet my machinist friend would charge me at least $100 to make one... Thanks, Kerry MartinMike here: If an ETX arrives out of collimation it should be returned to the dealer immediately. If out of warranty and the owner wants to try it, those collimation articles I mentioned will help. I have no experience with the Orion telescopes.
Subject: Is it safe to work on my ETX-125? Sent: Thursday, November 9, 2006 13:53:10 From: Robert Harris (RHarris@kiersted.com) I just purchased a new ETX-125 AT, and I'm curious if the improvements described in the "Performance Enhancement Creating The Perfect "GO TO" ETX or LX 90" section of your site are still applicable to it. This recent post from Dr. Clay suggests they are not: ----- Original Message ----- Subject: Re: clutch adjustment Sent: Wednesday, November 8, 2006 03:05:28 From: P. Clay Sherrod (drclay@tcworks.net) I do not recommend that the customer work on the NEW version of the ETX (any with metal fork arms) at all. The overall construction and method of repair has totally changed and pretty much is out of the reach of the average consumer. Dr. Clay Are those modifications safe for a new ETX? Thanks! Robert HarrisMike here: Some of Dr. Clay's enhancements could be OK and some probably not. Since he is the author of those articles and an expert in hardware, I would seriously consider taking his advice.
Subject: Transit of Mercury Sent: Thursday, November 9, 2006 04:43:16 From: ROBERT Derouin (bobcath28@msn.com) Hi Mike!! Yes, It's been a while! I just wanted to congratulate you on your AWESOME images of the Transit of Mercury of Nov. 8, 2006!!Beautiful Job!!! It was a total rainy washout here in Cranston, Rhode Island...(where I work!). Sorry to say, I have NO images to send you!! I'll just keep on enjoying yours and look forward to seeing the images of your other website fans who have gotten great shots!!! Keep up the AWESOME work Mike, we here in RI appreciate it!!!! Bob Derouin Johnston, RI
Subject: etx 125 electric focusser takes off on its own Sent: Wednesday, November 8, 2006 14:38:37 From: Chris and Claire Nuttall (c.nuttall@tiscali.co.uk) I have an etX125 and autostar that i have owned from new for about five years, this problem used to happen very infrequently, it has started happening all the time now. i will be carefully focussing an image on low speed just dabbing the button a little at a time to get perfect focus, and then it is as if the button is stuck and the focusser just keeps going. i have franticly prodded at the button while this is hapening but it doesn't stop. the only way to stop it is to switch off the scope, then when powered on again it is fine, until the next time! I use a small battery pack, to power the scope, i am going to try powering it off a mains adapter, then my next idea was to take the autostar apart and clean the contacts.....but before i waste several evenings do you know what the cause may be? many thanks Chris nuttallMike here: If there are no AutoStar related oddities (random slews, poor GOTOs, etc.) then I would suspect a sticking key. See the article "Keypad Cleaning" on the Helpful Information: AutoStar Info page. But before you dive into that you might just want to try a RESET of the AutoStar; you will have to re-enter your site info and any objects you had added but if that solves the problem you won't have to "go inside".
Subject: Re: clutch adjustment Sent: Wednesday, November 8, 2006 03:05:28 From: P. Clay Sherrod (drclay@tcworks.net) I do not recommend that the customer work on the NEW version of the ETX (any with metal fork arms) at all. The overall construction and method of repair has totally changed and pretty much is out of the reach of the average consumer. Dr. Clay ------------- Arkansas Sky Observatories Harvard MPC/ H43 (Conway) Harvard MPC/ H41 (Petit Jean Mountain) Harvard MPC/ H45 (Petit Jean Mtn. South) http://www.arksky.org/ ----- Original Message ----- From: "fred gagnon" I was wondering if it is still possible on the newer models of the etx125 to adjust the RA cluch by very slightly and cautionly loosen the cluth bolt if the assembly is to tight, I did read the post about what happened to the other guy who tried to remove it but I was not sure if it is still slightly adjustable
Subject: Meade ETX, What on earth is? Sent: Tuesday, November 7, 2006 20:06:37 From: Eric West (eric@hayleymedia.com) Just about to launch into the purchase of an ETX 90. Both the PE and the AT are available. The salesman, (surprisingly since it is $100 cheaper), recommends the AT over the PE because of the red dot view finder on the PE, which is apparently too fragile. He also says that the other things which come with the PE (a level and a "Northfinder") don't make up for the viewfinder deficiencies. Do you have a view on this? Also, I have gathered from the forum that an OTA is the telescope tube, but what does this actually stand for, nothing I can think of fits! In a similar vein, what on earth is a GEM? This is a great site, I can see myself spending hours here! Regards Eric West Auckland New ZealandMike here: You can see my report on the Premier Edition model on the Helpful Information: Buyer/New User Tips page. Other user reports are on the Helpful Information: User Observations page. Basically, the LNT/Smartfinder are worthwhile if you don't know (or don't want to learn) the night sky and just want to see objects or if you change observing locations a lot. Some people find the red-dot finder easier to use than a magnifying finderscope and vice versa. OTA = Optical Tube Assembly. GEM = German Equatorial Mount.
Subject: MEADE ETX 125 Sent: Tuesday, November 7, 2006 03:18:17 From: AL ZUBAIR MOHAMMED AL ZUBAIR (zmzubair@omantel.net.om) Great site and extremely helpful. My ETX125 fell and some parts came apart. I need a wiring diagram to indicate what wire goes where in the board that controls the vertical drive. The wires detached and there is no indication where each color (wire) goes. appreciate any help. Thanks zubairMike here: No "wiring diagram" is available but there are many articles on the Helpful Information: Telescope Tech Tips page with inside photos that will probably help. Look through those.
Subject: Meade 884 Tripod Sent: Tuesday, November 7, 2006 00:15:44 From: glen ilacqua (g_ilacqua@yahoo.com) I just thought you and your readers would like to know that the Meade Factory outlet has Refurbished 884 tripods with carry case for $59 shipped (CONUS). I just ordered one for myself . It's a good opportunity for people to do polar alignment tracking... and it's a great upgrade from the flimsy aluminum models supplied with the ETX 60-70-80. Glen Ilacqua
Subject: Focus Knob on ETX-70 Sent: Sunday, November 5, 2006 12:11:45 From: Anthony Favata (tonyerin@epix.net) Have had an ETX-70 for nearly two years now, and focus knob has always presented a problem--primarily slippage that I can reduce somewhat using the allen wrench that came with the scope. However, in the last couple days, no matter how hard I try to tighten this focus knob, the slippage is very difficult to manage, and in many cases the knob is completely coming off. I am gearing up for Wednesday's transit of Mercury and I am looking for some advice on some kind of quick fix. Thanks, Tony FavataMike here: You could replace the knob with something else; see the Helpful Information: Telescope Tech Tips page for lots of ideas.
Subject: re: 887 Field Tripod Sent: Sunday, November 5, 2006 11:51:34 From: richard seymour (rseymour@wolfenet.com) > Does the tripod, wedge and scope need to be > exactly level for Polar position? No. It's -convenient- if they're close to level, since it makes (for example) the latitude adjustment scale vaguely accurate. But it is -not- necessary. All that's really necessary in a wedge situation is that the wedge plate be perpendicular to the line beween you and the celestial pole. Then the RA axis is parallel to that line, and the rest of the mechanism revolves around that axis. The RA axis doesn't care which way the tripod legs are pointed as long as the axis itself is aligned to the sky. (consider that even a "perfectly level" mount will have its legs "rotated" 90 degrees westward (as the earth spins eastward) across the span of the next 6 hours...) When i'm faced with operating on a slanted surface, i bring along short sections of planks (6" x 6") to place underneath the tripod feet (also useful for spreading the load on soggy ground to prevent tripod feet from sinking slowly into the muck during the evening). Conversely, you could also press the "long" legs -into- the dirt to "shorten" them (or bring a little shovel...). have fun --dick
Subject: Buying a First Telescope Sent: Saturday, November 4, 2006 12:10:32 From: Alexndr333@aol.com (Alexndr333@aol.com) I'm looking to purchase my first telescope and would appreciate one or two basic pointers from you. I'm 53, intelligent, but not highly mechanically inclined. My home is in Palm Springs, where I'd be interested in stargazing, perhaps some computer photo printing, but mostly want to stare into the sky. There are no kids - this is for me. I'm willing to spend up to $1000. I'm mostly interested in your recommendations for the type of telescope and any significant features I should consider. Thanks in advance for any thoughts you can offer. - Craig A. Ewing - Palm Springs, CaliforniaMike here: Well, I need more info before making any real recommendation. If you just want to "stare" into the sky, perhaps a Dobsonian would be best. On the other hand, if you want the ease of a GOTO system, perhaps an ETX-125PE would be the right thing. Or perhaps one of the LXD75 models. Lots of choices but first you need to decide on what you really want to do with it. Is aperture more important than the mount? Is visual work more important than astrophotography. You might want to read through the Helpful Information: Buyer/New User Tips page articles as well as the Helpful Information: User Observations page. For more on the LXD models, see my LXD55/75 Site (http://www.weasner.com/lxd).
And:
Thanks for your thoughts. I'll continue to peruse your website for the observations you and your correspondents have offered. All the best, - Craig
Subject: ETX125 How to open the OTA to fix the focus knob shaft? Sent: Wednesday, November 1, 2006 12:45:30 From: Alexandre Koukarine (sand@coresrv.berkeley.edu) Thank you very much for your site! I have a problem - the focus knob shaft fall inside the OTA and I can't get it back. I've searched the entire site but didn't found any guide for that. (though, I've found this question asked once in archives, - the answer was not given). Please help! The Mercury transit event is coming! -- Best regards, ---------------------------------- Alexandre Koukarine CORE IT Support and Development School of Optometry, University of California 387F Minor Hall, Berkeley, CA 94720-2020Mike here: Did the article "Focus Shaft Fix" on the Helpful Information: Telescope Tech Tips page not help?
And:
Thank you very much for the prompt reply! Your site is so huge! No wonder I've missed that article even with google search. I'll try that sequence today. Actually I've tried to unscrew the base by bare hands but it was not moving, and I was afraid of breaking something. I plan a fantastic focuser knob mod and an electrical wiring mod, and would like to share the ideas and the procedures with your site visitors. Should I just send you the text and the images when I'll done? Best regards, AlexMike here: Looking forward to the article.
Subject: 887 Field Tripod Sent: Wednesday, November 1, 2006 08:58:16 From: Jack Fox (jackfox@mindspring.com) I have just purchased the Meade 887 Advanced Field Tripod and wedge. How do you level the tripod with the wedge and scope attached? The legs are a fixed height. Do you have to shim the legs somehow, that would be an unsteady set up. I have checked the Wedge section on your site and did not see a solution. Does the tripod, wedge and scope need to be exactly level for Polar position? Any help would be great. Jack FoxMike here: I don't have one so can't say for certain but from the description I don't see any leveling adjustments.
Check the Feedback Archives for previous editions of the Feedback page.
Go to the ETX Home Page.