Hi to all, I used the Speed Compensation tuning item (+/- ppm) on the SynScan Pro App on my EQ6-R PRO Mount . I used it with a +1000 ppm and it seems to work well . I tried a larger value (+2500 ppm) and it seems not to work , a larger value gave erratic results . I am wondering if there are limits on the parameter itself and I am quite convinced there are some . I would like to get your feedbacks on this very specific topic. I will continue to experiment : +1999 ppm to check the limit on my next try .
The method is the following : I take a serie of photos (10 sec each with 6400 ISO) for at least 10 mn and I use astrometry plate solving in SIRIL to recover the coordinate in J2000 in AD and DEC. Then I can follow the evolution (PEC off for the moment) and I recover a quite nice sinusoid : the inchworm periodic error plus a slight linear decrease of AD that I correct with Speed Compensation unit . A AD curve (unit are equivalent to asec of angle in Y axis, I delete constant value) . You can see the decrease linear decrease by measuring the top of the sine.