Astro-Physics 900GTO German Equatorial Mount
The Astro-Physics 900GTO is an excellent choice for 10 to 12.5 inch RCOS Ritchey-Chretiens.
RCOS is an authorized Astro-Physics dealer.
Modern CNC machining methods inspired Astro-Physics to carve out the excess material in both axes of the 900 and 1200 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. These mounts are truly a marvel of engineering - maximum strength and rigidity with minimum weight.
Features
- All machined mounting made from aluminum barstock and stainless steel. All fasteners are stainless steel.
- Motors and all electronic components are enclosed.
- Ball bearing races.
- Removable 1.875" stainless steel counterweight shaft.
- Polar and declination axes come apart quickly without tools for light-weight, easy handling and ease of transport.
- Fine altitude and azimuth adjustments for quickly and accurately zeroing in on the pole in the field.
- Engraved setting circles are Porter Slip Ring Design.
- Electronic components rated for industrial and automotive applications.
- Base fits into 8" outside diameter pier with 0.125" wall thickness.
Servo Motor Drive
The drive system uses a high-quality zero-cogging 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 motor. 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 slewing. The circuit draws only 0.4 amps when tracking the stars, 2 amps with both motors slewing and requires only 12 volts to operate. The servo drive will satisfy the requirements of the sophisticated, advanced astrophotographer, yet is easy for the casual, visual observer to use.
DigitalSkyVoice™ Software
DigitalSky Voice is a terrific observing companion offering lots of observing ideas and information. If you plan to use an IBM-compatible personal computer to control your telescope, you will have lots of fun with this program. The software is included with the mount.
| 900GTO Specifications | |
| R.A. worm wheel | 7.2" (18.3cm), 225 tooth aluminum |
| Declination worm wheel | 6" (15.2cm), 225 tooth aluminum |
| Worm gears | Brass |
| R.A. thrust surface | 7.0" (17.8cm) diameter |
| Declination thrust surface | 6.0" (15.2cm) diameter |
| R.A. shaft | 2.2" (5.6cm) diameter |
| Declination shaft | 1.75" (4.4cm) diameter |
| Latitude range | 20 to 68 degrees (0 to 20 degrees with latitude wedge Azimuth adjustment) |
| Azimuth adjustment | Approximately 14 degrees |
| Setting circles | Porter Slip Ring design, engraved |
| Right ascension | 4 minute increments, pointer, engraved both Northern/Southern |
| Declination | 1 degree increments, pointer |
| Capacity | 70 lbs. (31.8kg) depending on size |
| Weight of equatorial head | 50 lbs (22.2kg), Declination axis is 15 lbs. (6.8kg) right ascension axis is 25 lbs.(11.4kg), counterweight shaft is 10 lbs. (4.6kg) |
| Software | DigitalSky Voice™ |
Recommended Options
- Astro-Physics portable pier - 8" diameter, heights 24", 32", 42", 48", 54", 62"
- Astro-Physics 10 lb stainless steel counterweight
- Astro-Physics 18 lb stainless steel counterweight
- Mounting plates