Avalon Linear Fast Reverse PHD Settings

[AndrewG]

I have recently upgraded my mount to the Avalon Linear Fast Reverse based on great advice on SGL and have noticed in a few threads that it was mentioned that PHD settings are available to help improve the tracking.

My question is therefore can anyone confirm what the recommended PHD settings are for the Avalon Linear?

Any help would be very appreciated.

Thanks

[Barry-Wilson]

Andy

I use PHD2 rather than PHD and eqascom pulse guiding and not ST4.  With pulse guiding, in eqmod I set RA & DEC Rate to 0.2x sidereal and set DEC backlash to zero.  I've found for my set up that 3 sec subs work well.  The aggressiveness and hysteresis settings can be reduced from the default.  Balance needs to be very good and you must not set east heavy; an accurate PA is a must as well as no flexibility in your set up.  This should give you a starting point to make your own adjustments to the settings.  As well as the graph trace within PHD, the pulse graph within eqmod also helps when adjusting settings and there is a good explanation on the eqmod website (in a downloadable pdf form too) and Chris Shillito's You Tube tutorials are excellent and I highly recommend them.

I see from your signature that you use a synguider: does this only use an ST4 connection?  Or can you use pulse guiding?  If I recall correctly from the Avalon Linear FR user manual, which I don't have to hand as I type, pulse guiding is recommended.

HTH

Barry

[AndrewG]

Andy

I use PHD2 rather than PHD and eqascom pulse guiding and not ST4.  With pulse guiding, in eqmod I set RA & DEC Rate to 0.2x sidereal and set DEC backlash to zero.  I've found for my set up that 3 sec subs work well.  The aggressiveness and hysteresis settings can be reduced from the default.  Balance needs to be very good and you must not set east heavy; an accurate PA is a must as well as no flexibility in your set up.  This should give you a starting point to make your own adjustments to the settings.  As well as the graph trace within PHD, the pulse graph within eqmod also helps when adjusting settings and there is a good explanation on the eqmod website (in a downloadable pdf form too) and Chris Shillito's You Tube tutorials are excellent and I highly recommend them.

I see from your signature that you use a synguider: does this only use an ST4 connection?  Or can you use pulse guiding?  If I recall correctly from the Avalon Linear FR user manual, which I don't have to hand as I type, pulse guiding is recommended.

HTH

Barry

Thanks Barry for the most useful tips.

I am using PHD2 with Pulse Guiding via Ascom using my new shiny Atik One c/w OAG and Atik GP; sorry haven't had chance to update my signature yet but will do it this weekend  . 

The Synguider is in its box and will probably end up on Ebay .

Will try the settings you confirm, I have already read the EQmod PDF but will watch some Utube tutorials as you suggest.

I do have a question regarding what makes the mount east heavy?   I have balanced the setup in Dec / RA by loosening the Avalon mount levers and thought that would be ok as I have just got the standard Tak OTA with finder and the camera mounted symmetrically, see the attached pick below.

Look forward to your comments.

Thanks again Andy.

[Barry-Wilson]

Andy - on traditional worm and gear mounts to ensure gear faces are engaged rather than minutely oscillating between meshed gear teeth, a common technique is to very slightly unbalance the mount (after balancing) by moving the counterweight along its shaft.  This is not needed with the belt drive Linear FR.

I've just upgraded to the latest PHD2 and am experimenting with the aggressiveness and hysteresis settings for DEC.  In the previous versions I had RA aggressiveness at 90% and hysteresis at 5.  Not sure yet what settings I'll have in the latest version.

I've a day-off work today and just been re-routing my cabling to reduce any residual drag.

That Tak FSQ looks at home on your set up . . . clear skies!

Barry

[Colincooper]

Hi Barry,

I was just reading this thread and see that you have pretty much the same setup as me...

a quick question if you don't mind?

how do you connect your Avalon to SGP?  do you use EQmod?  I don't want to unless I really have to.

many thanks

Colin

[Barry-Wilson]

Hi Collin

Yes I connect direct to the mount and use Eqmod, pulse guiding.  It's very easy to use and Chris Shillito has posted very helpful You Tube tutorials, http://www.youtube.com/user/chrisshillito.

Barry