autoguiding EQ6-help!

[seeker372011 (Narayan)]

Yes, I made absolutely sure that the mount was east heavy. Phil I had the same thought as you did and did play around with the weights to make it even more east heavy , but no joy

(i also went the other way with the weights-making it slightly less east heavy)

[g__day (Matthew)]

Is it over shooting on RA - causing an oscillation?

I ponder are your min pixel movement before a guide command is issued to sensitive. It defaults to 0.20 of a pixel (and can see down to 0.01 Craig told me). However I generally set mine to 0.8 - 1.2 depending on seeing, focal length of guide scope and pixel size of guide camera. The key factor is are your arc/seconds per pixel on your guide scope too sensitive for your viewing conditions. If a pixel is only seeing 0.5 arc seconds and seeing isn't really better than 2-3 well you are going to be over correcting everywhere - and your chart looked like that to me.

I suggest:

Turn backlash to 0 on RA and DEC - definitely let PHD manage this.

Try and adjust pulse length so it takes 15 - 30 pulses to move the star sufficiently to calibrate.

I set RA aggressiveness to about 85% and Hysteresis to about 10%. Purists suggest more aggressiveness (95% - 100%) and less hysteresis (5% - 0%) when calibrating and about my levels when guiding.

Experiment with minimum pixel movement before guide pulse is issued from 0.2 up in 0.1 increments to see where your sweet spot is (seeing based). Definitely use the PHD chart function and look at the Osc(illation) index - you want that as small as can be.

[Babalyon 5]

To use EQMOD, update your hand controller on an older PC with a genuine Serial port(and XP not Vista, wouldnt use Vista at all[my opinion only-don't wanna start a war]) to version 3.23. once you have done then you can use PC Direct mode to control the mount through EQMOD. You also need the latest ASCOM platform. Follow these instructions to use EQMOD when your ready.

1. Open SN (Starry Night 6.23) Or your choice of program with scope control
2. Open Telescope control window of SN
3. Connect supplied cable to hand controller and PC. I have a
docking
station with serial I/O port. (If you have one connect GPS
to PC)
5. Switch on EQ6, select start from Home (parked) position.
6.Enter latitude, longitude,date and time.Continue.
Choose "No" to question "Do you want to start alignment?"
7.In HC choose Utility mode and choose Direct PC.
8.In SN Telescope panel press "Connect" button.
9. This is maybe just my PC but I have to Press Ctrl-key to
activate
the mouse again so I can continue.
10. Select "Setup" from EQMOD pop-up panel.
11. As I use a GPS-receiver I press GPSbutton on EQMOD panel.
Then press "Retrieve co-ordinate and time" button (baud rate
etc
must be set correctly)and finally Accept Data button. Of course
the
co-ordinates can be entered manually and time taken from your PC.
12. Disconnect GPS (just unplug the USB connector)
13. Select alignment (1 Star or N star)
14. I now connect the game pad (rumble pad)and press Initialize
button on EQMOD panel to be sure it connects.
15.Choose alignment star on the SN screen and "Slew to" that star
by right clicking it.
16. Align the star on the telescope haircross using the game pad
and press accept (I do it on the game pad but can be done on the
small pop-up EQMOD alignment window button as well.
17. If needed (N Star) repeat 15. and 16. as many times as you
wish and when ready click "End" button on EQMOD alignment panel.
18. Enjoy sperprecise Gotos if you used N star with enough
alignment stars.
19. To quit press "Park to Home position" on EQMOD main panel.
Wait until scope has parked,. Press disconnect button on SN Telescope
panel. Switch off EQ6 power.

I dont use the game pad yet, but I think I will.

I think pec+sidereal means sidereal rate tracking which incorporates PE corrections.
You could also try to join the EQMOD yahoo user group for support.

[seeker372011 (Narayan)]

Originally Posted by Babalyon 5

(and XP not Vista, wouldnt use Vista at all[my opinion only-don't wanna start a war])

my laptop runs Vista

[seeker372011 (Narayan)]

here's the latest graph..improvement from my last time out but still going over +-3 pixels from time to time in RA...does anyone else have a PHD log they would care to share, so I can compare my mount with others? If you can email me your log please do so at n_mukkavilli-at-yahoo.com.au (i am happy to graph it)
also would anyone have a suggestion as to how to further tame these RA wild swings?

I achieved this improvement BTW by weighting the mount rather more than I am used to in the East--and it brought the RA swings from 8 pixels down to plus or minus 3 .The Dec looks good,course I dont know what the Losmandy brigade would say but its heaps better than my CG5

[seeker372011 (Narayan)]

Originally Posted by g__day

Is it over shooting on RA - causing an oscillation?

Turn backlash to 0 on RA and DEC - definitely let PHD manage this.

Try and adjust pulse length so it takes 15 - 30 pulses to move the star sufficiently to calibrate.

I set RA aggressiveness to about 85% and Hysteresis to about 10%. Purists suggest more aggressiveness (95% - 100%) and less hysteresis (5% - 0%) when calibrating and about my levels when guiding.

Experiment with minimum pixel movement before guide pulse is issued from 0.2 up in 0.1 increments to see where your sweet spot is (seeing based). Definitely use the PHD chart function and look at the Osc(illation) index - you want that as small as can be.

I have set my backlash to zero;aggressiveness-I cant get it to guide unless I go to 110%. My hysteresis is at 10 %-maybe I can experiment with 5%

minimum pixel movement is at default -0.15 from memory-but gee, it does a fine job in Dec..will experiment with this setting too, its one I haven't tinkered with.

gotta ask what's the OSC-I dont seem to have it in my version of PHD?