ASTRO-PHYSICS 400GTO Assembly Instructions Manual - Page 11

Browse online or download pdf Assembly Instructions Manual for Telescope ASTRO-PHYSICS 400GTO. ASTRO-PHYSICS 400GTO 13 pages. German equatorial with servo motor drive

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them together. Plastic adhesive cable mounts, available from electronic supply stores, are an alternative choice. We prefer

to use ties since we cannot bear to attach adhesive cable mounts to our telescopes or mounts.

If we use tie wraps to secure several cables together and plan to use that same setup in our next observing session, we

keep the ties in place when we disassemble our equipment. The setup for the next session is much quicker.

GTO Keypad Controller Operation

Please refer to the manual for the GTO Keypad Controller for complete instructions.

MOUNT MAINTENANCE AND ALIGNMENT:

Under normal operating conditions, no maintenance is required. Your 400GTO is a precision instrument with very accurate

worm and wheel adjustments. Please be careful if you place the mount on a flat surface, i.e. the ground or trunk of your car.

This is true of any fine instrument. We suggest that you transport and store the mount in a case or in a well padded box.

TROUBLESHOOTING – additional tips are in the Keypad instruction

The LED on the GTO Control Box changes from red to yellow and the motors stop.

The motors are overloaded, probably due to an unbalanced load on your mount.

Rebalance your telescope, then press one of the N-S-E-W buttons to reset the keypad. Re-enter the last object on your

keypad and the scope will slew to the correct position. Even though your motors had stopped, the logic in the control box

retained the scope position in memory. As long as you didn't change the pointing position of the scope, you are still

calibrated.

If the scope was moved during re-balancing, simply enter a nearby bright star on the hand controller, press GOTO and allow

the mount to finish slewing. You can then move the scope manually or with the N-S-E-W buttons to center the star in the

eyepiece, and press the #9 RECAL button. This will recalibrate the mount.

Additional explanation: The GTO drive circuit includes logic for overload protection to prevent burning out the expensive

servo motors in case of severe overload on the two axes. The primary cause is an unbalanced load in R.A. If the extra load

opposes the motor rotation, the motor must work harder to track at the sidereal rate and the current will rise to high levels. If

the current exceeds the trip point for more than a minute, the logic will shut the motor off and tracking stops. It typically

takes about 4 lb. of unbalance to trip the overload, but a very heavy load of scopes, accessories and counterweights on the

mount can decrease this unbalance threshold.

The power light goes out and the motors stop.

The voltage of your battery has probably gone below 10 volts.

If any problems occur, please don't hesitate to contact Astro-Physics for assistance.