From: "Tim" <tjp314@pacbell.net>

Date: August 27, 2007 9:46:52 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Autoguiding with AstroIIDC

Jim:

I've had this problem with my Tak and my Celestron Nexstar mounts at

various times as well - most recently with the Tak EM-10.

Check to see if your mount has multiple guide speeds.  The Nexstar's

speed settings are pretty obvious, as I (and probably everybody else)

use them to slew to objects, then center in the finder at a slower

rate, then center in the eyepiece of my 9.25 at an even slower rate,

than center on the Flea's ccd at the slowest rate.  

The Tak mount has a number of guide speeds too, but setting them isn't

as obvious - it's some combination of the control pad buttons but

without a display to show you when you've got the slowest setting. 

Last time I tried guiding with my flea and Astro IIDC was at the

Oregon Star Party. I had the problems like you describe - the plot of

the RA and Dec corrections showed the software consistently

overshooting, such that the plot oscillated back and forth past the

centerline.  In fact, I could SEE the star moving back and forth

across the crosshair in the display window.  

Stupid me, though.  I didn't bring my Tak manual with me, or I could

have figured out what button combination to give me the right slew speed.

To illustrate that this is probably NOT an Astro IIDC bug, I've had

the same problem with my Tak mounts when guiding with my SBIG ST2000XM

using EquinoX 5, a prototype Starfish camera and Bob Piatek's software

driver for that camera, and Astro IIDC.  The plots even look similar.

In Oregon, I think I probably also would have needed to shut the mount

down and restarted it to reset it after a change in the guide rate,

but I'm out of town on business now and haven't had a chance to verify.  

Your mileage may vary with your mount, but I'd try something along the

lines of the guide rate setting with the mount/controller first.

Hope this helps,

-Tim.

--- In Astro_IIDC@yahoogroups.com, "jimchung2338" <jim_chung@...> wrote:

Hi all,

I've been trying for weeks now to get my WO GT-1HD mount to autoguide 

reliably with my PGR Flea mono camera and AstroIIDC.  Initialy I 

thought it was issues with flexure which caused my guiding to oscillate 

between overcorrections but I experimented with Craig Stark's PhD 

guiding and it worked very well.  I'd rather stick with AstroIIDC so 

would welcome any experience using it with the SkySensor2000 system.

Setup:  C9.25 with f6 focal reducer and 90mm Meade Mak as guidescope 

(no mirror flop since primary mirror is fixed and focus moves secondary)

Symptom:  errors start to build after a few seconds and there apears to 

be lag in corrections, then over corrections and oscillations.