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Meade Maksutov Cassegrain 7” (178mm) LX200 f15 OTA

Posted by Steven Keaton   07/01/2005 07:00AM

After 2 years, I’m already on my 7th scope. Like most everyone else, I have tried to find the perfect balance between, apeture, focal length, performance, portability, and of course, . . . cost.

Introducing, a great sleeper, the Meade Maksutov Cassegrain 7” (178mm) OTA with Ultra High Transmission Coatings (UHTC).

I started out at the end of May 2003 with two little Maksutov Cassegrains of 90mm and 125mm apertures. Then I moved up to an 8” SCT. Now we were getting somewhere. Seven months later I succumbed to the APO refractor bug. Two of those, first a 102mm, next 128mm and then another CAT, sized 9.25” and then . . . then I began to remember the great crisp views I was getting from my original two Maksutov Cassegrains.

Since I had become so fond of high end optics, and was missing the quality of every little detail found in my two APO’s, and craving bigger apeture as well as longer focal lengths, I turned my attention to Maksutov Cassegrains again. I was very seriously considering two high end Maks in the 8 and 9 inch range. I was very close to ordering a highly respected 8 inch when I began to remember some rather positive remarks about the Meade LX200 7” Maksutov Cassegrain. I began to read everything I could find on this scope. It only made good economic sense to test the waters with a scope that came in at a third of the cost of a very well respected 8” Mak/Cass.

It was an easy decision to purchase the Meade LX200 Mak OTA after reading so much good about it. So Mid-April 2005, I bought the OTA from Anacortes. I made the phone transaction on Tuesday and it arrived on Saturday. It would be appropriate at this moment to mention that this is the OTA only. It does not come with a viewfinder and rings, or a visual back of any kind, and finally, no diagonal or eyepiece. It does come with a Meade dovetail plate and some type of saddle, but I quickly replaced that with a Losmandy dovetail plate for use with my G-11.

The OTA arrived in pristine condition and the optics under a visual inspection looked great. Some have complained about excessive dust on the Meniscus, but I could not detect any, and as later visual observing proved, there was none noted. As far as fit and finish are concerned, practically everything is metal, and everything arrived in excellent condition. There is a handle at the back, fitted horizontally, and ½ inch from the bottom of the back plate. Its placement was well thought out. It makes mounting the OTA very easy. Although it seems possible, I have not tried carrying or lifting the OTA by just the handle. I always cradle it with one hand and hold the handle with the other hand.

Now for a detailed description. . . . . .

A steeply curved 7” spherical-meniscus correcting lens made of Grade-A Crown BK7
optical glass.
The primary mirror is made of Fine-Annealed Pyrex glass and is 8.25”, most likely
contributing to the wider field of view than would be expected for a scope with such
a long focal length of 2670mm (f/15).

The OTA alone is about 20” long by 9” in diameter. It is a bit of a beast weighing in at
approximately 25 lbs.

There are two 18 volt fans that are well filtered, dropping cooldown time to a bare
minimum. However, the OTA does not come with a power cord. You will need to
buy an 18 volt power source with the right connector. This is easily obtained at
any Radio Shack. Be forwarned, I spent two months looking for this accessory to
power the fans. Cost is minimal though, under $20.00.

Of course, on the day it arrived, it was raining, and did so for days. This was a fine opportunity to check out the scope and its condition as mentioned earlier. I took off the Meade dovetail plate and replaced it with a Losmandy designed for this OTA. Matchup went smooth without a hitch. This setup looks like it means business.

I use a Televue SCT adapter that mates to my Williams Optics diagonal. I have put this scope through extensive use, employing four Nagler eyepieces. A 26mm T5, a 17mm T4, a 12mm T4 and a 9mm T6, and most recently for fun a Televue 55mm Plossl. I seem to use the 17mm most of all. It yields enough magnification of 157X while still allowing for a favorably sized field of view of .522. The 12mm seems to push the power of the scope just a bit, sometimes causing a softer view with a washing out effect, but I attribute a lot of this to the area I live in, Northern, KY where the Jet Stream loves to wreak havoc on those of us just dying for a real true clear evening. However, on good nights of seeing, this eyepiece does wonders at 223X. It just seems that going over 200X here in Northern, KY with any scope that I have owned creates this appearance. And finally, the 26mm at 103X is a gem of an eyepiece, just barely allowing a full moon to fit inside the field of view while causing temporary blindness.

About Performance:
Jupiter and Saturn are seen as spheres instead of flat discs, even approaching 3D appearance on evenings of good seeing. On Jupiter the GRS comes into view with activity shown. Under good seeing, white ovals are available for viewing. The four principle moons show some color and size differences, although slight.

Saturn is always a treasure to view. Of course the Cassini division is readily seen, with the rings showing color variation. The planet itself shows good color contrasts.

M42 always an easy target has shown more detail than I have ever seen. Its appearance is huge in this scope.

The moon of course is jawdropping. Crater and Mountain detail is astounding. I have never enjoyed viewing the moon in another scope as I do this one. On one particular evening, with a new moon just about 2-3 days old, I caught such a view with the 26mm Nagler. It appeared that I was hovering over the moon, or more specifically, coming in for a landing. My wife even came out for this view and concurred.

On deep space, you will see a nice black backdrop that reminds me of what I would see in two other high end APO’s that I have owned. This scope really seems to be refractor like.

A word of caution though, this is not a light scope. The OTA with the my usual bare necessities of a Losmandy dovetail plate, Viewfinder, WO 2” Diagonal and a 2” Nagler cause this set-up to weigh in at 29.5 lbs. give or take a few ounces. I recently added a Williams Optics Crayford design manual Fine-focuser which adds even more weight. Therefore, it is not for the faint of heart. It is always a bit nerve racking to set this on top of my G-11. And since so much weight is concentrated in the back, I find it easier to slide the Dovetail Plate into the saddle from the top down through the saddle.

Pros: Great views. Crisp, sharp, allowing for fine detail that is truly refractor-like.
Nice dark background.
Minimal cost in comparison with any APO of like aperture.
Attractive design that is understated, but means business.

Cons: A bit heavy, but manageable.
Cooldown required, (without cooldown you get those looking through gasoline views,
tube currents, etc.), but cooldown is facilitated by two filtered fans.
Primary optics openly exposed to elements, subject to dust and dew.
Must provide own power source for the fans.

Overall though, I am quite pleased with this scope and will only replace it with a higher quality Maksutov Cassegrain. Of course, I recommend this scope to anyone who is looking for higher magnification and a little more aperture while still having a portable scope and some money left over for some high end eyepieces and fancy accessories.

Thanks for reading,

Steve Keaton

Click here for more about this subject. -Ed.