Re: RA rate drift (revisited)
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Hi Greg,
Thanks for the notes.??
When using the PHD2 drift tool, it is only the DEC drift you want to null out (not RA drift), as that tool says in its instructions.
[ repeat these 2 steps...
When you are pointing first near meridian and celestial equator, only adjust the AZ knobs.
When pointing next, as far East or West as possible, then again look only at DEC drift, and null out with the AZ knob.??
]
Repeat...[...] til you are satisfied.
You really don't need to bother about the PEC... you can ignore errors in that for the drift alignment (by PHD2 anyway).
Best, Michael?
On Nov 5, 2017 1:03 PM, " beneckerus@... [Losmandy_users]" < Losmandy_users@...> wrote:
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This subject is a current topic on the Astro-Physics group (#59424) and the subject of using PHD2 was discussed.? PHD2 displays both the DEC and RA drift in the Drift Alignment tool.? So instead of letting PHD2 slew the scope to the East for the altitude adjustment, slew it manually to the zenith.? Turn on your mount's PEC to minimize RA motion.? Run the drift session for a full worm cycle to cancel out the effects of the remaining PE.? Adjust the altitude to minimize the RA drift.? There is no? point in doing the Eastern altitude adjustment first as this will always change for the minimum RA drift adjustment.
I found it interesting to think about this at the limit of doing polar alignment at the equator, where the intersection of the celestial equator and the meridian is also the zenith.? Using this method there you would not move the scope from the zenith for either adjustment
Greg
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Michael Herman