and Dec. Damper Knobs 14 R.A. and Dec. Clutch Knobs 14 Balancing Your Telescope 14 SERVO MOTOR DRIVE 16 GTO Control Box – Model GTOCP2 16 R.A. and Dec. Cable Connections 16 12V Connector 16 POWER Indicator Light 16 KEYPAD Connector 16 RS-232 Connectors 17 FOCUS Connector 17 RETICLE Connector 17 AUTOGUIDER Connector 17 +6V Connector 17 N and S Switch 17 Prevent the Cables from Tangling 18 1200 Motor Cables 18 Accessory Cables 18 Removing the GTO Control Box From 1200 Mount 18 GTO Keypad Controller Operation 18 3 MOUNT MAINTENANCE AND ALIGNMENT 19 TROUBLESHOOTING 19 INSTALLATION OF ENCODERS AND ENCODER HOUSINGS -1200 MOUNT 21 Fitting Declination Encoder Housing 21 Fitting Right Ascension Encoder Housing 22 Periodic Maintenance 22 4 ASTRO-PHYSICS 1200 GERMAN EQUATORIAL WITH GTO SERVO MOTOR DRIVE MODEL 1200GTO PARTS LIST – MODEL GTOCP2 1 Polar axis assembly (right ascension-R.A.) with Servo Box GTOCP2 1 Declination (Dec.) axis assembly 1 Pier top adapter with six (6) 5/16-18 x 5/8" button head screws with washers (these may be attached to your pier post if you ordered one) 1 Stainless counterweight shaft with washer stop and black plastic knob (knob has 5/16 thread) 1 Y cable – R.A. portion is 12.5” long and Dec portion is 37.5” long 1 D.C. power cord (cigarette lighter adapter on one end) - 8’ long 1 GTO Keypad controller with 15’ coiled cable 1 Keypad Protector (KEYPRO) 1 DigitalSky Voice. Software (CD-ROM) 1 Hex key set 2 8-32 thumbscrews (substitute these for 8-32 set screws that hold GTO Servo Control Box in place, if you wish) In order to fully assemble your mount, you will need the following items sold separately: mounting plate, 10” O.D. pier, counterweights, and portable rechargeable battery pack (or 110 to 12V DC converter). Several sizes and types are available for your selection. Many of these items will be discussed throughout these instructions. Several additional options are available: Longer counterweight shaft – 27” useable length, part # M12661 Santa Barbara Instrument Group CCD Imaging cameras and ST-4 Autoguider or STV - if you plan to pursue CCD imaging or astrophotography Pier accessory trays for 10” pier and support bars - handy to keep your eyepieces close at hand Polar axis telescope - threads into the base of the polar axis assembly. Many users find a polar axis telescope useful for zeroing in on the pole quickly, particularly with telescopes that are not orthogonal to the mount. Mounted encoders – Although you can use these with your mount, they are not necessary since the go-to functions of the mount are more accurate. The 4000 steps of the encoders, which read the position of the shaft are very coarse (324 arc seconds) while the encoder that is built into the servo motor itself is 0.05 arc seconds. FEATURES AND SPECIFICATIONS R.A. worm wheel: Dec worm wheel: Worm gear: R.A. shaft: R.A. thrust bearings: Dec shaft: Dec thrust bearings: Counterweight shaft: 10.3”, 225-tooth aluminum 7.2”, 225-tooth aluminum Brass 3.35” diameter 9.5” diameter 2.36” diameter 6.5” diameter 18” useable length, 1.875” diameter, stainless steel, removable Azimuth adjustment: Setting circles: Right ascension: Declination: Motors: Power Consumption: Power requirements: Weight of mount: Approximately 14 degrees Porter Slip Ring design, engraved 4-minute increments, pointer 1-degree increments, pointer Zero-cogging servo motors 0.4 amps at the sidereal rate 3 amps both motors slewing 12 VDC, range 11.5 to 15 total -91 lbs. Dec axis - 30 lbs. Latitude range: 20 to 68 degrees with or without polar scope or encoders attached (if you are R.A axis - 47 lbs. counterweight shaft -14 lbs. above 65° you will have to remove one pier top knob) 5 INTRODUCTION The 1200 German equatorial was designed to meet the needs of the advanced observer who requires a mount with maximum strength and rigidity and minimum weight. The excess material in both axes has been carved out 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 DC servo motor drive with GTO computer system, including the keypad controller with its digital display screen and DigitalSky Voice software offer extraordinary sophistication for today’s observer. Whether you enjoy visual astronomy exclusively or plan an aggressive astrophotography or CCD imaging program, this mount will allow you to maximize your night out under the stars. The advanced keypad features allow you to slew automatically to objects in a wide range of databases as well as any RA/Dec coordinate. A large selection of common names for stars and other objects makes your selection a snap. The rapid slew rate of 5 degrees per second (1200x) allows you to locate objects very quickly and accurately. You will be very pleased with the intuitive operation of this controller. There are no complicated sequences of keystrokes...