Last updated: 3 April 2000

This is a continuation of my earlier reports on the ETX-125EC and Autostar. Two earlier reports (Part 1 and Part 2) were actually limited comparisons of the ETX-125EC and NexStar5. A third report was the beginning of what will be an extended report on the ETX-125EC as I use it. If you have not read that report please do so before continuing with this one.

I should note right off that the Autostar was loaded with a beta of some indeterminate version (it doesn't match any recently released version other than being version 2.x). So some of what I have to say about the Autostar usage may or may not be applicable to all users. The Meade AC Adapter was used for all ETX-125EC observing sessions, as well the Meade Deluxe Field Tripod (with the included adapter plate).

"First light" for the ETX-125EC occurred on 11 March, when the clouds and rains that had been in my area since getting the telescope on 10 February finally went away. I took the telescope outside, plugged in the power adapter, and started to put the ETX in the Home position. I discovered the DEC scale knob was very loose and the DEC scale was off by about 45°. This was easy to fix but I was surprised by it. The ETX was mounted in Alt/Az mode. Having previously trained the drives, I proceeded to do an Easy Two Star alignment. Sirius was placed just outside the finderscope field-of-view (FOV) and then Aldebaran was at the edge of the finder FOV. With both stars centered, the alignment was declared successful.

I then did a GOTO Jupiter, which was low in the western sky. It was placed centered in the 26mm eyepiece (I was pleased at that). But then I discovered something that had not been evident in my earlier ETX-125EC usage. With the ETX pointed west and low in altitude there was considerable movement in altitude. Just the slightest touch on the ETX-125ECfocus knob, tube, or forks would send the image up and down. While observing Jupiter with the 26mm eyepiece, the movement was several Jupiter diameters. There was almost NO movement in azimuth. I realized that the OTA was essentially perpendicular to a line through the tripod/plate mounting bolts and therefore possibly lacking some support in a east/west direction. I decided to see what happened if the ETX was pointed south. Guess what? The movement was now in azimuth and very little in altitude. I then pointed the ETX high in altitude but westerly; very little movement in altitude or azimuth. Conclusion: there was insufficient lateral support on the base perpendicular to the line between the mounting bolts. The bolts were as tight as I dared make them. In an attempt to add some support and increase the pressure on the plate I attached two metal "spacers" as shown in the photo on the right. This reduced the bounce significantly but did not eliminate it. Since this problem was not evident on a different ETX-125EC and tripod combination I currrently do not know what is at fault. I continue to investigate this.

I then did a GOTO Saturn. It was placed in the 26mm eyepiece FOV. Unfortunately, it was so low in the sky that no details other than the disk and rings were discernable.

Next up was M42 in Orion. The Autostar placed it just offcenter of the 26mm eyepiece. Definitely a beautiful sight. Then it was Sirius for a ETX-125EC collimation test. The photo on the right (done with a Ricoh RDC-4200 digital camera mounted using a Scopetronix Digital Camera Adapter) shows the rings that were visible on one side of the focus run (disregard the black spot artifacts). As I ran the focus from one side of exact focus to the other out-of-focus side, the rings would shrink to a point and then expand back to what you see here. The symmetrical rings shows that the optics were in collimation.

Then it was on to the Pleiades, M45. The Autostar got them centered in the 26mm eyepiece. Pretty sight.

Then GOTO the nearly First Quarter Moon; oops just slightly outside the 26mm EP FOV. I then proceeded to take some pictures of the Moon (shown on the Astrophotography Gallery - The Moon page).

From this first light night I was able to determine that the optics were excellent on this randomly selected ETX-125EC, with no collimation errors and no image shifting during focusing. In addition, I did not experience any drive gear backlash problems. While there was some slack in the "takeup" as direction was changed, it was neither excessive nor annoying. I do wish the tripod/plate/base combination had provided a more stable platform.

ETX-125EC For the second night out I had attached a Scopetronix FlexiFocus in place of the standard focus knob. Initially I could not get the standard knob removed because I thought I did not have the right size allen wrench. The two that came with the ETX-125EC were too small. Fortunately, after a brief confirmation from Jordan Blessing at Scopetronix, I determined that I did in fact have the proper wrench; I was just not inserting it far enough into the setscrew hole! With that problem solved, the FlexiFocus attached easily (see photo on the right). In use, I found that the FlexiFocus does reduce the hand-induced vibrations during focusing. And with the altitude bouncing problem I was experiencing, anything that reduces the vibrations helps a LOT. It was nice to not have to bring my hand so close to the telescope to focus. Yes, an electronic focus would be nicer but the FlexiFocus does almost as good for less cost. With a sturdier mount, I suspect that the FlexiFocus will really demonstrate its value. I have left the FlexiFocus attached for subsequent sessions because I like it.

On another night I did some eyepiece comparisons. Although Jupiter and Saturn were low in the west I used them as targets. Here are the results:

26mm (73x) = Good image quality.
26mm + 2x Barlow Lens (146x) = Good image quality.
9.7mm (196x) = Good image quality.
9.7mm + 2x Barlow Lens (392) = Poor (too much atmospheric interference).

26mm (73x) = Good image quality.
26mm + 2x Barlow Lens (146x) = Good image quality.
9.7mm (196x) = Good image quality.
9.7mm + 2x Barlow Lens (392) = Poor (too much atmospheric interference).

Then I aimed at M42 in Orion and then the Pleiades:

40mm (48x) = Lots of details and extent.
40mm + Wide Field Adapter = Not as nice as the 40mm alone.
26mm + Wide Field Adapter = Similar to 40mm alone but less contrast.

40mm + Wide Field Adapter = Very nice. All seven of the brightest stars were in the field-of-view. There was some image distortion however.

And then the fog rolled in. Rats.

As noted earlier, I will continue to add more reports as I continue to use the ETX-125EC. For now I can say that the optics are great. The Meade Deluxe Tripod needs some modifications to be a good stable platform for the -125, or a different mount used.

Watch for more reports. Now that the Moon is leaving the evening sky I hope to work on Deep Space Objects and Double Stars (weather and time permitting).

Another night's session. This time I attached the ETX-125EC to the Meade tripod using the newly received Shutan Easy-Mount. This produced a more stable mount but there was still some bounce as described earlier. When tapping a fork or the tube the vibrations would dampen out within 2 seconds. Using the Scopetronix FlexiFocus really helped.

For the first time I noticed a very slight focus shift when changing from the zenith to horizontal. If focused in the middle range (from a 45 degree altitude orientation) I would not have even noticed it, which is probably why I hadn't seen it before.

This night I took a quick look at Castor. Nice. Then chose a few objects from "Tonight's Best" Guided Tour. Several star clusters (beautiful in the 26mm eyepiece) and a couple of galaxies. One (I didn't bother with writing its name down for this quick session), was Magnitude 9.1, which is rather faint for my location. But the Autostar centered it in the 26mm eyepiece and it was easily seen. All objects I went to were either centered or well within the 26mm eyepiece FOV.

All in all, a nice quick fun session.

On Friday, 31 March, I had a chance to do some more observations. I setup in my yard instead of on my concrete patio and nearly all the vibrations went away. So, a softer surface, whether using the Celestron Vibration Suppression Pads or just grass/dirt, helps a lot.

I had also set up the ETX-90RA so that my wife could make drawings of some objects using it. I took advantage of this to compare M42 (the Great Nebula in Orion) in the two scopes. I used the 26mm eyepiece in both telescopes (48x with the -90 and 73x with the -125) since that is the standard eyepiece supplied with each telescope. As to be expected, there was more nebulosity visible in the larger -125; wisps of nebulosity could be seen much further out than with the -90. In addition, the nebulosity stood out better from the sky background in the -125. While M42 is impressive in the -90, it is really impressive in the -125.

Side comment: the Scopetronix Microstar II+ in my ETX-90RA really tracked well. It kept M42 completely centered during the time that I brought the -125 outide, set it up, aligned the Autostar, and got M42, and then as I moved back and forth from one scope to the other. The Autostar on the ETX-125EC kept M42 centered as well.

I then let the Autostar show me some objects. First up was Spindle Galaxy, Caldwell 53, magnitude 9.1. This was the object I had seen on an earlier night but failed to write down. It appeared as a small faint fuzzy object. But it was there, centered in the eyepiece by the Autostar. Then to the very nice double star Almaak, mag 2.2 (brighter star) with a very close (approximately 10" separation) but much fainter (mag 5) companion star. There was no drive-induced vibration so the stars were split with the 26mm eyepiece. Then on to the Crab Nebula, M1, magnitude 9, a fuzzy patch, which was seen with averted vision. Then the Eskimo Nebula, mag 8.3, and the Ghost of Jupiter Nebula, mag 8.6, both planetary nebulae and both very nice, especially "Jupiter". Then two spiral galaxies, NGC 2903, mag 8.8, seen with averted vision, and M81, mag 6.9, which was easily seen. Lastly, an irregular galaxy, M82, mag 8.3, another small fuzzy but distinctly elongated patch.

In general, the Autostar placed all objects at or very near the center of the 26mm eyepiece field of view. Even though I did this observing session over about 1.5 hours, no adjustments to the Autostar alignment were necessary.

I must say that having the Autostar perform so well does take the challenge out of finding objects but it definitely adds to the fun of astronomy by making objects so easily seen. And lastly, I believe this ETX-125EC must have some better noise suppression on the drive motors as it seems somewhat quieter than I remember from the earlier evaluation unit. It is not annoying at all. I am definitely enjoying using the ETX-125EC and Autostar.

While playing around with the Autostar, I looked up (for some reason) and almost at the zenith was an Iridium flash. That is the first one I have seen. It was brighter than Sirius but faded quickly. (I suppose it was an Iridium even though the Heavens-Above satellite prediction site does not show it. Alternatively, it could have been a straight-on meteor.)

I'll add more reports as I continue to use the ETX-125EC.

I had intended that the above would be the last update for this edition of the page but events Sunday night, the 2nd of April, changed my mind. Here's what happened:

Had some family visiting so decided to show them some stuff through the ETX-125EC. Based upon my previous good experiences, I bragged somewhat about the Autostar. Entered the date/time and selected Daylight Savings since we had the time change. Did an Easy Align, as I had done in the past. It was declared successful. GOTO Jupiter; oops, where is it? Not in the eyepiece, not in the finderscope. Oh there it is, several degrees away. Lousy way to start. GOTO Saturn; same results. So, thinking maybe I really didn't have Daylight Savings Time set, I powered off and on and redid everything. Yep, DST was set. Easy Aligned OK. GOTO Jupiter; in finderscope FOV (whew). Then GOTO Saturn; in finderscope FOV. While one of my guests was looking at Saturn, the scope decided to slew several degrees away from Saturn! This is the first time it has ever happened to me and it had to happen with guests!!! After I got things back under control, we finished with Saturn. GOTO M42; missed by several degrees. Manually centered it. Then GOTO Pleiades; missed by several degrees so manually centered. Then time ran out and I decided more challenging objects would not have been appreciated. Fortunately, my guests were impressed by the objects they saw.

Two things were different on this night from the previous highly successful nights. One, there was the time change. Maybe that affected the calculations somehow. Did anyone else experience a similar problem with pointing after the time change? Two, I had placed the Autostar handcontroller on the Easy-Mount extension so it was sitting right next to the base. Previously, I was either holding the Autostar or it was attached to a tripod leg using some velcro I had there. So could there be some RFI from the handcontroller? Anyone have an opinion or experience with the random slew and handcontroller position?

Stay tuned...

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