Quote:
Originally Posted by multiweb
I'm revisiting the way I've been doing my auto-guiding. It worked well for me so far but I'm looking at possibly more efficient ways to do it and minimise all the cables hanging off my scope.
At the moment I use a QHY5 [Q-guider] plugged into a USB hub (x4) to the laptop USB2.0 port. I run PHD with the Ascom Gemini drivers. From PHD the guide ouput goes throught the same USB port back to the USB hub then from USB to serial then to a custom made cable serial to RJ11 into the RS-232 port on the Gemini. This works well but still I noticed tracking goes a bit wacky when I use the same USB pipe while downloading the pictures from the camera to the laptop.
I also have a GPUSB-AH which I have tried in a similar fashion with a straight RJ12 cable to the auto-guider port on the gemini. I haven't tested this on the field but on a bench DEC and RA motors respond to the pulses sent so I assume it'll work for tracking.
What I would like to do is plug the QHY5 guide ouput right into the gemini auto-guider port. So far I have crimped one end of the cable, tested and I have approx. 5V on both pin1 and pin2 of the cable right out of the Gemini auto-guider port. As per wiring diagram my understanding is that pin2 is the common ground. Pin1 [usually not connected] may be the power pin in some mounts. Sounds like it is in mine. But I also get 5V on pin2 so that's what made me a bit nervous. 
Anyone wired an old gemini box to a QHY5 in a similar fashion? What did you do with Pin1 and Pin2?
Most importantly is there any real advantage or performance gain in using the QHY5 guider output?
I read a few threads on this forum so I'm pretty sure some of you are already doing it but I couldn't find any definite wiring diagram.
Thanks for any hints. |
Hi Marc,
PIN 1 is not used. You got 5v because the PIN2 is the common or ground and PIN1 carries voltage for a different purpose which has not yet been specified.
PIN 3,4,5 and 6 are the guiding pins. Take a look into the Gemini Instruction manual located here
http://www.docgoerlich.de/manL3V11/GeminiUserManual.pdf page 92
There is one thing that the voltage of the old Gemini GoTo control box is a negative voltage and not a positive voltage like in the new Gemini GoTo box.
Pin 2 is the common and the pins 3,4,5 and 6 carry -5v when measured against common = PIN2
I do not know how the output of the QHY8 is but you should be carefull not to fry anything.
The best thing is to use the GPUSB-AH you have.