The telescope has two sets of motion control: manual and motorized. The slew and setting motion is manual. The guide/fine motion is motorized. The telescope also has an RA tracking motor which can be set at sidereal, lunar, or other non-sidereal rates.
Manual slewing or setting of the telescope can be done in two ways. The more common way of moving the telescope is pushing it using the white rope covered ring (Figure 1). Alternatively, one may use the ship's wheels (Figure 2) on top of the telescope pier. Using the ship's wheels may be necessary when moving the telescope to certain areas of the sky (e.g. high north declinations) or when reversing the telescope.
When moving the telescope, one must first unclamp the telescope in both Right Ascension and Declination. The RA axis clamp is electric and controlled by any of three switches. Two of the RA clamps switches are mounted on the telescope ring (Figures 3 and 4) for easy access when moving the telescope from the floor. A third RA clamp switch is on top of the pier near the ship's wheels (Figure 2). To unclamp the RA axis, hold the switch towards the off position (or push the unclamp button when at the top of the pier) for a few seconds (the sound of the RA clamp motor changes indicating that the clamps are released). To engage the clamp simply push the swith towards the on position (or push the clamp button at the top of the pier) for a few seconds. Again the sound of the motor will change indicating that the clamp is engaged.
The Declination clamp is the ship's wheel on the telescope (at the right in Figure 1). To unclamp the declination axis, rotate the wheel counterclockwise at least half a turn. To clamp the declination axis, rotate the wheel clockwise until snug. It is not necessary to turn the declination clamp more than one full turn to unclamp, nor tighten it too snuggly when clamping (which could make it difficult to unclamp).
Once the RA and Dec clamps are released, one may carefully push the telescope to the desired position, using the Selsyn position indicators to set to the proper RA (or HA) and Dec. When moving the telescope always be cautious and aware of obstacles and the pointing limits of the telescope. Also be cautious not to strain cables or hit the declination tangent arm on the pier railing. One may have to move the floor up or down while positioning the telescope. Once the telescope is in position, clamp both the RA and Dec clamps.
If one wishes to use the ship's wheels to move the telescope, use the following procedure:
Small motions of the telescope (e.g. centering the object in the eyepiece field of view or guide motions) can be done with the guide paddle (Figure 7). There are four buttons to move the telescope in the cardinal directions (North, South, East, and West) and two toggle switches to enable the motion. The left toggle switch enables the RA axis motion, where up enables motion and down disables it. Similarly the righthand toggle switch is for the declination axis.
Tracking motion of the telescope is controlled by a motor whose power supply and speed adjustment are on the desk console (Figure 8). The main tracking motor power switch is on the right of the unit. Once the main power is turned on, tracking can be started by setting the tracking toggle switch to on (in the center of the unit). The lefthand toggle switch sets the rate of the telescope to either the sidereal or lunar tracking rates. Fine adjustment of the tracking rate can be accomplished by moving the rate toggle switch either left to decrease the rate or right to increase it. The LCD screen displays the current tracking rate in arcsec per seconds.
Figure 1: Back of the telescope