Hello:

I have a 10" Meade LX200GPS Scope. I assume that one complete worm cycle for this scope is 24 minutes which consist 3x8 worm phases. Don't know if I'm wording it correctly. Is it better to acquire a single 24 minute cycle and then subsequent single cycles to refine the data? Or should I acquire multiple (3 or more) cycles and then subsequent multiple cycles to refine the data? Is PEMPro any more accurate in either case.

Also, I've been creating a new refined curve every few observing sessions and I noticed that the curve taken with PEC on is progressively getting flatter each time. On my 14th refine, I've gotten it to read +0.7/-0.7 5th Order with a created curve to add to my 13th curve read Peak to Peak PE: 1.73 Arc-sec, RMS: 0.35 Arc-sec. This was achieved by acquiring single 24 minute complete cycles.

PemPro-2009-09-08-021918.ppc (+) PEC On 13th Refine Training 090809.ppc

Now on my 16th refine, my acquired refine data read +1.4/-1.2 5th Order with a created curve to add to my 15th curve Peak to Peak PE: 3.25 Arc-sec, RMS: 0.78 Arc-secs.

PemPro-2009-09-27-012457.ppc (+) PEC On 16th Refine Training 092609.ppc

This curve was achieved by acquiring 3 complete cycles 2x on the same night. Why did it not get better? Should I just stick with my previous best? Or did I just do something wrong this time?

Seems like I can only attach one file at a time.

PemPro-2009-09-08-021918.txt (97 KB, 7 downloads) Aquired refine data

Ralph,

You can only do so much improvement before the results don't get better. The residual PEC that you are seeing probably are caused by at least two things:

1) The Meade PEC Cell values are non-linear quantized values so one unit change in a PEC cell may make comparitively dramatic change in the curve you measure with PEC enabled.

2) There are tiny imperfections in the worm wheel teeth which are different between each worm cycle which can slightly influence the curves.

-Ray

Then I should load the curve that created the best result and call it a day instead of going forward to try and get back to my previous best result?

What about my first question? Should we acquire a single 24 minute cycle or multiple cycles when acquiring the data? Which will produce the best, and most consistent results?

Ralph,

quote:

Then I should load the curve that created the best result and call it a day instead of going forward to try and get back to my previous best result?

Yes, I would.

quote:

What about my first question? Should we acquire a single 24 minute cycle or multiple cycles when acquiring the data? Which will produce the best, and most consistent results?

I typically recommend two complete cycles (48 minutes).

-Ray