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CGE dec runaway with flat cables...

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#1 CounterWeight

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Posted 24 June 2009 - 09:29 AM

FYI for CGE users who like me are using the flat cables...

Well I am nine months friendly with the CGE and have again been experiencing dec runaway. Yes I am using the flat or Marty cables, and thankfully ordered spares as I had to change the dec cable this morning. A few days ago when it started up again I just reversed the cable direction and 'seemed' to work... but the problems popped up in various ways...

Symptoms were the same as before. I keep my scope 'home' position close / rough to Polaris, and during find switches,or when imaging the scope wanders off to the East rotational direction, or no longer moves in that direction. Another symptom is that when setting up PHD for tracking I will get the error message something like 'unable to track? in dec mode, turning off dec tracking'...

#2 DaveJ

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Posted 24 June 2009 - 12:44 PM

Hi CounterWeight,

Been there, done that. Bend the edges of the ground shield on the plugs out using an Exacto blade, or similar. Some people place a tiny bit of the sticky portion of PostItNote under the slightly bent-up edge to help maintain the signal flow through the shield. The problem is that you're losing the contact of that grounded plug/receptacle through which the ninth required signal travels between the electronics pier and the motor control board. That simple mod should get you back up and running again. God-awful design/accounting decision if there ever was one. I've got a kit with military connectors, similar to those used on the CGE Pro, waiting for me to install, but I haven't done so yet.

#3 CounterWeight

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Posted 24 June 2009 - 01:27 PM

Thanks Dave,
Thats a new one to me but yes - the 'soup sandwich' design merits some clever tinkering. I'll do it for tonits fun if it doesn't turn greydome - thank you! I have some 'right angle' cable connectors from the same company as the flats... I was going to create my own 9th pin signal as they are 8 pin unshielded. Maybe I'll reconsider that project as well. With a right angle connector the design at least becomes somewhat coherent. I am now again no longer comfortable walking away from this mount during imaging runs as I don't want the TEC to 'whack' a tripod leg while beserking :(

#4 David Pavlich

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Posted 24 June 2009 - 07:32 PM

Here's what I ended up doing to fix the problem.

David

#5 Arbacia

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Posted 25 June 2009 - 05:11 AM

I used serial cable with 9 wires: 8 for the normal terminal pins and one tin solder for the conector shield. Shield problem solved.

However, I am using cable clams. 3-4 for each cable
My adhesive clamps have a shape like that:

_U_

They are simpler than those:
http://www.mcmelectr.../s4/21-3660.jpg

No further problems since I am using both.






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