Starting the telescope

Cold Start

The telescope is occasionally unplugged for safety reasons, during thunderstorms or while electrical work is being done. To start up in this case:

• Make sure the telescope is zenith-pointing by checking the levels on the corner of the top box.
• Plug the two line cords into the orange electrical outlets. One is labeled 48" Rack, the other, 48" computer.

Warm Start

• Check that both stow pins are in the wall box. Make sure that the silver Drive Power switch is down (off).
• Turn on rack Main Power.
• Push silver Drive Power button up (on).
• Push the power button on the PC to get it to boot up, and turn on its monitor. The monitor should show text in a minute. Press space bar to start up PC-TCS.
• Check the PC-TCS monitor to see if the PANIC sign is flashing. If so, press F10, then F9, and then F10 again. The coordinate labels (RA & Dec) should turn from red to blue. A panic happens occasionally when the rack has been turned off.
• Go out into to the dome. Open the dome by pushing the remote switch on the wall out in the dome, twice if necessary. If necessary, use the hand paddle to rotate the dome to its stow position (north).
• Turn on the Guide TV Camera high voltage. (The power switch should have been left on.) Turn on the TV monitors and the cursor box (located in the control room). (You can skip all this if you don't plan to use the guide TV.)
• Once the dome is open (and preferably after waiting 5 minutes for dust to settle), open the mirror doors. Never open or close mirror doors unless the telescope is at Zenith! Mirror door switch is located on the rack near the main power switch.
• Open the dark slide on the camera, again after waiting until any dust from opening the shutter has had time to settle. (As of 1998 February, we are recommending that the dark slide be left open at all times. This will allow airflow to help keep the window clean.)
• Make sure the guide PC is booted up (see TCS manual). The infrared version, irtcs, works the same except that there are no buttons to change top box filters.
• On the Sun (flwo48), log in as irobs. Start up the telescope control system by typing irtcs & . The window you use will receive lots of text output, so you may want to use a new, out of the way, xterm window to start irtcs. After a while, the irtcs yellow window should appear. Put it where you want it. You can iconify the text window where you started irtcs. The telescope tracking and the dome tracking should be off when the TCS window pops up.
• Move the guide probe off axis with the On/Off Axis button.
• When ready to observe, toggle the telescope tracking, dome tracking, and CosDec on using the Tele Tasks Menu. Find a bright star. (The catalog IRstds.mct has elias and other IR standards; bright.mct has lots of very bright stars. Center the star image, and reset telescope coordinates via the Tele Tasks menu. Focus. You may have to use a very short integration time like 0.1 s if the star is bright. Saturation is above 20000 counts in the red and 10000 in the blue, but for most observing, it's a good idea to keep maximum counts in one pixel below 75% of saturation per coadd. (Coadding sums successive frames, and the saturation value increases accordingly. Also the counts above refer to counts above zero flux. For the 3.3, L, and M filters in 'single' mode, zero flux is around 20000 counts and saturation around 40000.)
• If you have trouble finding a star, try resetting the coordinates by levelling the telescope. Then reboot the telescope PC, hit space bar as usual. When the PC comes up, go to irtcs and select "Set PC Clock" in the Misc. menu. This should completely reinitialize all coordinates on the PC, and you should be able to find a star without difficulty. (Heh!)

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