Meade ETX90PE and ETX125PE MCTs

I should preface this by saying I downright love the ETX. I own an ETX-125PE, and although I am sometimes accused of being a "Celestron man," I bow to no one in my appreciation of Meade's small wonder.

Be that as it may, there is no doubt the ETX has weaknesses as well as strengths. What does ETX stand for, anyway? When Meade was developing this little Mak (Plate 28), the letters were an abbreviation for the MCT project name, Everybody's Telescope. By the time the wee CAT was released, it was just called ETX, but it was still meant to be everybody's telescope. Is it?

That depends. The ETX, which is currently available in 90- and 125-mm apertures, has a lot going for it, most notably the optics. There are things that can be criticized about the ETX, but its optics are not one of them. The secondary obstruction on these scopes, the percentage of the aperture diameter obscured by the secondary mirror, is high at 40% for the 125 and 30% for the 90, but contrary to expectations, contrast does not seem to have been harmed much (the secondary mirrors are not overly large but are surrounded by big cone-shaped baffles to protect against stray light). The ETX-90 and ETX-125 produce outstanding, high-contrast images. Compare the 125 side by side with a C5, and you will have no doubt the Mak produces noticeably sharper, higher-contrast planetary images. Saturn in the ETX is chock full of detail, all that can be expected of any 5-inch telescope, and the visible disk and ring features compare very favorably with what can be detected in a C11. How about the 90-mm scope? If anything, this little wonder amazes even more. Tested against a Questar 3.5-inch MCT (which costs about five times as much as the Meade), there seemed to be no difference in the images.

The latest version of Everybody's Telescope, the ETX90 PE." Credit: Image courtesy of Meade Instruments Corporation.

That does not mean it is all gravy with the ETX. Face it—at these price points ($700 and $1,000 for the 90 and 125, respectively), there is going to be a lot of plastic. That does not seem to harm either telescope's performance, but they certainly do not have an heirloom feel. You will not be passing an ETX down to your grandchildren. Also, the 90-mm is a cute little CAT, but 3^-inches of aperture will severely limit views of the deep sky in or out of light pollution. Very few of the 30,000 galaxies, nebulae, and star clusters in the telescope's included Autostar HC's library will be visible no matter how good the observing site. The 125 fares better in this regard, but more aperture means more weight (28.5 pounds vs. 21 pounds for the 90-mm). The 125 is also quite bulky. You can waltz the 125 out into your backyard assembled on its tripod, but just barely. This telescope is not much more portable than a C8.

Optically, yes, the ETXs are fantastic, but do not expect wide-field views. Even the 90-mm needs long focal length eyepieces to take in medium-size vistas. That should not be a surprise since ETX focal ratios are high in typical Mak fashion: f/13.8 for the 90-mm and f/15 for the 125. The upside here is that the long focal ratios are well suited for urban observing, allowing for medium-high magnification with comfortable, long focal length eyepieces. The comfortable higher magnifications of these long focal length CATs tend to reduce the annoying background sky glow that is visible at lower powers in any telescope in light-polluted areas.

Despite a need to keep production costs down, Meade has spent the last 10 years continually upgrading both the software and hardware on its ETXs. The original 125, for example, was merely an upsized 90. The larger OTA was too heavy for the all-plastic fork mount. Today's 125PE still appears to have a plastic fork, but that is deceptive. The plastic is only an outer skin; inside, the 125PE fork is aluminum. Both the 90PE and the 125PE use the 497 Autostar for computer control. The 497 is user upgradable over the Internet, and Meade issues frequent software updates to fix ETX problems and add ever-more features.

Other than optically, what is 90PE and 125PE performance like? The go-to on both scopes is satisfyingly accurate. That does not mean every object you request from one side of the sky to the other is always in the center of the eyepiece, but even when the 125 misses, it is not by much. As long as due care is taken in centering the go-to alignment stars the scope chooses, the ETX mount and computer get the job done. Go-to accuracy seems to be as good as or slightly better than that of the Celestron NexStar SE SCTs. The go-to alignment procedure for the ETX Premier scopes is very similar to that of the GPS-equipped Meade SCTs, even though the ETXs do not come with GPS: Place the scope in its Home position and turn it on; it does all the alignment tasks except the fine-tuning of alignment star centering. Thanks to an internal battery, the ETX Premier models keep time and date current in memory, so these items normally will not have to be reentered for subsequent go-to alignments. What about tracking? The ETX drives provide OK tracking in alt-azimuth mode but are really not up to the task of anything more than casual lunar and planetary imaging due to small random tracking "jumps" that cannot be trained out with PEC (which the ETX Autostar does feature).

One thing not good about the ETX is its nonstandard rear cell. It would have been nice if it had used the normal SCT-style rear port like Meade's earlier MCT, the LX200 7-inch. Instead, the ETXs use a built-in diagonal that limits users to 1.25-inch eyepieces. This diagonal is equipped with a flip mirror. Flip the mirror up (via a knob), and light goes up to the eyepiece. Flip it down, and it is directed out a rear port (hole) to which cameras and other "external" accessories can be attached. The ETX's model 884 Field Tripod is more difficult to judge. It is fairly steady with the 90-mm, but due to the unwise use of plastic in a few critical areas, it is not quite as good with the heavier 125-mm. One other thing: There have been complaints about is the scope's tube. The Premier ETX are available either with an Astro Tube silk-screened with color astronomical images or a standard Meade-blue OTA. Some astronomers think the Astro Tube looks gaudy, but I think it gives the little telescope even more personality than it already has. Both ETXs are of the Gregory type and therefore do not have adjustable secondaries. How are they collimated? They cannot be easily collimated by end users, but they usually do not need to be.

Accessories shipped with the ETX are, not surprisingly, minimalist and, in addition to standard UHTC coatings, are limited to a Meade Series 4000 26-mm Plossl eyepiece (which is a cut above the average imported Plossl) and a CD containing the basic edition of Meade's Autostar Suite planetarium and telescope control software. The scope can be powered by (many) AA batteries. In this case, with these small telescopes, AA batteries can actually be a welcome option. It is nice to be able to throw the ETX in the trunk of the car for use during (nonastronomy) vacations without having to pack a large 12-V DC battery pack to power it.

What are my final words on Everybody's Telescope? It is not a thing of machined beauty. It is plastic and utilitarian. Nevertheless, it has delighted thousands of observers old and new and has probably done more to introduce more people to the wonders of the night sky and CATs than any telescope that has hit the market since the original Celestron C8 rolled out in 1970.

Was this article helpful?

0 0
Telescopes Mastery

Telescopes Mastery

Through this ebook, you are going to learn what you will need to know all about the telescopes that can provide a fun and rewarding hobby for you and your family!

Get My Free Ebook


Post a comment