The 1200GTO German Equatorial Mount with the GTOCP2 Control Box is not available to purchase. The information below is provided for present owners and those who are curious about its history. It is based on the original information with a few updates. If you are interested in some of the earlier or later models, check out this Brief History of the 1200 German Equatorial.
With the advent of the CCD camera, amateurs are exploring the skies to an ever increasing level of precision, easily exceeding the image quality of large observatories using film techniques decades ago. This new level puts a higher demand on the precision of the equatorial mounting. Many of the finest imagers today have been using our GTO mounts as a solid platform for a wide variety of instruments. The largest of these is our 1200GTO.
Since its introduction in 1998, the 1200GTO has gained a reputation for both tracking and pointing accuracy, essential to casual visual observation as well as advanced imaging. Quite a few 1200GTO and 900GTO mounts can be found at Mount Pinos in California, favorite observing site of many advanced photographers and imagers.
These mounts are truly a marvel of engineering - maximum strength and rigidity with minimum weight. Our CNC lathes and mills carve out the excess material in both axes of the 1200 and 900 German Equatorials while retaining a heavily ribbed structure for internal strength and rigidity. A unique dovetail was machined into the mating surfaces of the R.A. and Dec axes. This feature allows quick and easy assembly in the field without any tools.
The 1200 equatorial is equally at home in a permanent observatory or as a portable mounting for remote star parties thanks to the ease with which the two axes come apart. You CAN have it all. This is the perfect mount for a large refractor, Newtonian, Cassegrain or astrograph. Telescopes commonly used include Astro-Physics 155-206mm refractors, 12-14" Schmidt-Cassegrains and 10-16" Ritchey-Chretiens.
The 1200GTO mount is built from the ground up to be a precision imaging platform while still remaining totally user friendly. Consider these advantages and features:
Precise Mechanical Fabrication.Highly accurate mechanics.
|R.A. worm wheel||10.3" (26.2cm), 225 tooth aluminum|
|Declination worm wheel||7.2" (18.3cm), 225 tooth aluminum|
|R.A. shaft||3.35" (8.5cm) diameter|
|R.A. thrust bearings||9.5" (24.1cm) diameter|
|Dec. shaft||2.36" (6.0cm)diameter|
|Dec. thrust bearings||6.5" (16.5cm) diameter|
|Latitude range||20 to 68 degrees|
|Azimuth adjustment||Approximately 14 degrees|
|Right ascension||4-minute increments, pointer, engraved both|
|Declination||1 degree increments, engraved, pointer|
|Setting circles||Porter Slip Ring design, engraved, pointer|
Approximately 140 lb. (63.6kg) scope and accessories, depending on length. Will accommodate Astro-Physics and similar refractors up to 206mm f8, 16" Cassegrains and Ritchey-Chretiens
|Weight of equatorial head||91 lbs. (41.4kg), Dec axis is 30 lbs. (13.6kg), RA axis is 47 lbs. (21.4kg), counterweight shaft is 14 lbs. (6.4kg)|
Servo Motor Drive
The drive system uses a high-quality Swiss DC servo motor controlled by a microprocessor to an accuracy of 0.05 arc seconds per step. Tracking is very smooth, noticeably smoother than any stepper motor drive or inexpensive servo drive. The system can be accurately controlled over a speed range of 4800:1 which allows 0.25x sidereal for guiding to 1200x sidereal for 5 degree per second. The circuit draws only 0.4 amps when tracking the stars, 2 amps with both motors slewing and requires only 12 volts to operate. This servo drive will satisfy the requirements of the sophisticated, advanced astrophotographer, yet is easy for the casual, visual observer to use.
|The diagram shows several dimensions that are commonly requested. In addition, if the scope is horizontal and pointing west or south, the measurement from the top of the pier to the middle of the cradle plate is 11.25." Please note that these dimensions will vary somewhat depending on your latitude. We quote them for 42 degrees because that is the latitude of Astro-Physics and all of our equipment is set up that way. It is also a good average value.
Please refer to this PDF document of you are planning an observatory and need to know the variations in the horizontal distance from the center of the mount base plate to the center of the declination axis that are caused by different latitude settings. Note that the mount pictured has the polar forks introduced in 2004, however, as shown in the document, the dimensions are the same.
We have prepared some pertinent support documents relating to this mount and many of our other products on our Technical Support page. Please check there first to find the information that you need.
Upgrades and Spare Parts
Check out our Astro-Physics.com website to find accessories, replacement parts or learn about possible upgrades for your mount.
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This page was last modified: March 11, 2019
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