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Meade ETX-125 UHTC

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Let’s get the formalities out of the way first: I do not have any commercial interest in Meade, Orion or any of their distributors.

I’m approaching this review from two perspectives: To look at the ETX 125 on it’s own merits and then as an upgrade from an Orion 90mm EQ achromatic refractor.

My observing experience and location also have a strong influence on my perspective. I’ve been interested in astronomy since I was a kid (a “lightie” in local parlance) but only started observing actively from my light polluted, coastal, suburban backyard about 6 years ago. My first telescope was an Orion 90mm refractor on an EQ-2 mount, this has now been replaced by the ETX 125.

Here in sunny South Africa we are blessed with clear and relatively dark skies, southern hemisphere astronomical showpieces and balmy evening temperatures. Despite these ideal conditions, astronomy is very much a fringe activity and amateur astronomers and their telescopes are few and far between. Two reasons for this are the paucity of local telescope retailers, and the markup on equipment is generally very high - doubling the US$ cost (local price of an ETX 125 without UHTC is over $2,100!).

Observing with the Meade ETX 125 UHTC

You are going to have to excuse some initial gushing here, but sometimes you walk in from an observing session with the ETX 125 and you just think – wow!
This is a stunning little telescope. It’s the kind of thing that you sit and fiddle with on a Saturday afternoon because it’s simply fun to do so.

My ETX 125 is the nicest telescope I’ve ever looked through. At ScopeX 2004, the annual ASSA (Astronomical Society of Southern Africa) telescope exhibition held in Johannesburg in late April, I had a continuous queue of about 20 people waiting to view Jupiter (with a borrowed 15mm Meade Plossl and 2x Barlow giving 250x magnification), the longest behind any telescope. With an assortment of scopes nearby (including a C8, LX90, various Dobs and small refractors), I was told by many that the view of Jupiter through the ETX was the best at the star party.

With its f/15 focal ratio and 1900mm focal length, the ETX 125 would seem to be a specialist lunar and planetary scope. It certainly excels on the Moon and planets with sharp, colour free and detailed views but with the standard 26mm Plossl (73x), open clusters and globular clusters are also easy and satisfying targets. It is reported in the Cloudynights ETX forum that the ETX 125 loves Konigs and Erfles which have wider fields than Plossls – I’ll have to start saving…

To UHTC or not to UHTC?

Not having looked through an ETX 125 without UHTC (Ultra High Transmission Coatings), I can’t personally comment on how much of an improvement it makes – having said that I must say that the views through my ETX are stunning and I feel that the UHTC has to be contributing towards this. UHTC has been reported to give a 10 – 15% improvement (Cloudynights Report, 7” Meade MCTs) in subjective visual testing, and a better than 20% improvement (Arkansas Sky Observatory, 10” Meade SCTs) in measured light throughput, so it does seem to be worth the 10% extra expense.Using the ETX 125

Mechanically, the fork mount and tripod combination seem well suited to the size of the OTA. Dampening time after vibrations, even at high power (250x), is quick. The plastic outer shell on the metal fork mount initially doesn’t inspire confidence, but in actual use the fork mount is quite stable and the Alt-Az operation always places the eyepiece and finder in a comfortable viewing position. I haven’t tried the mount in equatorial mode yet as I haven’t found the need to.

The motors seem noisy when slewing at 3 a.m. but from 10 metres away, you realize that they aren’t all that loud. A “Quiet Mode” reduces the slewing rate (and thus the noise) if the neighbours start to get rebellious. Tracking is visually smooth and accurate.

The full system on the tripod can be carried in one arm and as such is very portable.

The Autostar hand controller has a relatively shallow learning curve but reading the manual is still advised. It is easy to find objects by name or by Messier, Caldwell, NGC or IC number. Before slewing to a target the Autostar will tell you it’s magnitude, position and in which constellation it is. This is very helpful, especially when many potential targets are lost in the light pollution to my South, or the trees and house to my North and West.

The “Tonight’s Best” guided tour presents objects that I had either never thought of looking for (47 Tucanae – wow!) or had never found before (the Lagoon Nebula and the Teapot in the same field at 73x – wow again!). A 15-minute quick look can easily turn into a 2 or 3 hour observing session due to the convenience of the Autostar

The ETX requires some effort and attention to detail to get it working well. Before starting an observing session you need to calibrate the motors and then train them to compensate for lag and backlash. The mount has to be level and true North aligned and the tube must be leveled before you start the alignment procedure. The more accurately you complete the manual setup, the more accurate subsequent alignment and GOTO results will be.

So far it’s been all wine and roses but the ETX is not without it’s faults. The major observing bugbear on mine was the random “Motor Unit Fault” error that occurred during tracking and then requires the resetting and realignment of the telescope to continue. I won’t bore you with the potential causes and solutions, but this has been an intermittent fault with the ETX line since it was introduced nearly 10 years ago and it occurred frequently enough on my scope to be more than a minor irritation. In my case, replacement of the RA drive (see below) has solved this.

Two glaring omissions from the ETX package are a dew shield and a bracket to hold the Autostar controller. The corrector lens dews up rather quickly and although I have made a temporary dew shield with black cardboard which works effectively, it won’t win any prizes for elegance. The dew shield also stops stray light from shining onto the corrector and reducing contrast - a major issue for any backyard observer. A decent dew shield is essential for grtting the best performance out of the telescope and is highly recommended.

The lack of bracket for the Autostar handbox is a silly oversight by Meade, especially on a premium range such as the ETX series.

The top element of the supplied 26mm Plossl is recessed quite far into the barrel, forcing you to make full use of the approximately 15mm eye relief. I find I have to push the eyecup down and screw my eye into the eyepiece to get the best view. Although this is not really a problem, it is just different from my old 25mm Kellner.

Much has been written about the dinky 8x25 right angle finder that isn’t complimentary. I find it works fine for its intended purpose of centering an object that the Autostar hasn’t placed in the eyepiece field of view - common during initial alignment but seldom necessary during a GOTO observing session.

Meade UK’s Technical Support

Disaster struck quietly one Saturday evening when the Jewel Box elegantly exited the field of view. Attempts to slew in azimuth with the hand controller elicited only faint “cluck” noises from the base of the mount. To cut a long story short, the mounting holding the motor/gearbox to the worm gear assembly had snapped.
Meade UK were wonderful and within a week (and with considerable help from my brother-in-law in the UK), I had a new unit installed and the scope working again. Kudos to Meade UK (Broadhurst, Clarkson and Fuller) for their rapid and informative responses to emails and for the happy resolution of the breakdown.

The new motor unit also seems, so far, to have resolved the “Motor Unit Fault” issue as this has yet to happen since the repair.

Meade ETX 125 UHTC as an upgrade to a 90mm Orion refractor

As I’ve mentioned, we don’t get to look through a lot of different telescopes in my part of the world. My personal experience is very limited and I had little idea as to how much better the ETX (or any other telescope) would be compared to the smaller diameter Orion refractor.

The Orion 90 mm achromat (reviewed here on Cloudy Nights) is a fundamentally good telescope. The f/10 optics are good and it is mechanically simple and sound. Its biggest limitations are the relative lack of light grasp (at f/10, false colour was never really an issue) and the EQ-2 mount, which is a bit wobbly.

Is the ETX worth it’s 4x price premium?

Undoubtedly it is. Optically it is in a different league to the refractor. With colour free views that are sharper and crisper, it also takes magnification easier and is always a pleasure to look through.

While I do fondly recall the ease and rapidity with which the Orion could be set up as compared to the procedure required for the ETX, the nostalgia quickly fades as the Meade effortlessly whines it’s way quite precisely to target after target. The setup difference is only about 10 minutes in reality.

Focusing at higher magnifications is far easier and it snaps into focus with more authority than the refractor. Mechanically it is more stable and the components are of better quality, especially the tripod.

The GOTO capabilities are the cherry on top. I’ve done my time trying to find DSO’s by star hopping. I find GOTO adds a lot of fun to observing. It is also very informative as each object has brightness, distance, size and other information available on the Autostar screen, turning each observing session into an educational experience. On my first “Tonight’s Best” tour I was astounded at what was within reach of the 5” Mak, and amazed by the number of objects that were up that I’d either never heard of, or had never found before.

Photography (with the Maxview 40 eyepiece and Minolta D7i digital camera combination) in Alt-Az mode is a snap - and the results are very pleasing to me. The picture below is the very first image I took of the moon through the ETX - it has not been processed in any way except to crop and resize it to fit on the page (no sharpening, stacking, level, contrast or colour adjustment).

I haven’t mentioned collimation or cool down time, both of which can be issues with MCT’s. I don’t know much about star testing but the diffraction rings are identical on both sides of focus so I assume the optical train is aligned OK.

Nights are fairly warm (especially here on the coast in Durban), therefore cool down times are not much of an issue as the inside/outside temperatures probably don’t differ by more than 5°C on most nights. Subjectively the views do improve slightly as the observing session progresses, but the views at initial start-up are very sharp in any case so I don’t bother with a cool down period. Having said that I have had one cold night (OK, it was only 10°C) session observing the _ moon in which the image boiled noticeably at high power.

Some mirror shift can be noticed while focusing but it doesn’t detract much from the observing experience.

Meade’s $99 eyepiece offer

This arrived some four months after the ETX did due to the considerable popularity of the offer and the backlog that this created. It was worth the wait as it has extended the capabilities of the ETX considerably.

The seven eyepieces, all in bolt cases and nestled in the neat aluminium case, complete the set of Series 4000 Plossls - starting at the 40 mm and ending with the 6.4 mm. This gives a magnification range of 48x to 297x which suits the ETX well.

I haven’t managed to spend sufficient time with all the eyepieces yet to form an opinion worth sharing, but the 15 mm is already a favourite.

ETX Resources

No review of an ETX would be complete without mention of Mike Weasner’s ETX site at www.weasner.com/etx---the mother of all ETX sites. Here you will find the reference to the Arkansas Sky Observatory UHTC comparison mentioned above along with literally thousands of comments, articles and reviews covering all things ETX---accessories, imaging, alignment techniques, troubleshooting and more.

The Meade website (www.meade.com) is nowhere near as useful to ETX owners but Meade does frequently update the Autostar software. This is available for download and is uploaded to the hand controller with a serial/RJ45 cable. The ability to update is a very useful and powerful feature of the Autostar system. The same cable allows your PC to control the ETX and I have used SkyMap Pro 10 to easily do this, making for more Saturday afternoon fun!

Final thoughts

I do suspect the GOTO glow may eventually wear off, but it will be years before I become blasé about the marvelous Maksutov Cassegrain optics.

This is not a telescope for the beginner or casual observer. The ETX demands your involvement if you are to get the best out of it. Whether Meade intended it or not, the ETX is an ideal hobbyist telescope that rewards your input and fine tuning. The more you know about the ETX, the more you appreciate it’s capabilities.


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