User's Guide to the Tauchmann 22-inch Telescope

Table of Contents

Telescope Pointing

Right Ascension Axis | Declination Axis | Pointing Procedure | Reversing the Telescope | Park Position

Right Ascension Axis

The HA Setting Circle Light is a small red bulb above the HA Position Indicator and is turned on from the Telescope Control Box with the Circle Lights switch. The major tick marks on the Setting Circle indicate hours of HA. The minor tick marks are every two minutes of HA. The Position Indicator is simply a pointer to the current HA setting on the circle.

The RA Clamp is unclamped when the lever is parallel to the RA rotation axis and clamped when it is perpendicular to the RA Axis. The RA clamp is clamped as showns in Figure 1. The RA clamp can be difficult to reach for some HAs, so one will just have to carefullreach under the RA axis to release the clamp before moving the telescope manually using the RA Positioning Handle (Figure 2).

When the RA is clamped, the fine motion motor can be used to fine tune pointing of the telescope from the Telescope Control Box RA Slow Motion switch. The fine motion motor is connected to the RA Tangent Arm lead screw (Figure 3). This lead screw has limited length and great care needs to be taken to be sure one doesn't run the tangent arm off the end of the lead screw or jam it into the fixed end. If the tangent arm is close to either end of the screw, use the slow motion switch to move it back to the center of its travel and use the RA Positioning Handle to reposition the telescope on the target. At that point, one can again use the slow motion switch to center the target in the eyepiece. Note that the RA slow motion struggles to drive west, so it may be necessary to pull on the RA positioning handle while driving the RA slow motion.

There are limit switches on the RA axis to prevent pointing the telescope too far east or west. When a limit switch is triggered, the telescope RA drive will stop. Do not force the telescope to move past either the east or west limit as that will cause damage to the telescope.

Figure 1: RA/HA Axis Setting Circle, Clamp, and Fine Motion Control Motor	Figure 2: RA Axis Positioning Handle
Figure 3: RA Tangent Arm Lead Screw

Declination Axis

The Dec Setting Circle Light is a small red bulb above the Dec Position Indicator and turned on from the Telescope Control Box with the Circle Lights switch. The major tick marks on the Dec Setting Circle are every 10 degrees, with the minor tick marks every 1 degree. The Dec position indicator is a Vernier Scale. To set the Dec one aligns the desired Degrees to the main (central) tick mark on the position indicator. Then to get to sub-degree positioning, shift the telescope slightly to align the minor tick mark to the desired tenth of a degree.

The Dec Clamp is unclamped when the lever is parallel to the Dec axis and clamped when perpendicular to the axis. Figure 1 shows the Dec clamp in the clamped position. One must unclamp the Dec axis before using the Dec Positioning Handle (Figure 6) to move the telescope.

When the Dec is clamped, the fine motion motor can be used to fine tune pointing of the telescope from the Telescope Control Box Dec Slow Motion Switch. The fine motion motor is connected to the Dec Tangent Arm(Figure 4) via a lead screw (Figure 7). The lead screw has limited length and great care needs to be taken to be sure one doesn't run the tangent arm off the end of the lead screw or jam it into the fixed end. If the tangent arem is close to either end of the screw, use the slow motion switch to move it back to the center of travel and use the Dec Positioning Handle to reposition the telescope on the target. At that point, one can again use the slow motion switch to center the target in the eyepiece.

Figure 4: Dec Axis Setting Circle and Clamp	Figure 5: Dec Tangent Arm and Fine Motion Control Motor
Figure 6: Dec Axis Positioning Handle	Figure 7: Dec Tangent Arm Lead Screw

Pointing Procedure

1. Unclamp RA and Dec.
2. Use the RA Positioning Handle to align the telescope with the desired HA.
3. Clamp RA.
4. Use the Dec Positioning Handle to align the telescope with the desired Dec.
5. Clamp Dec.
6. Rotate the dome so it is aligned with the telescope.
7. Use the Telrad to center the object, unclamping RA and Dec and using the Positioning Handles, and reclamping RA and Dec, as needed.
8. After the object is centered in the Telrad, one can move to using the Finder Scope and the RA and Dec Slow Motion switches on the Telescope Control Box to center the object in the Finder Scope.
9. Select the Wide Field Eyepiece.
10. With luck the object will be in the Wide Field Eyepiece field of view and one can use the Slow Motion switches to center the object in the eyepiece. If not, one may have to hunt for the target, in which case take care to not run the RA or Dec Tangent Arm too far.
11. Once centered in the Wide Field Eyepiece, focus the telescope using the Focus switch on the Telescope Control Box.
12. If desired, one can switch to the 1.25" eyepiece for a more magnified view.
13. Once centered in the eyepiece, adjust focus by moving the 1.25" eyepiece in its drawtube.
14. One can adjust the tracking rate if necessary by adjusting the Oscillator dial.
15. Adjust dome rotation as needed to keep the dome aligned with the telescope.
16. Enjoy observing!

Reversing the Telescope

Park Position

1. Turn off Oscillator and ALTEC amplifier.
2. Disengage RA and Dec clamps.
3. Position telescope at HA = 00:00 and Dec at its southern physical stop.
4. Clamp RA and Dec clamps.