Last updated: 3 June 1999

ETX-90EC Many readers and contributors to this ETX web site have suggested that Meade should send me an ETX-90EC and Autostar. Well, recently Meade did just that! I received an ETX-90EC ($595) with an Autostar Computer Controller ($149; software revision 1.0c). I'm continuing to use the ETX-90EC and Autostar, weather permitting, but here are my initial experiences. I will update this review as I work more with the ETX-90EC and Autostar. I do not intend to address all the features of the Autostar on this page; just some of the features that most users will find useful and how well these features work. I encourage everyone to read the ETX-90EC User Feedback pages and Meade ETX-90EC Press Releases for additional information and comments.

The ETX-90EC comes with a revised manual, an ETX accessory catalog (Meade's), and a registration card. The manual is much improved from the original ETX manual and includes more details on polar aligning and troubleshooting. The optics and optical tube assembly (OTA) remain the same high quality as with the original model ETX. The drive base and fork mount are totally new, but still have a lot of plastic. The ETX-90EC includes the 8x21mm viewfinder, 26mm Plossl eyepiece, and the new Electronic Controller (more on the Controller further down). The table top legs are no longer included.

After unpacking, you insert 8 AA batteries (not included) in the drive base. Access to the battery compartment is much improved from the original model (which used only 3 AA batteries); you just pop off a large plastic door. The extra power is required for the slewing (and optional focusing) motors and to power the Autostar. After I installed the viewfinder and the batteries, I then went to mount the ETX-90EC on the Meade Deluxe Field Tripod. As noted by others, the original mounting bolts included with the Meade Tripod are too long for the new model ETX. This can be corrected by requesting shorter bolts from Meade or by adding a washer to each bolt. I chose to add the washer. The next minor glitch was that the original ETX-90EC manual (figures 12 and 28) showed the ETX mounted incorrectly. I first noticed this when I saw that the table top leg mounting holes on the side of the base would have pointed skyward instead of earthward (see figure 15 in the manual). The photos below show the ETX-90EC correctly mounted on the Meade Deluxe Field Tripod.


Also shown in the photo on the right above is the Electronic Controller that comes standard with the ETX-90EC. Using the Electronic Controller you can slew the ETX-90EC in altitude (up/down) and azimuth (left/right) for terrestrial usage. There are also focus in/out buttons on the Controller for when you purchase the optional Meade electronic focuser. You can change from Alt/Az to polar mode (northern or southern hemisphere) which engages the Right Ascension tracking motor. You then use the Controller to slew in RA and Declination. Unfortunately, the setting is not retained once the ETX power is turned off. To set the mode you press the MODE and SPEED buttons in a certain sequence and so you'll have to remember and repeat this sequence for every power-on. You can, however, set a default startup mode by removing one or two screws from the Electronic Controller backplate.

There are some initial setup steps to go through, including testing the drive motors to be certain they work properly; I tested them and all was well. I then took the ETX-90EC outside and got in some observing before the clouds came in. While polar aligning the ETX on the tripod, I discovered that the DEC setting circle was off by 5 degrees. The manual describes how to correct this but it was a surprise that it was off by so much. (Tip: It helps to use a rubber bottle-top gripper to turn the cover plate if it is very tight.) Optically, the views are of the same excellence as with the original model. When the Electronic Controller is set for polar mode and the power is turned on, the ETX accurately tracks smoothly and quietly in RA. There are four slewing speeds for both RA and Declination, the highest speed being for large movements across the sky to manually locate objects. In fact, the manual implies that this is the preferred way to move the ETX tube versus unlocking the RA and DEC locks and manually moving the scope. I was surprised at this but the speed is fast enough to actually make this practical. The only drawback is that the drives are rather loud at this high speed. The next slower speed is for minor movements to accurately position objects in the viewfinder or low-power eyepiece. The two slowest speeds allow for precise positioning in higher power eyepieces or for correcting for a not-quite-accurate polar alignment. Using the Electronic Controller to slew the ETX will move the scope in a manner more appropriate to terrestrial observing than astronomical observing. Left and right button presses result in left and right, respectively, movements of objects in the viewfinder. But since the view through the eyepiece is reversed left-to-right, the buttons seem to work backwards. Once you get used to this it becomes only a minor nuisance for astronomical observing. While slewing in RA at the highest speed, the RA drive motor would stop slewing after about 1 hour of RA movement in either direction. Releasing and repressing the RA slewing button would slew the ETX for another hour of RA and then it would stop. This only occurs when in the Polar Alignment mode; in the Alt/Az mode there was no motion stop. This was not mentioned in the manual. The RA tracking would resume once the controller button was released. At the other three speeds there was no motor shutdown nor was there any shutdown in the DEC slewing motor at any speed. At the two slowest speeds, both the RA and DEC motors sounded "hesitant" in that there was no constant volume or frequency to the motor sound. Functionally, both motors slewed smoothly so I guess everything is as it should be.

Manual focusing is the same as with the original model ETX although it seems to be "tighter" in the new model. When mounted on the Meade Tripod, hand induced vibrations (in the 26mm eyepiece) are minimal but the optional electronic focuser would make a nice addition (just as did the JMI MotoFocus on the original model).

As many of us have experienced with the original model ETX (now called the ETX-90/RA), views through the ETX-90EC with the supplied 26mm Plossl eyepiece are sharp and thoroughly enjoyable. And just like with the addition of the Microstar Dual Axis Drive Corrector to the original ETX, having electronic control over both the RA and DEC axis in the new model makes using the ETX-90EC even more enjoyable.

If you elect to purchase just the basic ETX-90EC you will have a fine astronomical or terrestrial telescope. For astronomical viewing you will want a sturdy tripod or the optional table top legs for polar mounting the ETX. That is, unless you add the optional Autostar Computer Controller ($149), which can drive the ETX-90EC in Right Ascension even in the Alt/Az mounting mode.

OK, so what is it like using the Autostar? Read on.

ETX-90EC The next day I connected the Autostar Computer Controller. The Autostar replaces the standard Electronic Controller. As can be seen in the photo on the right, the Autostar is larger than the Electronic Controller, with more buttons and a display screen. With the Autostar there are nine slewing speed settings instead of four. There is even a small red LED "flashlight" on the end which can be turned on and off.

The initial setup is straight forward and actually simple, as long as you follow both the printed instructions and those displayed on the hand controller's screen. During my initial setup two minor "problems" surfaced. I still had the ETX mounted on the Meade Tripod with the Tripod set for polar alignment. But the initial Autostar setup requires that you use terrestrial objects to "train" the Autostar for your drives. I rotated the ETX OTA until it was horizontal and pointed at an object. Unfortunately, that put the OTA near the hard stop for the "altitude" movement. Plus in this horizontal position, the ETX would not slew back "uphill" to a vertical position. I corrected this latter problem by manually rotating the ETX about 90 degrees around the azimuth axis and then used the drive motor to move the OTA horizontal again. I verified that the ETX was not near any azimuth hard stops. This adjustment did eliminate the problem and I could proceed with the drive training (although I was concerned about the altitude training since I was near that stop).

This initial setup takes just a few minutes and, except for entering the date and time on each power-on, does not need to be repeated except in certain conditions like attaching the Autostar to a different ETX, correcting errors in the training, or changing your observing location.

The Autostar display is easy to read, even in bright sunlight (for the initial setups). The letters are white on a black background, which helps a lot. The manual (yes, it is printed on thin paper as others have noted) is not necessarily required at all times since there are clearly worded prompts on the display. Once you know the basics you can navigate through the Autostar menus. But it would have been nice for Meade to have included a small laminated card with some basic alignment (and other) instructions. Hum, a third party opportunity? The Autostar controller itself is lightweight and easy to hold and use. It would have been nice if a hook had been included so that the controller could be hung on the tripod rightside-up instead of dangling upside-down by the coiled cable.

Following the initial (daytime) setup, the rest of the alignment has to be done at night and every night you want to observe, assuming you want to use the GO-TO computer to locate objects for you or even just to track objects in RA.

First night with the Autostar:

I spent about one hour trying to polar align and GO-TO M42 in Orion. This was a very frustrating experience, and now I understand why some other ETX-90EC Autostar users have complained so loudly. But lets begin at the beginning.

I decided to try the Polar Align Mode first since the Meade Tripod was already set up for Polar Mode. I went through all the initial setups of entering the current date, time, etc., and then went into the Polar Alignment Mode. The help display on the Autostar said to put the ETX into the "home" position, which it described as rotating the ETX in RA until the "smaller fork" was over the control panel on the ETX base. "Smaller fork"? I couldn't see much difference in the size of the left and right forks. So I decided to try putting one of the forks over the control panel and seeing what would happen. To make a long story short, it didn't work. OK, try the other fork. Still, it didn't work. OK, think through it logically, I decide. Point the ETX at Polaris, with the eyepiece on top, which I decide is a natural position. Try a two-star alignment. Pick Polaris. Close. Select Sirius. Oops, ETX ends up pointed 45 degrees to the east of Sirius. Slew it manually using the Autostar controller buttons until Sirius is centered in the eyepiece. OK, perhaps I'm close enough to try for M42 in Orion. Select M42 in the Autostar and GO-TO. Oops, it thinks M42 is east of Sirius. So, I decide to start over. Re-do the polar alignment. Tried really hard to get Polaris centered as the first of the two-star alignment. Select Sirius as the 2nd star; the Autostar got close so I centered it. GO-TO M42; oops, ETX ends up pointed downward and 180 degrees from M42. I give up in frustration and decide to try again after a few days (after I calm down).

In the meantime, Meade released a revised Autostar manual and an ETX and Autostar FAQ on their web site. I print the pages and read them thoroughly. I learned that my guess on the proper home position was correct. And there was a lot of other new material that clarified the operation of the Autostar. So, armed with new insights and confidence I waited for the next clear night to try another Polar Alignment and GO-TO test.

That night finally arrived and in order to start over properly I redid the motor calibrations and drive training, location setting, and checked all the other settings (they were correct). And then I set the ETX in the Polar Home position. I even carefully leveled and aligned the tripod. I then selected a two-star alignment, selected Sirius and the ETX slewed to near Sirius (but didn't get it in the finderscope). I manually centered Sirius using the Autostar controls. Next I picked Betelgeuse, figuring that would be simple for the Autostar to locate. But the ETX slewed about 180 degrees past Betelgeuse. So I try the Easy Align. The Autostar picked Sirius and this time it actually ended up in the finderscope! Then the Autostar picked Alioth (in the Big Dipper) and that ended up in the finderscope. Yippee! So, now the test -- GO-TO M42 in Orion. Oops, the Autostar thinks that M42 is below the horizon.

So now I'm convinced that the Polar Align Mode has some problems, or at least is not as easy as finding objects manually using sky charts! So, I change the Meade Tripod to the Alt/Az mode and put the ETX in the Alt/Az Home position. Since my frustration level was increasing I decided to try the Easy Align first. The Autostar selected Sirius and it slewed Sirius into the finderscope. Yea! I used the Autostar controls to manually center Sirius in the eyepiece. Next, the Autostar selected Capella and slewed to put it at the edge of the finderscope's field-of-view. I centered it. Now the test: GO-TO M42 in Orion. The ETX slewed to put M42 about halfway to the edge of the finderscope field-of-view!! This was my first successful GO-TO so I was pleased. I then selected to GO-TO the Pleiades, which again was in the finderscope. By now, clouds were coming in so further attempts were limited to just trying Sirius and M42, which always ended up about halfway to the edge of the finderscope field-of-view. This would not be good enough for faint or small objects so it was obvious that I needed to practice more with the Autostar and aligning. But at least I have learned that using the ETX-90EC and Autostar (with software version 1.0c) in the Alt/Az mode is likely to be the most successful mode of operation for the beginner and less prone to whatever errors can occur when attempting to use them in the Polar Mode. And I should note that RA tracking in the Alt/Az mode was excellent.

My second night with the Autostar was less successful. I setup the ETX in the Alt/Az Home Position and tried for an Easy Align. The Autostar selected Sirius and slewed it to the edge of the finderscope field-of-view (similar to the previous night's experiences so I figure I'm getting some consistency). I slew to center Sirius. It then selects Alioth, which is behind an obstruction. So I start over. I put the ETX in the Home Position, Autostar selects Sirius, which ends up in the same position in the finderscope and I center it. Again, the Autostar selects Alioth but this time I decide to make it select another 2nd star by using the up/down scroll arrows on the controller. I continue to scroll "down" though the list but I couldn't get past Mizar (which was also behind an obstruction). No problem, I think. I'll just scroll back up through the list. Nope, the Autostar is stuck on Mizar. Start over (again) by putting the ETX in the Home Position. Autostar selects Sirius but this time it doesn't get it in the finderscope. I slew to center it. Then the Autostar selected Capella, but I decide to scroll "up" to manually select another star. I get to Mizar and get stuck again. Must be a software bug. OK, move telescope so that I can use Mizar and start over once again. Put ETX in the...; well, you know the drill. Autostar selects but does not get Sirius in the finder; I get it there. Autostar selects Capella but I scroll to Mizar (I want that star now that I moved the ETX to see it!). Some star was placed in the finderscope but I could not confirm that it was the right star due to sky brightness. But it was the only star in the field-of-view so I "trust" the Autostar. Now came the test; see if the Autostar can locate Venus, which was still above the horizon (although it was further above the horizon 30 minutes ago when I started the first alignment). The ETX slews to near Venus but was off by 5 degrees in both RA and DEC. And now Venus is disappearing behind the trees. OK, lets GO-TO the Moon, which is riding high in the western sky. Again, the position was off. So I deduce that my easy align was off. But now the fog is coming in so I can't start over and do another alignment tonight and rain is forecast for tomorrow night.

On my third night out I used the ETX-90EC and Autostar from inside the Clear Night Products TeleDome portable observatory. Being inside this observatory limited my ability to do a perfect alignment but I figured I would try it anyway. I set the ETX in the Alt/Az Home Position, approximately pointed north since I couldn't actually see Polaris due to the observatory wall and the bright moonlight hampering seeing stars. I then selected to do a Two Star alignment. I picked Betelgeuse as the first star. The Autostar didn't get it in the finderscope's field-of-view so I found and centered it manually using the Autostar slewing controls. I then selected Sirius; again the Autostar did not get it in the finderscope so I found and centered it manually. Then I asked for M42 in Orion and the Autostar got it within the 26mm eyepiece field-of-view! I then asked for Venus and the Autostar got it within the finderscope. Not bad for such a short distance two-star alignment. I then put the Autostar to sleep for about one hour while waiting for the Moon to rise higher in the sky. "Sleep" is a battery saving mode that keeps the clock (but not drive) running. After the hour I turned the Autostar on and selected to GO-TO the Moon. The Autostar put the Moon in the finderscope. Pretty good considering my imperfect alignment tonight.

Now I need to wait for the weather to stay clear and for the moon to get out of the sky so that I can try some faint objects. Stay tuned for further updates as I work more with the ETX-90EC and Autostar. But based upon my initial experiences and those of many other users, there are operational aspects of setting up and using the Autostar that may prevent it from working as well as expected. On the other hand, many other users have reported very positive results in both the Polar and Alt/Az Modes. And as I've noted here, some nights you may get bad results and other nights you will get pretty good successes. Whether the problems are a result of Autostar software bugs or just operator luck remains to be seen. At the time I was doing these tests, Meade was expected to release an update to the Autostar software on their web site. The new release (v1.1) is now available and I will update my Autostar when I receive a serial cable. Stay tuned...

Until all users can report positive results "out of the box", adding the Autostar Computer Controller is a gamble that may result in the wonderful thrill of seeing many astronomical objects with a minimum of effort or it may result in total frustration. But there should not be any hesitancy about purchasing the standard ETX-90EC. It remains an optically fine astronomical instrument, and with the addition of the motorized controls will give even the casual amateur astronomer many hours of viewing pleasure.

Side comment on selecting alignment stars. I don't know what geometry the Autostar uses for its calculations but some thought should be used when either manually selecting alignment stars or accepting the Autostar's selections. Dr. Leon Palmer from Rigel Systems reminded me that the Pole area is one of the worst places to select an alignment star because of the convergence of the RA lines at the higher declinations. This convergence means that a small error in angular position translates to a large error in the right ascension value. Errors in position are compounded and can even result in an opposite alignment when trying to align on Polaris, which isn't precisely at 90 degrees declination. Dr. Palmer advises to use stars that are about 90 degrees (6 hours) apart and near or on the celestial equator for the best results. Perhaps not selecting proper alignment stars is a major factor in the user reports (mine included) of Autostar failures.

ETX-90EC While waiting for the weather to clear, one day I noticed that the OTA was pointed downward and touching the base. Thinking that maybe I had left it that way for some reason I unlocked the DEC Lock, moved the OTA back to horizontal, and relocked the DEC axis. The OTA then proceeded to rotate downward on its own. The DEC lock was snug and had never been "overtightened". No amount of playing with the DEC Lock would secure the OTA in position. It appeared that something had failed in the DEC locking mechanism.

Since this made the telescope unusable, I contacted Meade about the situation on a Thursday morning at 8:33am (their time). I reached a recording that stated that normal business hours were 8:30am to 4:30pm. I guess they were late to work that morning. The message said I would be contacted within 24 hours so I left a voicemail message describing the problem and asking for troubleshooting details. I received a call back about 10am Friday morning on my voicemail. It said to call back to Meade but provided no details other than the technician's first name (Mike) and phone number. So I called back at 10:50am, found out that Mike Lee was telecommuting that day. I elected to leave a message for him. Later on Friday I received a second call from Mike Lee. Unfortunately, it was another voicemail with no answers to my question. I called back to Meade, ended up on hold for 5 minutes, and then was transferred to someone else's voicemail. So I left another message to be passed to Mike. Obviously this is an inefficient way to handle troubleshooting.

<Begin Editorial Comment>
If voicemail tag is to be done, at least there should be some Q&A occurring. My concern here is that since the ETX line seems more targeted to the mass market consumer than their larger scopes, Meade is likely to need to step up to handling an increasing number of technical support calls with more interactivity. Of course, today's consumer is probably going to have email, which can easily lend itself to a Q&A interchange. But unfortunately Meade doesn't use email to communicate with its customers.
<End Editorial Comment>

Late on Friday I heard from Meade that it sounded like the Right Tube Adapter had failed. It was stated that this would be an easy repair and should only take a few minutes to replace the part. I received the replacement part a week later. As it did not include installation instructions I assume this is not normally a user-replaceable part. I used the Scopetronix ETX/EC Tune-up page to see what might be involved; it was actually very simple. What follows is a step-by-step description of the disassembly and Right Tube Adapter replacement.

  1. ETX-90EC It was first necessary to remove the ETX OTA from the fork mount. This is done using the large allen key supplied with the ETX (see photo on the left). Unfortunately, the ETX-90EC I received from Meade lacked this large key so I used the one from my original ETX model. As noted on the Scopetronix site, you must spread the fork arms outward away from the OTA to allow the tube to slide rearward out of the fork. The photo on the right shows the ETX OTA removed, the empty fork mount, and the screws and allen key. ETX-90EC
  2. Next completely unscrew the DEC Lock knob and remove it as shown in the photo here.
  3. Slide the old Right Tube Adapter out of the right fork arm.
  4. Remove the gear from the old adapter and place it on the new adapter.
  5. Reverse the steps above. I did have some initial difficulty getting the ETX OTA back in the proper position on the tube adapters but with a little fiddling the alignment was made. One tip: don't lock the DEC axis or you may shear your new Right Tube Adapter trying to align the adapters and the OTA.
That's it!

ETX-90EC Once I removed the failed adapter it was easy to see why the DEC Lock would not lock the ETX in declination. The plastic shaft had sheared off. The photo on the right shows the old Right Tube Adapter (left) and the new one (right). The sheared off portion of the shaft is laying on the old adapter. There have been several reports of this type of failure on the ETX Mailing List and other reports posted on the ETX-90EC Feedback pages. The ETX-90EC manual cautions against overtightening but I know I never did what I could call "overtightening". And it failed while the ETX was not in ETX-90EC use. This failure mode has been addressed by Meade. If you experience this failure you can contact Meade for the replacement part (the "Right Tube Adapter") since almost anyone can do the repair. There is no need to return your scope (with all the shipping charges) to Meade.

I recently received the serial cable from Meade to update the Autostar software. See my report on the Autostar Information page.

See my updated report for additional comments.

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Copyright ©1999 Michael L. Weasner / etx@me.com
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