PE improvement after belt mode... How can I tell ?

[Vox45]

After doing a Rowan belt mode modification for myself on my Sirius mount, I helped a friend do the same on his mount (HEQ5)

Here is a video I took at the time comparing the noise between the 2 modes (gear vs belt)

This time I was better prepared and it took less than 45 minutes to do the mode Thank god for the pinion extractor btw!

I also took the time to do a before/after comparison using EQMOD to record the PE of the mount before the mode and after the mode. Once I got it done, I loaded the files in PECprep and was surprised to see that the error peak to peak seems to be bigger ....

Now, I may be wrong as I am not really sure on how to analyse this.. Anyone could look at this and let me know if there is an issue there ?

 

PE before the mode

 

PE after the mode

 

 

[libraryman]

The  statistics imply that you were guiding whilst gathering the pe data ( to my thinking at least) please correct me if I'm wrong.

try using the PhD log ( unguided) and load that into PECprep...

 

Ray

[Vox45]

33 minutes ago, libraryman said:

The  statistics imply that you were guiding whilst gathering the pe data ( to my thinking at least) please correct me if I'm wrong.

try using the PhD log ( unguided) and load that into PECprep...

 

Ray

No I wasn't guiding. The way I gathered the log is as follow:

(1) I pointed the scope to a star near the meridian at ~40°

(2) I launched the PEC recording in EQMOD and let it run until auto pec kicked in

(3) I stopped PEC and saved the file to disk

I did the mode and repeated the steps above.

Hopefully this was the correct way to do it as I won't get a third chance

[theastrodragon]

I'm not familiar with EQMOD, but I see an HEQ5 reporting a PEC of +/- 0.04 arcsec suspiciously amazing.

Heck, it would be pretty amazing if guided, let alone unguided. It does make me suspect something is amiss with the reported errors.

[Vox45]

17 hours ago, theastrodragon said:

I'm not familiar with EQMOD, but I see an HEQ5 reporting a PEC of +/- 0.04 arcsec suspiciously amazing.

Heck, it would be pretty amazing if guided, let alone unguided. It does make me suspect something is amiss with the reported errors.

Arf ... you may be right about my method, it might not have been the proper way of recording the difference.

No answer from the EQMOD Yahoo group either. I'll need to dig into this and read the documentation

[Xplode]

To get correct periodic error in arcseconds you need to load a logfile that allows you to set focal length and pixels size