Re: AP 900 problem
William R. Mattil <wrmattil@...>
Michael Cater wrote:
I have had no problem with the ST4 calibration mode. The problems develops after a few minutes of guiding and then the accuracy drops off. I will try my friend's ST4 to see if the problem is duplicated; if his works then my ST4 is defective.Mike,
It is extremely doubtful that your ST-4 is defective. The scenario that you describe isn't at all uncommon and the root cause of it is that the parameters selected are not appropriate. Just because you successfully calibrate is no guarantee that the guiding will be successful. You haven't provided nearly enough information for anyone to actually help you with this either. I would suggest that you check the group archives as Roland has explained the mount parameters needed a number of times. Then it is up to you to provide the following.
1) A known good Autoguider Cable
2) Accurate Polar Alignment
3) Reasonable Parameter Settings for the ST-4.
I can assure you that both of my ST-4's worked well with my AP900 Mount.
The situation that you describe indicate that the feedback loop is out of kilter. Assuming that the Polar Alignment is good enough.
William R. Mattil : http://www.celestial-images.com