Sbig St-5c Help Needed

[solissydney]

I have a problem with the above equipment linking with the camera using CCDOPS ver 5.
Can anyone assist?

[Dennis]

Is that the model that connects to a black box using 25 way parallel connector, then the black box connects to the mains power adapter and the computer using a 25 way parallel connector?

Cheers

Dennis

[solissydney]

Thanks Dennis. The laptop connects to the big black box with a parallel cable. The box then connects to the AUX autoguider connector on the Ultima with a 6 wire cable with telephone connectors.

[Dennis]

I used to have the Celestron re-badged model, the PixCel 255 some years ago.

As it is a single chip CCD, I assume you are trying to use it as an auto guider from your description?

Cheers

Dennis

[solissydney]

Yes, I do intend using the ST-5C as an auto guider with my Celestron Ultima.
One problem I am working on is that the 6 wire telephone cable gets hot when plugged into the scope. I have changed parallel cable to no awail. The software still can't 'see' the camera.

[Dennis]

Okay, first thing, don’t continue to plug in the 6 wire telephone cable – it should not get hot.

As far as I know, these cables are “signal cables” for carrying small, very low power signals between mount and guider. Heat indicates that you have too much power going through, such as the power to drive the mount, which is typically 1 or 2 amps at 12V DC.

This suggests that maybe, the wiring or cable is incorrect, as that kind of power should not appear in a signal cable.

I say maybe, because I had a hot auto guide cable once due to a circulating earth problem; a heat sink had slipped inside the mains adapter and was now touching the metal outer case so power that was going to the mount was somehow circulating in the auto guider cable. Fortunately, no damage was done.

Cheers

Dennis

[JohnG]

As far as I am aware, you require an SBig Relay Adapter Box between the mount and the guide cable, unfortunately, you may have already damaged the wiring if it has gotten hot.

The relay box electrically isolates the mount, see here:

http://www.astrovid.com/technical_documents/Losmandy%20SBIG%20Compatability%20I ssues.pdf

Specifically mentions the SBig ST5c just over half way down.

Also, are you running the latest version of CCDOPS and have you downloaded the latest SBIG Drivers.

Cheers

John G

[leon]

I always thought and I was made very aware of this the 6 pin telephone cable, although it looks the same is not to be used as it will cause problems.

You must get the proper connecting cable from specialist suppliers.

Please correct me if I'm way out of order here.

leon

[Dennis]

I’ve just had a look at the SBIG ST5 manual on the SBIG website (http://www.sbig.com/sbwhtmls/softpage.htm)and it reads (on Page 22):

"To autoguide you need to connect the camera's Telescope port to your telescope's CCD input. On Celestron Ultima, Losmandy and LX-200 mounts this is accomplished with the small 6 conductor "telephone" cable provided with the camera. Simply plug one end into the Telescope port on the camera's CPU and the other end into the telescope. On Ultima and Losmandy mounts you will need to unplug the hand controller and plug the auto guiding cable in its place. On the LX-200 you plug the cable into the CCD jack. Finally if you have an older telescope that does not support the 6 pin CCD port contact SBIG Technical Support and inquire about custom hand controller modifications and whether you need an external Relay Adapter box."

So, is your cable the same “small 6 conductor "telephone" cable provided with the camera” or is it e.g. a telephone cable purchased locally?

Cheers

Dennis

[solissydney]

Yep, looks like I will need a relay box to make the guider work with the Ultima. So much for the SBIG instructions that tells you to replace the hand controller 4 wire plug with the 6 wire one, ??? I didn't understand that. I have been using the autoguider port on the Ultima that is sits next to the hand controller port. Is it possible to get a 6 wire small cable plug? ( I wonder) I have downloaded the latest CCDOPS drivers.The telephone cable came with the guider I purchased from Steve.
Thanks for your support

[Dennis]

One useful mini project is to get the Celestron Ultima and SBIG ST5 manuals and locate the figures that describe the auto guider connections. Then, I would test the telephone cable to make sure that it is the correct cable, using a multi meter to verify the wiring configuration.

It seems that some auto guider cables are straight through, whereas others are ‘cross-over”. It is worth determining that you have the correct cable so that you can at least discount that piece of gear as potentially contributing to your problems.

I am still puzzled by the heat in the auto guider cable? I am not an electrician and my somewhat limited knowledge has been gained from building my own auto guider and RS232 GoTo cables for the Vixen GPDX and Tak EM200 mounts. I found the information generally quite difficult to come by and struggled with whether the info was referring to the Plug (boy), Socket (girl), Jack (girl?), etc! not to mention the colour coding of the inner cables, which in the end, I simply ignored and followed the pin numbers instead.

Cheers

Dennis

[allan gould]

If push comes to shove I may have an sbig relay adapter box available. I have gone through a similar problem with my losmandy mount but am getting an optocoupler repaired as we speak. If the repair is sucessful then the relay box will be available. PM me if you require going down this route.
Regards, Allan

[solissydney]

The cause of my problem found.
But firstly, the 6 wire telephone cable matches the CCd port on the Celestron Ultima, in other words, the connection should be straight forward, no relay box needed. The cause of the problem is a short circuit on the circuit board. The fuse was blown, A friend of mine, an electronic engineer tested the unit for me and found the cause of the problem.
Thank you all for your interest
Ken

[Dennis]

That’s good news indeed Ken. I trust nothing was fried or damaged?

Cheers

Dennis

[solissydney]

No Dennis, it is not good news. Luckily the scope is ok Dennis. The good news is that I have been promised my money back on the guider.
Thanks again all.