Meade ETX-125EC Appendix a Advanced Electronic Controller Functions, Tracking Motor Speeds

Step 2. Step 4.

Step 3. Step 5.

Step 2. Step 4.

Step 3. Step 5.

Step 3. Step 4.

Step 5. Step 6. Step 8.

Appendix A: ADVANCED ELECTRONIC CONTROLLER FUNCTIONS

Tracking Motor Speeds

In the polar mode the Electronic Controller normally tracks objects at the sidereal rate (see SIDEREAL RATE, page 13). 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. 3) 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:

1.Press and hold the MODE key (5, Fig. 3) 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. 3) 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 IN key (7, Fig. 3) 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 sidereal rate, look through the eyepiece and continue to press the IN key until the object remains centered with little or no drifting in the eyepiece.

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 (6, Fig. 3) 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. If the object you're tracking is moving slower than the sidereal rate, look through the eyepiece and continue to press the OUT key until the object remains centered with little or no drifting in the eyepiece.

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. 3) to slew the telescope to the desired object. To change the slew speed, press the SPEED key.

Southern Hemisphere Polar:

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

3.Press the IN key (7, Fig. 3) 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 sidereal rate, look through the eyepiece and continue to press the IN key until the object remains centered with little or no drifting in the eyepiece.

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 (6, Fig. 3) 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. If the object you're tracking is moving slower than the sidereal rate, look through the eyepiece and continue to press the OUT key until the object remains centered with little or no drifting in the eyepiece.

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. 3) to slew the telescope to the desired object. To change the slew speed, press the SPEED key.

Changing Modes Using the Electronic Controller

The Electronic Controller is in the Alt/Az mode when activated, unless a mode screw has been removed. To use the Electronic Controller to change to Northern or Southern Hemisphere polar mode, or to use Alt/Az mode with one of the mode screws removed, use the following procedure:

1.Complete the POLAR ALIGNMENT PROCEDURE on page 16.

2.Complete steps 2 through 8 as described in TO MOVE THE TELESCOPE USING THE ELECTRONIC CONTROLLER, page 15, to initialize the Electronic Controller.

3.Press and hold the MODE key (5, Fig. 3) until lights 1 and 2 are on steady and lights 3 and 4 start blinking.

4.Press the SPEED key (3, Fig. 3) once. This changes the system to polar mode for the Earth’s Southern Hemisphere, with the motor drive set to operate at the sidereal rate.

5.Press the SPEED key a second time. This changes the system to polar mode for the Earth’s Northern hemisphere, with the motor drive set to operate at the sidereal rate.

6.Press the SPEED key a third time and the system returns to the Alt/Az mode. In the Alt/Az mode the motor drive does not activate when exiting from the Mode function.

7.Use the SPEED key as described in the above steps to cycle among these three modes (Alt/Az, Southern Hemisphere polar, or Northern Hemisphere-polar) until the desired mode is shown by the appropriate light configuration.

8.Press and hold the MODE key until just one light is on. This exits the Mode function. If you choose Northern or Southern Hemisphere polar mode, the motor drive starts operating at the sidereal rate.

9.Use the four Arrow keys (1, Fig. 3) to slew the telescope to the desired object. To change the slew speed, press the SPEED key.

- 26 -