Still problems callibtrating PHD

[decoyp]

I Still require a bit of help geting PHD to work. If anyone can give me some more advice it would be greatly appreciated. Here's the setup......

HEQ5 set up on a permanent mount and carefully drift aligned.

I'm using a QHY5 camera on a 400mm telephoto lense as a guide scope piggybacked on a skywatcher equinox 80mm scope for imaging. The problem is when I try to set up PHD to guide I can't seem to get past the callibration steps. I keep getting the message "star did not move enough" . I've tried changing the pulse duration for a shorter focal length guide scope and upping the exposure time but tonight I couldn't get more than 10pixels movement in 60 callibration steps. PHD requires 25 to callibrate.

Would I be better picking a quide star closer to the horizon ? Is it a good idea to have a guide star not in the region of where you want to image? (probably not I suspect).

Also is it possible that I am too well polar aligned in the first place (I find this hard to believe too). Perhaps if I deliberately misalign the mount a bit PHD would see more drift. This seems like defeating the object though.

Any suggestion greatly appreciated.

Cheers Richard

[Glider]

Have you got your duration turned up, for my finderguider with 200mm focal length is goes as high as 2000ms.

[Steve 1962]

I agree with Glider - click the Brain button and turn the "Calibration Steps (ms)" setting up as he suggests - it's nearly always worked for me

Steve

[decoyp]

I have tried turning the duration up as far as 2000 and down as far as 50 but it doesn't seem to make a massive amount of difference. Will try again tonight weather permitting. Does it go up further than 2000? I also set the exposure higher to string the callibration process out over a longer period (4.5s) that makes a difference, but not enough.

Cheers richard

[Merlin66]

I have exactly the same set up and only use the default settings.

You could try changing the Synscan guide rates in the handcontroller to x1 siderial rate.

Also double check the cable connections between the camera and the mount ( I found - don't ask me why! - I had ended up with the wrong cable it needs to be an ST-4 cable pin 1 to pin 1)

[jgs001]

I had to make the calibration step 3000 with the 5v and ST80 (400mm) clone. The calibration has to move the mount a certain distance in under 24 steps (I think it is) and it's not moving far enough. I'd keep increasing the step distance (say in 200 increments) until it works.

[Psychobilly]

You can use the virtual handbox in PHD to make sure that the guiding "Connections" are working propely...

[decoyp]

Cheers Guys, I'll give these suggestion a go. I was wondering about the cable too. Where can I purchase the correct link cable from? I'm using a cable that I found lying around that appears to fit but it may not be correct.

[Merlin66]

Astronomiser sell the ST-4 cables in various lengths.

Astronomiser - Automated Astronomy and AstroImaging Solutions

[adamsp123]

As others have suggested it could be the cable, mine went through a phase of calibrating in RA but not DEC, turns out the ST4 cable had corrosion on the terminals, got some excellent ones from Astronomiser (who provide a range of cheap but well put together cable) never had a problem since.

[dmahon]

I just received mine today , along with an EQDIR module, finderguider and a few other bits. I managed to set it all up and had CdC moving the scope around straight away. PHD got an image, but it wouldn't calibrate, just like your setup.

I turned off sidereal motion and then it did move, but it was as iff the mount wasn't receiving any guiding signal - the stars just moved slowly in a uniform direction (eventually going off the screen). I turned off CdC too - no effect.

Took me half an hour to figure out the problem I had - I had the scope setup in PHD as "ASCOM" - it obviously needed to be set up as "on camera". CdC talks to the scope via ASCOM, but the camera is conected directly to the mounts' ST4 socket, the signalling is not going via my laptop.

Probably made more confusing by the use of ASCOM QHY5 drivers for PHD to talk to the camera.

[beamer3.6m]

Probably no help but I had a hot either dirt or a dead pixel which I tried to calibrate on.

You can guess the result was not great.