Auto-Guiding With the DMK

gbeal · #1 24-09-2009, 02:19 PM

OK, I have been auto-guiding for a while so am not completely new here, but am wanting to try something slightly different, and need a little help with the "need it" list.
I have always used the QHY5 and am looking at using soon the SX Guide-head, with the CGE and whatever imaging scope I use at the time.
Software is Maxim DL normally.
Now, if I want to use instead the DMK (firewire) and PHD, what other cables do I need? GPUSB?? Can I make one of these (miserable), and if so where do I find the diagram?
No doubt others have asked, and there will be all the answers I need out there, just a matter of pointing me in the right direction.
Gary

bmitchell82 (Brendan) · #2 24-09-2009, 02:24 PM

Gary, just for your help, do not use the DMK... they arent cut out for the job aka arnt sensitive enough use your QHy5 it will far out proform the DMK.

If you can connect the mount up Using EQ Mod, then all you need to do is get the picture from the camera back to PHD, PHD will send the guide commands though EQ Mod as pulse guide commands. just a thought as you can trim the pulses though EQMod to be exactly how you want.!

gbeal · #3 25-09-2009, 07:48 AM

Hi Brendan,
thank you. I was convinced others had used the DMK though, but with the lack of replies it is hard to judge. The QHY seems to go well, so maybe I'll just sit tight.
I don't have EQMod though, the mount is a CGE.
Gary

iceman (Mike) · #4 25-09-2009, 07:53 AM

Sorry gary, I was going to reply the other day but thought others would chip in first

I use my DMK for guiding and it does a great job.

I use GP-USB and PHD in combination with the DMK to guide my EQ6.

mtodman (Matt) · #5 25-09-2009, 08:15 AM

Hi Gary,

I purchased a USB - ST4 adapter from teh following website
http://home.comcast.net/~lynol1000/g.../guide_out.htm

It works very well. You can purchase it fully made up or in kit form.

Cheers

Matt

gbeal · #6 25-09-2009, 08:43 AM

Cheers guys, I was sure others had success different to what Brendan had suggested. I am torn between sitting with the status quo, or trying the DMK.
The Scrooge in me wanted to build a cable, but given the details from the link Matt supplied it could be beyond me.
Gary

wysiwyg (Mark) · #7 25-09-2009, 10:10 AM

Gary,

I have used a mono DMK for guiding for years now, and I have never had a problem guiding with it, light polluted or dark skies its a great little camera. There are definitely better ones out there, but after all we are discussing the DMK here.

Quite a few people seem to think the DMK is not good for guiding, but through my experience its about tweaking the camera settings in the software to get a nice guide star, there is nothing wrong with the DMK.

I would suggest going for the USB version, as the Firewire version requires its own power supply.

Cheers
Mark

gbeal · #8 25-09-2009, 10:49 AM

Thanks Mark, and all the others that have made suggestions.
Mark, I already have the firewire version anyway, and as a Mac freak, there is little better than firewire anyway. In fact unless I am mistaken, the only IS cameras that work with PHD are the firewire ones anyway.
So, that settles it, I'll try it. But the consensus now is I need a cable, correct? Something fit fit between the PC (USB or Serial) and the mount (RJ11). GPUSB or the one listed above in Matt's post. I would still like to build my own if possible, any ideas?
Gary

[1ponders] (Paul) · #9 25-09-2009, 01:04 PM

Gary I used the DMK with great success. My setup was Laptop/pcmcia (powered)/DMK and Laptop/GPUSB/RJ12 (aren't they

)

Alternatively I went laptop/pcmcia/powered hub/dmk

Bother setups worked a treat with PHD.

wysiwyg (Mark) · #10 25-09-2009, 04:00 PM

Quote:

Originally Posted by gbeal

Thanks Mark, and all the others that have made suggestions.
Mark, I already have the firewire version anyway, and as a Mac freak, there is little better than firewire anyway. In fact unless I am mistaken, the only IS cameras that work with PHD are the firewire ones anyway.
So, that settles it, I'll try it. But the consensus now is I need a cable, correct? Something fit fit between the PC (USB or Serial) and the mount (RJ11). GPUSB or the one listed above in Matt's post. I would still like to build my own if possible, any ideas?
Gary

Gary,

Yes you will need the GPUSB, which will plug into a USB port on your laptop/desktop and the other end plugs into the RJ11 guide port on your mount (No serial to USB required).

Shoestring sell both the GPUSB and the cable.
Have not seen a home made version of these so I cannot comment, but I would say its not worth the hassle.
PHD works with both USB and Firewire DMK's, that's what I have been using with my DMK.

Cheers
Mark

mtodman (Matt) · #11 25-09-2009, 07:54 PM

Gary,

Do you have a parallel port on your PC? If so, it's very easy to build a Parallel - ST4 interface using optocouplers. I built one that works fine (just configure your sw to look for a GPINT-PT). Let me know & I'll see if I can scrounge up the circuit diagram.

Matt

gbeal · #12 25-09-2009, 08:01 PM

Matt,
I do, it is a desktop, so yes it has the parallel port.
Can you point me in the right direction for what I need etc?
Gary

mtodman (Matt) · #13 25-09-2009, 09:45 PM

Hi Gary,

Pls see attached link.
http://www.astroromp.com/astronomy/V...one%204N25.pdf
I bought the parts (including the breadboard) from dick smith electronics.

Matt

gbeal · #14 26-09-2009, 06:57 AM

Hi Matt,
thank you again for all this. I will take this to my electronics guru and see what we can make of it.
Regards,
Gary