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Old 14-05-2015, 10:34 PM
Garbz (Chris)
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Garbz is offline
 
Join Date: May 2012
Location: Brisbane
Posts: 644
Quote:
Originally Posted by alpal View Post
It depends on your particular system.
Indeed, but PE can be corrected for in other ways not just pulse guiding.

Also I don't buy that the correction is an issue when using a pulse guider as it's a series of commands sent to software. It may make an issue with ST-4 where the pulse is actually sent out to the mount, but I ask you the following: What's the difference between 20x1, and 100x0.2 ? It's just a software calculation and the resulting 20ms pulse gets sent to the mount in either case.

In any case I've tried both high mid and low settings and it hasn't made a difference.

Quote:
Originally Posted by Slawomir View Post
Could also be cord catching or perhaps movement under gravity somewhere in the system?
Yeah I've checked both of these and it's a recurring issue despite me having moved my scope all over the place in the past year. That spike in the graph above was the result while shooting pretty much straight up so very little impact with the cable. Also the magnitude of the spike would imply it's not a cable issue either. It knocked the star off considerably, the resulting picture didn't just have eggy stars it had sperm

Quote:
Originally Posted by LewisM View Post
What Allan saod. I set my guide rate at 0.75 or 1 and rarely get issues.

I once did have a dec spuke like yours (exactly at 3:30 each time, so exactly half a cycle). Mine was just too tifht backlash adjustment.
I've checked the period, there is none. Originally I thought the worm was catching on something, but if that were the case it would show up at either a regular interval or multiple thereof.
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