having guiding problems

Alan Voetsch <alanv12952@...>

Hey all,

Still getting familiar with the new 1200 which arrived in late Oct. Had a few
opportunites (weather has sucked since mid-Sept) to use the FS-102 for a few comet shots
and managed to do the meridian delay alignment routine. There were no problems during
this time, other than operator errors.

My 12" LX200 'R' OTA arrived about 10 days ago. At this point it is balanced in both
axis', and OTA is collimated. Last night had some clearing so i tried to image the HH. I
am shooting film (OM-1) at prime focus and using a standalone ST-4 (no computer in my
observatory) and Taurus Tracker III OAG to guide.

All attempts to guide failed until I did the calibration at 0.5 speed, and guiding at
0.25. These settings worked for about 90 minutes, then the guidestar was lost. Actually i
think it's more a case of the ST-4 moving the GS TOO much, until it's off the chip. I may
try .25 for both next chance I get.

I plan to check RA and Dec backlash to see if either of those are a problem. I did not
stay out in the observatory the whole time, but I did notice that there were some large
spikes where the correction indicated was 'E' for a couple times, then it would settle
down to 1-4.

This OAG and ST-4 have worked well with the previous scope, a stock 12" LX200 classic.

So, I'm hoping that someone who has used a similar setup may have some areas for me to
check. Like I say, I am used to setting the the ST-4's parameters for a fork mounted
LX200 and possibly I am using a setting incorrectly. Last night i used 5 second exposure,
boost of '2', average, no backlash adjustment, cal '3' both ways, scintillation '4', and
a correction after each exposure.

Any suggestions?


Astrophotography: http://www.pbase.com/avoetsch12952

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