Anyone Using Permanent PEC Feature on AZ-EQ6 or EQ8?

[TimC]

Hi Everyone,

I am wondering if anyone has tried using the permanent periodic error correction feature on their AZ-EQ6 or EQ8 and if so how did you program the mount?

I have a new AZ-EQ6 (actually Orion Atlas Pro - U.S. version).  I like EQMOD and have used it on my old Atlas/EQ6 but recently discovered that EQMOD doesn't support permanent periodic error correction - only the software based PEC so you you have to remember to park the mount each time for it to retain the PEC curve and be in sync with the mount's worm position.  That never worked well for me with my old Atlas so was excited to try permanent PEC.  I'm just scratching my head on how to go about it.  I do have  a copy of Pempro and would like to be able to program my mount using that software but how does one control the mount with a PC while using the PPEC if EQMOD doesn't support it?

My Atlas Pro has a very regular/repeating PE curve (17 arc sec peak to peak according to Pempro) so should do well with PEC.

Thanks for any insights!

Tim

[TimC]

Well, I've asked this question in several forums so I can only  conclude that folks aren't using it so much :0.  Anyway, I'm intrigued by what EQMOD can do these days with Autopec and also just found that my QHY5L-ii works with Perecorder so looks like I have some good options to explore.  Just have to remember to park my mount!

[Fred_76]

The AZEQ6 manual says there is an index on the RA so that the mount knows where the worm is : no need to park the mount anymore to do the PEC. This is why they call it PPEC, the first P stands for Permanent.

However, to date, EQMod doesn't recover this RA index information. So the PPEC is useless with EQMod, until the developpers find a way to get the reading.

Fred

[chrisshillito]

As far as I know skywatcher don't provide any access to the mounts (or maybe handcontroller?) PPEC and so there is no way EQMOD can directly program it. EQMOD's PEC (which is also permanent as it is held on you PC's hard disk!) was designed for the EQ6Pro/HEQ5 mounts but will work with the AZ-EQ6GT. I would appear that EQMOD PEC does not play nicely with the  EQ8 however due to changes skywatcher have introduced for that mount that appear to scale some of the underlying mount parameters differently.

With EQMOD PEC it is a pre-requisite that the mounts encoders are re-synched to the same state as they were when the PEC was originally recorded. Parking/Unparking is one way to ensure this, as is using the EQMOD resynch encoders mechanism (provided you have a way to accurately position the RA axis to a known position). The auto home function of the newer mounts another method. So, if you are using an AZ-EQ6GT and parking/unparking is just too much of a hassle you could instead use the handcontroller to auto-home the mount prior to recording PEC and prior to connecting up EQMOD. If switching over to the handcontroller as part of setup is a pain then I believe there is a small standalone application available on the EQ8 users yahoo group that can initiate the auto-home via a direct connection to the mount - so you could just always run this prior to EQMOD connection.

Chris.