Meade ETX-90EC Appendix Atracking Motor Speed, Northern Hemisphere Polar Indicator Light Key

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	Appendix A:TRACKING MOTOR SPEED

APPENDIX In the polar mode the Electronic Controller normally tracks objects at the sidereal rate (see Sidereal Rate, page 10). For A most observing sessions (once the telescope has been polar aligned and the tracking motor activated), there is little need to

change this speed.

For objects, like the Moon or a comet, that move at slightly different rates, the Electronic Controller arrow keys (1, Fig. 6) are sufficient to move the telescope slightly as the object very slowly moves off-center through the eyepiece field.

To change the tracking rate, for extended observations of an object not moving at the sidereal rate, follow the procedure for the appropriate hemisphere:

Northern Hemisphere Polar:

Indicator Light Key

The procedures in this manual identify the status of the four indicator lights in a box to the left of the appropriate step. They are depicted as on, blinking or off, depending on the mode at that point.

Southern Hemisphere Polar:

Light No.	Light Status
Light 1		On
Light 2		Blinking
Light 3		Off
Light 4

1.Press and hold the MODE key (5, Fig. 6) until the Mode function is active (i.e., lights 1 and 2 are on steady; lights 3 and 4 signify whatever tracking mode was last chosen).

2. Press the SPEED key (3, Fig. 6) until lights 1, 2, and 3 are on steady with light 4 blinking. The telescope is now in the Northern Hemisphere Polar mode.

3. Press the INkey and light 4 comes on steady. The tracking rate is now 0.5% faster than sidereal. Continue pressing IN until the desired speed is reached.

NOTE:The tracking rate can be increased by up to 65% (127 presses of the IN key).

4. To use a rate slower than sidereal, press the OUT key until light 4 blinks again (sidereal rate). Press the OUT key again and light 4 goes out, signifying a tracking rate 0.5% slower than sidereal. Pressing an additional 3 to 4 times will slow the tracking rate to the lunar rate.

NOTE:The tracking rate can be decreased by up to 65% (127 presses of the OUT key).

5. Press and hold the MODE key until only a single light is on. This exits the Mode function. If Northern or Southern Hemisphere polar mode was chosen, the motor drive starts operating at the sidereal rate.

6.Use the four arrow keys (1, Fig. 6) to slew the telescope to the desired object. To change the slew speed, press the SPEED key.

1.Press and hold the MODE key (5, Fig. 6) until the Mode function is active (i.e., lights 1 and 2 are on steady; lights 3 and 4 signify the tracking mode last chosen).

2.Press the SPEED key (3, Fig. 6) until lights 1 and 2 are on steady, light 3 is off, and Light 4 is

blinking.

3. Press the INkey and light 4 comes on steady. The tracking rate is now 0.5% faster than sidereal. Continue pressing INuntil the desired speed is reached.

NOTE:The tracking rate can be increased by up to 65% (127 presses of the IN key).

4.To use a rate slower than sidereal, press the OUT key until light 4 blinks again (sidereal rate). Press

the OUT key again and light 4 goes out, signifying a tracking rate 0.5% slower than sidereal. Pressing an additional 3 to 4 times will slow the tracking rate to the lunar rate.

NOTE:The tracking rate can be decreased by up to 65% (127 presses of the OUT key).

5. Press and hold the MODE key until only a single light is on. This exits the Mode function. If Northern or Southern Hemisphere polar mode was chosen, the motor drive starts operating at the sidereal rate.

6.Use the four arrow keys (1, Fig. 6) to slew the telescope to the desired object. To change the slew speed, press the SPEEDkey.