Re: Tracking difficulties


You might want to re-check the N/S switch. It's a 3-way switch - make sure it's hard over on N.


From: ap-gto@... on behalf of chris1011@... [ap-gto]
Sent: Tuesday, 12 January 2016 12:22 p.m.
To: ap-gto@...
Subject: Re: [ap-gto] Tracking difficulties

I am simply guessing because there was not enough information. In my mind trailing can mean 1 arc second error in 30 seconds, or 5 minutes. Trailing can also occur when the motor is turned off. In that case you get 15 arc second trailing in one second (90 arc seconds in 6 seconds of time).
X values quickly exceed 90? What does this mean? 90 arc seconds? That sounds like tracking is turned off completely. You may have plugged in a guider cable that either has a short, or your guide camera is not powered on and therefore sending a signal to the mount to go faster or slower than sidereal.
I would remove all external plugs from the CP3 servo and start fresh with nothing plugged in except the keypad. Forget doing a PEMPro run until you have figured out what software is sending bogus command to your mount. Remove all external cables except the keypad and those going to the motors.
Start from the basics and work your way up to full external control.
-----Original Message-----
From: tom.haugh@... [ap-gto]
To: ap-gto
Sent: Tue, Jan 12, 2016 10:50 am
Subject: Re: [ap-gto] Tracking difficulties


1. The PEM is off.  I attempted a PEMPRO run.  The Y axis values appear as expected.  The X values within seconds, run off the top of the graph.  X values quickly exceed 90.

2. The trailing is only E-W.

3. I am limited to a fairly narrow FOV.  So all my observing is pretty much zenith +/- 35 degrees.

I am concerned with your statement about 30 second unguided exposures being trailed.  I was routinely able to get untrailed 30 second unguided exposures from the mount I am upgrading from.  I couldn't do 60, but 30 was no problem.  Did I just happen to hit the right mis-alignment to accomplish that?  This was using the same telescope/camera/rings/dovetail that is on the 1600 now.  Others on this board praise 5 minute unguided exposures.  Does it take the encoder system to accomplish that?

No argu ment here, I'm just trying to understand what I am seeing.

Thanks for the quick reply.

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