Set Up

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Physical Set Up:

  1. Orient tripod / wedge to true north. Set tripod legs at lowest setting. Bolt wedge snug to tripod. Use compass to sight along altitude bolt from 10 ft south looking north. Compass should be readable wrt magnetic deviation for area (18 degrees E for Oregon). Standing too close allows magnetic properties of the tripod to mess things up.
  2. Level the tripod. Built in bubble level is fine for my scope. Be careful to not over tighten the knobs for the telescoping legs. Also, keep tripod as short as possible for stability.
  3. Mount telescope onto wedge. First check all wedge / tripod bolts: is it stable, will it hold? Lift scope with axis locks unlocked. (Don't break back.) Allow OTA to flop onto shoulder while carrying to and fitting on wedge. Tighten all three bolts that hold scope to wedge! (I've actually forgotten this twice!)
  4. Attach goodies. (accessories and cables). Make sure power switch is off, and attach power cable last. If this is a PC driven run, then attach PC cables now (no hot plugging later). Reseat all cables a couple of times to keep contacts fresh.  Don't forget the DEC cable inside the west fork (if left alone for a long time it can become intermittent according to some MAPUG'ers).
  5. Balance. This is crucial. In summery, I balance in 3D (2D DEC plus RA). To get more precision in balancing DEC, use the RA bearings for the out of balance telltale since they have less stiction. (See here for balance equipment description)
    1. remove main dust cover from corrector plate (its very heavy). If the sun is still out, watch out!
    2. set and lock DEC to +90° and move RA such that fork is horizontal and unlocked then balance in RA with Velcro ankle weight on east (non-motorized) fork. A small amount out of balance towards the East is OK to pre-load sidereal tracking.
    3. leave DEC locked at +90° and rotate in RA till the forks are vertical. Adjust 2D weight for least weight farthest out on spindle using unlocked RA for telltale.
    4. set and lock DEC to 0° while leaving RA alone (unlocked, forks vertical). OTA should be horizontal E/W now. Slide spindle along OTA until balanced about RA in this configuration.
    5. unlock RA and DEC and place OTA in many positions checking for balance. It should be perfect.
  6. Align spotting scope(s). Use some far away object or early bright star or planet.
  7. Power up and initialize.

Polar Alignment:

To reduce DEC drive reversals consider leaving a slight polar misalignment in place so that the target always drifts the same direction. So far, I have never done this, but it could be good for a long guided exposures.

  1. Get scope setting circles near 0 RA and +90° DEC by hand and / or keypad.
  2. Make sure RA and DEC locks are tight.
  3. Make final DEC adjustment towards south to take up gear lash.
  4. Trigger polar align sequence with keypad and follow displayed instructions. (At end scope will be pointing to non-Polaris alignment star).
  5. GOTO a star a "long way away" from Polaris in RA and DEC, center with keypad and sync. If this star has a Meade star number, remember it (it's the easiest way to go back).
  6. GOTO star 19 (Polaris) and adjust to center using wedge. (Don't bother with going only halfway, since star is 90° away from Polaris, there should be no coupling).
  7. repeat 5 and  6 several times.

I think that while the above procedure seems to work pretty well, there are still errors built in. The following list is in order of import:

The good news is that drift align will be insensitive to all these effects.

Drift Align:

When really precise alignment is required (improved pointing, longer unguided exposures, less field rotation in longer guide scope guided exposures) it is claimed that "drift alignment" can't be beat. And it can be done on any equatorial mounted telescope. (I do not yet know how far out LX200 Polar Align leaves things). The most serious drift align notes can be found here.

  1. Set-up / definitions / expectations:
  2. Center up a star near the meridian / celestial equator and let the scope track.
  3. Center up a star on the celestial equator within 15°-20° of the horizon and let the scope track.
  4. If step 3 caused major change (several degrees, how many eyepiece fields?), then repeat steps 2.  There is some coupling of the two axis since the horizon star is not actually on the horizon.

Daytime Observing Set Up:

Alignment

At power up the LX200 sets RA equal to the Sidereal time (the meridian). Then the scope hunts west to find the worm index. RA is adjusted during the hunt. Therefore, the LX200 will a be pointing further west by up to 8 minutes (the worm period) but it will keep track of where it is.