how to create a PEC graph ?

[Vox45]

Hello all,

I want to sell my Sirius (HEQ5) mount but I've been asked if I could provide a "PE" graph. I have no idea how to do this. I know that ASCOM/EQMOD have some tools but I am not sure were to start and if there are other tools out there that could simply and efficiently create a graph that would mean something to potential buyers.

I know that some shops provide the service of tuning your mount and gives you a periodic error graphs ... I do not know what software they use to do that though.

I've hear of PEMPRO and K3CCDTools but they looked like very old tools.

Any ideas ?

[vlaiv]

This should be rather simple but a bit time consuming activity. You'll need something like hour or two of your time under stars.

Procedure would be the same as preparing PEC curve - disable any PEC if you have it, fire up PHD2 and do calibration but disable guide output in PHD2. Make sure guide logging is enabled in PHD2 and run "guide" session for about hour or so (HEQ5 has worm period of 638s if I remember correctly - and you want at least couple of cycles to get good PE curve). Once you are done, you can load PHD2 guide log in software called Pecprep - part of EQMOD project. It is used for analysis of PE data and generation of PEC curves.

Simple screen shot of PE curve in PEC prep is all you need. In fact - maybe just PHD2 log of this session is all that potential buyers will need - they can use either PECPrep or some other software to analyze it.

[Vox45]

Great ! Thank you for your answer

Now I just need to wait until the sky clears  

[Ken82]

Yea very simple as Vlad has explained. Start up phd2 and go to guide assistant which will make phd  stop tracking and just record the periodic error. 
 

then you just load it into PEC prep ensuring to input the correct mount details etc.