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Meade 7” LX-200GPS-SMT Review
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Meade 7” LX-200GPS-SMT Review
by Max Byerly
Features of Meade 7" LX-200GPS Maksutov-Cassegrain Telescopes:
- A 7" aperture gives galaxies detectable colors and splits the most stubborn of binary stars
- GPS alignment system with 16-channel GPS receiver
- 3.5-Megabyte flash memory
- Digital readout display
- Permanently-programmable Smart Drive
- 185-speed drive controls on both axes
- High-Precision Pointing
- 145,000-object onboard celestial software library
- Primary mirror lock
- 4-speed Zero Image-Shift Microfocuser
- Heavy-duty fork mount
- Autostar II control system with Autostar Suite Software
- Smart Mount Software
The Meade 7" Mak was first introduced in the LX50 series of telescopes in the 1990s. Later it became a part of the LX200 Classic series of telescopes. Unfortunately, it went away for a while, probably because they didn't sell as many models as the others. Then the 7" Mak came back under the LX200GPS line of telescopes. These started in 2001-2002 and became one of Meade's best series of telescopes. The 7" LX200GPS was having the same problem the previous models were, not enough sales. The reason for this was the 10" LX200GPS Schmidt-Cassegrain was priced at $100 less than the 7" Maksutov-Cassegrain model. At $2700, the 7" was a lot of money, and for 3" inches more of light gathering power and a hundred dollars less, it seemed to be a wise to go with the 10" over the 7". But quite a few were sold and were a hit to the people that would go for them. The 7" LX200GPS was discontinued around 2006 when Meade was releasing their LX200R models. The death of the 7" Mak ended there. I was fortunate to get one of the last ones ever made, and I love it.
OPTICS and the OTA
Collimation of this telescope is just like any Maksutov-Cassegrain should be. Not all Meade 7" were perfectly in collimation, but all of them were very good. And with any commercial telescope, some were better than others. Mine is a almost perfect collimation. All the diffraction rights on stars are all concentric and the secondary is perfectly centered on a out of focus star image. If your 7" LX200 / LX200GPS was out of collimation, Meade wants you to send it to them and they will adjust the collimation. But they don't tell you that there are push/pull screws at the front of the corrector plate. There are sets of allen head screws, that will slowly adjust the tilt of the entire corrector plate and adjust your collimation. So, yes, you can collimate it yourself without Meade's costly road trip of sending back to them for something they should of done in the first place.
The observations of the 7" are really surprising. All the optics have the UHTC (Ultra High Transmission Coatings) on the corrector plates. All the mirrors have be coated as well. The scope does surprising well on deep sky objects. Being that it is a Mak-Cass, the primary sweet spot is of course lunar, planetary and double star observations. The moon is astonishing during good seeing and 7" can handle the unstable atmosphere better than larger instruments on nights where the seeing is not as good as we all would like. The moon in this scope can take high power with just about any eyepiece. This scope can get you close to the moon because of it being f/15 at 2670mm. Saturn and Jupiter are also amazing. Saturn shows fine details on the clouds and the rings. It will pick up a few moons on most nights. Dark skies will obviously help in picking out the faint stuff. Jupiter always shows nice details in the cloud belts, sometimes the GRS, depending on the condition. Uranus and Neptune come in well in this scope, especially Uranus. You can resolve it as a bluish green sphere, and from dark skies, pick up a moon. Neptune is a bit difficult through any scope really. Blue disk with sometimes the brightest moon visible.
Double stars are big advantage to this scope, with objects like Epsilon Lyrae. With the f/15 optical system, this instrument is perfect for close double stars. Porrima in Virgo is almost always separated. Again, seeing and transparency are everything in astronomy. And some nights, there are not good enough to do some great observing. The companion to Antares peaks out on fine nights as well.
Deep sky objects is something that isn't expected to do well with this scope. Globular clusters and planetary nebulae are fine targets through this scope. M13, M22, and some of the other popular globulars show individual stars and you can resolve stars to the cores. Planetary nebula are nice through this too. M57, M27, Cat's Eye, Blue Snowball, and other popular nebula are nice because the scope gives around just the right power for optimal viewing of these targets. M57 through a 30mm eyepiece is breath taking and the smaller planetary nebula, stick in a 8.8mm eyepiece and they come to life. Galaxies are nice too, as long as they have some reasonable brightness and don't require a 14" just to see the core. Spiral arms are visible in M51 with dark skies and dust lanes are visible in M82 under nice conditions. Other small galaxies are well in wide field eyepieces where you can get the maximum light going to your eyes. Diffuse nebula and wider field nebula, like M17 the Swan, M20 the Trifid and M8 the Lagoon are wonderful with a 2" eyepiece. UltraBlock filters help tremendously at light polluted areas.
Contrast of the scope is like a refractor. The background through any eyepiece, at any power is jet black. 2" show a little brightness in the backgrounds, but for the most part, most eyepieces provide jet black backgrounds. Eyepieces around 30-40mm reveal powers from 75x - 90x magnification. High power eyepieces around 8.8mm provide power of around 310x. A optimal eyepiece range for this telescope is about 20-26mm. This is a good mid range that most targets have enough power, but your not losing any light from the exit pupil of the eyepiece.
Cool down time with the scope is a bit of a problem for some people. The OTA has a 8 pound iron counterweight behind the primary mirror. The reason for this is, if you don't have that in there you could not use it on a fork mount. The weight of the corrector plate would cause to just nose dive to the front without it. If you keep this scope in your garage or in your observatory, you shouldn't have a big issue with cool down because it is in air temperature. If its in your 75 degree house and you take it out in 55 degree night, it might take a while to cool down. Luckily, Meade built in cooling fans into the back behind the iron counterweight to blow air into the tube. It does have a filter in it to block dust and dirt from coming into the tube. If you keep it in the garage, cool down time will be very little. Sometimes if you need to cool it 5-10 degrees, it will take 2-3 hours for it to cool down. Sometimes longer if you are changing the temperature drastically. Its all because of that 8 pound counterweight. People take the counterweight out when they want to use it on a GEM mount, but for fork mounts, that counterweight must be in there. The tube weighs 24 pounds with the internal weight. That is deforked and blank without any other accessories is 24 pounds. When you take the weight out, its quite a light OTA.
The focuser is very smooth on the scope and has very little mirror shift in the image. The focuser can be upgraded with either a JMI or a FeatherTouch dual speed focuser. Of course, you can add one to the rear cell. The scope also has a mirror lock for imaging. During long exposure photography, you can lock that mirror so zero shift occurs during the exposure.
This scope is fork mounted and has the same fork as the 8" LX200GPS. It features GPS, Autostar II hand controller and has very accurate encoders and motors that give this scope nice accuracy in goto and nearly perfect tracking. The mount is wonderful for the 7" size, because the mount is beefy and heavy. Its extremely stable and provides the right platform for imaging and visual astronomy. The motors are a bit loud and sometimes people refer to it as being a coffee grinder sound. You can turn down the speed in which the motors turn in the Autostar II controller. The default is 8 degrees a second, and you can adjust it to whatever rate you want it to be.
COMPUTER AND ELECTRONICS
The 7” LX200GPS comes with the Autostar II system. It features 145,000 objects in the database and has many more features and functions than the regular Autostar does. Training the drives is the biggest thing in any version of Autostar that every recommends to anybody that has a Meade. This is where you set your telescope up and focus in on a telephone pole, cell phone tower, or something that is way off in the distance. Then the scope will move finely one direction and come back half way. You need to bring the scope back on the target with the hand controller. And you need to do this for both directions of the Azimuth and both directions of Altitude. This function helps your backlash of your gears and improve your goto accuracy. This should be performed about every 6 months or so, just to keep your scope finely tuned in. Or if you haven’t used the scope in a long time, training the drives wouldn’t be a bad idea. Calibrating the sensors is another function that helpful for aligning the scope. The scope will find level of the OTA, the home position, and then will slew to Polaris. Once you center Polaris, your goto to alignment stars will be far better accurate than before.
It has 5 different alignment procedures. Automatic, One Star, Two Star, Easy, and Align on Home. Automatic alignment is a big feature for Alt Az mode. The scope uses its internal Level North Technology (LNT) that finds the position of North, level of the OTA and goes to three different spots and determines the level of the tube. The computer will calculate the offset of the level of the tripod with these values to give you the best possible pointing accuracy.
One and Two Star align is where you pick the two stars you want. Pick two out of the database and the scope will go to them. You must have the scope facing north and level before you can select the ones you want. Easy align is pretty much the same thing, except it will just pick two stars for you automatically. The last is the Align on Home function and that is only used for Polar mode. It detects the home position of the mount and aligns on the celestial equator in the south when its finished.
The telescope also comes with a Zero-Image shift Microfocuser that plugs into the main control panel. This accessory attaches to the rear cell and accepts 2” diagonals and accessories. The microfocuser is controlled using the Autostar II hand controller and it has 4 different speeds; Fast, Medium, Slow, and Fine. This accessory is perfect for high power observations that require fine focuser without the need to touch the scope or when your doing photography of any kind.
REPAIRS AND CUSTOMER SERVICE
Meade Instruments will not service the 7” LX200GPS anymore. If you try to call and get help from them, you will not be able to get your telescope serviced if its needs a new RA motor, or control board. They claim that it has different internal parts, and thats not true. The only thing that is different is the OTA. The mount is the same one that uses the 8” LX200GPS / ACF. All the motors and everything else is the same. There are people that repair them, like Dr. Clay Sherrod.
Meade 7" LX200GPS Maksutov Hots:
- Killer optics
- Cool computer with excellent pointing accuracy and tracking
- So good on planets, it might embarrass some of your APO-loving friends
- Surprising results on deep sky objects
- Mirror lock and little mirror shift
- Zero image shift microfocuser
Meade 7" LX200 Maksutov Nots:
- Long cool-down time on drastic temperature changes
- Narrow field of view
- Motors are somewhat noisy, but you can turn them down
You can pick up a 7” LX200GPS on the used market for around $1300 - $2000 depending on condition and the included accessories.
|Optical Diameter:||7.0" (178mm)|
|Focal Length:||105.1" (2670mm)|
|Maximun Useful Magnification:||550x|
|Resolving Power (arc seconds):||0.64|
|Optical Coatings:|| MgF2 coatings on the correcting lens and standard aluminum coatings on the primary and secondary mirrors
(Ultra-High Transmission Coatings, available optionally for model #0715-50-31)
|Optical Tube Dimensions:||9.1 x 20.5" (23.1 x 52.1 cm) WxL|
|Mount Type:||Heavy duty fork type, double tine|
|Eyepiece Barrel Diameter:||1.25"|
|Tripod:||Adjustable field tripod (30-44")|
|Motor:||185 Speed micropressor controlled, 12V DC servo motor|
|PC Compatible:||Windows (compatible with Mac only through purchase of third-party software)|
|Power Source:|| 8 1.5-Volt "C" batteries (user supplied) = 20 hours
Optional 25' cigarette lighter plug (#607)
Optional 25' 115V AC adapter (#547)