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Review - Meade Instruments ETX-125 Observer Telescope, page 2

Posted: 24 May 2017

First Light, Alt/Az Mounting Mode

As is a common occurrence whenever new astronomical equipment is received, "First Light" with the ETX-125 Observer telescope was delayed by clouds (and even rain) that showed up after I completed the unboxing and initial set up. But once the sky was clear again I had the opportunity to begin using the new telescope. I inserted 8 AA batteries in the telescope base and powered on the telescope. I entered the necessary "first use" settings (language, site, etc.). I did NOT Calibrate Motor or Train Drives for this initial use as I wanted to see how well the telescope performed out-of-the-box. First Light was with the telescope mounted in Alt/Az mode. I used the Magnetic Compass and selected to align to Magnetic North. When the telescope slewed to the first alignment star I aligned the red dot viewfinder and focused the 26mm (73X) eyepiece. Easy Alignment was successful. I checked the telescope collimation using the star Capella; it was perfect. The GOTO to Jupiter put the planet near the center of the eyepiece field-of-view (FOV).

While the telescope was slewing to Jupiter the "Astronomer Inside" audio clip about Jupiter was automatically played through the AudioStar speaker. The 7 and 9 keys on the keypad are used to change the audio volume. The view of Jupiter was excellent using both of the supplied eyepieces and both eyepieces were nearly parfocal. I then did a GOTO to M13 (Great Globular Cluster in Hercules). The audio description was played while slewing. M13 was placed in the 26mm eyepiece FOV (but not at the center).

I then began hunting the AudioStar menu for a way to turn off the automatic playing of the Astronomer Inside audio. It was found in Utilities > Audio Clip; just set to OnDemand instead of Automatic and the audio clip will not play while the telescope is slewing. To hear the audio clip for the object selected on the AudioStar just press the "?" key. You need to wait until slewing has stopped however; if you press "?" while the telescope is still slewing the slewing will stop.

I then viewed the galaxy M65. The GOTO placed it near the center of the 26mm eyepiece FOV. By slewing just a bit I could view the entire Leo Triplet of Galaxies (M65, M66, and NGC3628) in the 26mm eyepiece FOV (but just barely). Nice view.

On this First Light session I also did some basic astrophotography. See the next page.

First Light with the ETX-125 Observer telescope was successful and I really enjoyed using the new telescope. GOTOs in Alt/Az were good, as was tracking. The views at 73X and 196X were excellent.

On a later session I did the Guided Tour "Tonight's Best". Using 73X I viewed the following objects: Jupiter, Saturn, Omega Centauri (globular cluster), Albireo (double star), M5 (globular cluster), M4 (globular cluster), M13 (Great Globular Cluster in Hercules), M92 (globular cluster), Centaurus A (galaxy), M27 (planetary nebula), M68 (globular cluster), M51 (Whirlpool Galaxy), M82 (Cigar Galaxy), M104 (Sombrero Galaxy), Spindle Galaxy, M57 (Ring Nebula), NGC3377 (galaxy), and NGC4261 (galaxy). All objects from the guided tour were placed in the 26mm eyepiece FOV. The views of every object were excellent through the ETX-125 Observer telescope.

Polar Mounting

The included tripod can be used to polar mount the ETX-125 Observer by adjusting the "tilt plate" to your Latitude (from about 25° to 90°). Here you can see I have approximately set the mount to my Latitude (32.6°):


I say "approximately" because there is no precise alignment position pointer or single degree marks on the Latitude rod. The manual says to set your Latitude to be "just visible above the flat surface of the tripod head". For most visual purposes this should be accurate enough to get a good Polar Alignment using the AudioStar.

Figure 29 in the manual Appendix D shows the correct Polar Home Position with the telescope pointed towards the North Celestial Pole and the eyepiece on top. With the AudioStar set for Polar mounting mode I did an Easy Alignment. Initially there was a "runaway slew" when trying to center the first alignment star. I powered the ETX OFF and then back ON. The problem did not repeat and I was able to get a reasonable polar alignment. However, tracking accuracy was not very good. There would be a very slight drift, then a jump to recenter the object being viewed. This repeated for every object I viewed. Perhaps this problem could have been due to not having done a CALIBRATE MOTOR and TRAIN DRIVES. A few days later I did a CALIBRATE MOTOR and a TRAIN DRIVES using the 9.7mm eyepiece on a distant terrestrial object. That night I did some more polar mounted tests. This time there was only just a slight drift in Right Ascension and no jumping to re-center the object. So, apparently doing the CALIBRATE MOTOR and TRAIN DRIVES did help.

Depending on your Latitude, objects well below the Celestial Equator will not be reachable as the telescope tube will not get close to the base (there is a physical hard stop to prevent touching the base) when in Polar mounting.

Wi-Fi Adapter Control

I do not have a Meade Stella Wi-Fi Adapter or the Stella Access app, but I do have a Wi-Fi adapter in the observatory and I use SkySafari 5 Pro via Wi-Fi to control my 12" LX600 telescope using an Apple iPhone. I have a #505 serial cable which I have used with my older ETX AutoStar #497 handcontrollers and which is also required for the AudioStar.

The Wi-Fi adapter worked perfectly. I could control the ETX-125 Observer telescope using SkySafari 5 Pro on my iPhone 6s Plus. This is a convenient way to select and view objects in a telescope. If you have never used your smartphone or tablet to control a telescope, you should consider it.

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Go to Page 3 (Basic Astrophotography, Summary)

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