Meade LXD 75 instruction manual Tracking Rates

Fig. 52a: Indicator Light Key for changing tracking rates in the Northern Hemisphere Polar mode.

Fig. 52b: Indicator Light Key for changing tracking rates in the Southern Hemisphere Polar mode.

7.When the test is complete, light 1 remains on; lights 2, 3, and 4 turn off.

8.Use the four Arrow keys (1, Fig. 49) to slew the telescope to the desired object. To change the slew speed, press SPEED.

9.Fine-adjust the position of the object with the Electronic Controller Arrow keys so that it is centered in the viewfinder. The object is now ready to be viewed through the telescope’s eyepiece.

Tracking Rates

In polar mode the Electronic Controller normally tracks objects at the sidereal rate (see TRACKING OBJECTS, page 17). For 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. 49) 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:

Use the following procedure to change tracking rates when using the Northern Hemisphere polar mode. Refer to Fig. 52a.

1.Press and hold MODE (5, Fig. 49) 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 cho- sen).

2.Press SPEED (3, Fig. 49) until lights 1, 2, and 3 are on steady with light 4 blink- ing. The telescope is now in the Northern Hemisphere polar mode.

3.Press IN (7, Fig. 49) and light 4 comes on steady. The tracking rate is now 0.5% faster than sidereal. If the object you're tracking is moving faster than the sidere- al rate, look through the eyepiece and press IN. Each time you press IN, the track- ing rate increases by 0.5%. Note that when the Mode function is active, the tracking motor stops. To restart the tracking motor, press MODE again. Experiment with this function to get the right speed: Press IN to set the tracking rate. Then press MODE and look through the eyepiece. Continue pressing IN and MODE until the object remains centered with little or no drifting in the eyepiece.

Note: The tracking rate can be increased by up to 65%.

4.To use a rate slower than sidereal, press OUT (6, Fig. 49) until light 4 blinks again (sidereal rate). Press OUT again and light 4 goes out, signifying a tracking rate 0.5% slower than sidereal. Note that when the Mode function is active, the tracking motor stops. To restart the tracking motor, press MODE again. Experiment with this function to get the right speed: Press OUT to set the track- ing rate. Then press MODE and look through the eyepiece. Continue pressing OUT and MODE until the object remains centered with little or no drifting in the eyepiece.

Note: The tracking rate can be decreased by up to 65%.

5.Press and hold MODE 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. 49) to slew the telescope to the desired object. To change the slew speed, press SPEED.

Use the following procedure to change tracking rates when using the Southern Hemisphere polar mode. Refer to Fig. 52b.

1.Press and hold MODE (5, Fig. 49) 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 SPEED (3, Fig. 49) until lights 1 and 2 are on steady, light 3 is off, and Light 4 is blinking.

3.Press IN (7, Fig. 49) and light 4 comes on steady. The tracking rate is now 0.5% faster than sidereal. Note that when the Mode function is active, the tracking motor stops. To restart the tracking motor, press MODE again. Experiment with this function to get the right speed: Press IN to set the tracking rate. Then press MODE and look through the eyepiece. Continue pressing IN and MODE until the object remains centered with little or no drifting in the eyepiece.