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What could I be doing wrong with phd

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#1 Suresh

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Posted 21 February 2020 - 01:35 AM

Hello friends ,
It’s been a long time since I’ve posted here . Ive been into AP for a long time . Recently I started using Samyang 135 mm lens with qhy183 M( 3asp) and for guiding I use hour lodestar with guidescope( 9 asp ) . Mount is AP Mach 1 which has a PE of 1 arc second . I guide with phd (native settings of aggression 100/ hysterisis 10 . I’m polar aligned with 1 arc min . I calibrate and then run guiding assistant for 5 minutes and accept settings . Star is chosen via auto select . My balance is slightly east heavy ( not required as it’s spring loaded ). I usually start imaging an hour before crossing meridian using the flip .my problem is I get pin point stars till it just crosses meridian , but as the stars set towards the west I’m noticing an east west drift . I’ve also tried without guding and the drift is not seen . You may ask me why am I guiding in the first place . My doubt is if phd is taking control or overdoing it . I know I must send the logs , but just looking for advice from seniors. My seeing is about 1.5-2 arc seconds .is the difference in asp between the guiding scope of 3:1 causing this ? Thanks
Thanks

Edited by Suresh, 21 February 2020 - 02:21 AM.


#2 jerahian

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Posted 21 February 2020 - 01:55 AM

 Side-to-side flexure with your guide scope?



#3 Suresh

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Posted 21 February 2020 - 02:11 AM

Side-to-side flexure with your guide scope?

Nearly impossible as the whole setup is rigid

#4 ButterFly

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Posted 21 February 2020 - 04:12 AM

What are the minimum motion settings?  It's sounding like oscillations as you chase seeing.



#5 Suresh

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Posted 21 February 2020 - 04:50 AM

It’s 0.10 but as per the guiding assistant on a day to day basis so some variation will be there

#6 Madratter

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Posted 21 February 2020 - 08:43 AM

You may not believe flexure, but it is differential flexure, almost for sure. Blink through a series of subs where you are seeing the problem and report what you are seeing.




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