PHD advice

graham.hobart (Graham stevens) · #1 19-08-2011, 08:44 PM

Right, I set up and watched the graph, both axis stayed pretty much on baseline till about four minutes then the dec graph started to climb off the scale- why is that?
Can still see the guide star but it's not centred anymore-RA graph remains on line
Help please..
Graham

jjjnettie (Jeanette) · #2 19-08-2011, 08:54 PM

I had similar problems, mine ended up being due to a loose cable in the back of the QHY5 causing intermittent signals to be sent.
Other causes?
it could be your balance is out or your drift alignment isn't the best and the camera can't keep up with it,

graham.hobart (Graham stevens) · #3 19-08-2011, 09:10 PM

just tried again and it said can't seem to move mount in dec so turning off dec guidiing? loose connection?

multiweb (Marc) · #4 19-08-2011, 09:13 PM

Try closing PHD and re-calibrate then guide again.

jjjnettie (Jeanette) · #5 19-08-2011, 09:18 PM

Yeah, the socket at the back of the Qhy5 wouldn't hold the cable in place securely.
Nearly ended up frying my chip.
It was strange though, as PHD would keep on working. It wasn't until the camera stopped working altogether that I realised what the problem was.
8 months of frustration, solved, just like that.

jjjnettie (Jeanette) · #6 19-08-2011, 09:19 PM

am using a Phillips spc900 in the mean time through a borrowed GPUSB and it's guiding like a dream now

graham.hobart (Graham stevens) · #7 20-08-2011, 08:43 AM

JJ, I have a modified philips (from IIS) but don't have the serial connection to do longer exposures.
Question- do you run the philips with PHD and GPUSB as a shorter exp guide cam?
If this is so I could probably try that as I have a GPUSB unit somewhere.
Would that be on camera control or GPUSB on the PHD drop down menu, set exp to ? 1-2 secs and find a star?
Please let me know how you set yours up as guiding has been my bugbear for months & months

Many thanks
Graham

jjjnettie (Jeanette) · #8 20-08-2011, 09:46 AM

My webcam is not modified for long exposure.
In PHD, camera connection , choose, "Window WDM style web cam"
I use the default 1 sec exposure time.
What are you guiding through?
I was using an iOptron 80mm F5, and sometimes finding a star was a bit of a hassle.
No problems at all though, with the little finder guider that ponders and I knocked up.
Just remember to go into the Camera Dialogue and turn off the automatic settings and adjust your gain etc accordingly.

graham.hobart (Graham stevens) · #9 20-08-2011, 10:24 AM

I just bought one of those mini finderscope guider things from Bintel sounds similar. Though I also have a Stellarvue finderscope I could try.
sounds promising- will let you know how I get on. But probably not this weekend as I made plans for observing and thus have cursed the weather to interminable clouds again!
Yet again my weather ruining prowess astonishes me- ten points to Slytherin!

mswhin63 (Malcolm) · #10 20-08-2011, 06:14 PM

Hi Graham, I am also interested in one of these for guiding, let us know how they go. I am a bit skint at the moment so I don't want to buy things unless they are really tested well.

graham.hobart (Graham stevens) · #11 20-08-2011, 07:45 PM

Won't be doing much guiding tonight unless its with a guide dog!
Here's a picture across from my deck at 4pm this afternoon.
As can be seen the clouds are at tree top height!
Curses!
Graham

jjjnettie (Jeanette) · #12 20-08-2011, 07:59 PM

LOL Well I packed my mount up and bought it inside because of the clouds. Clear as a bell now.
LOL Put the camera on a tripod and am making star trails instead.

graham.hobart (Graham stevens) · #13 23-08-2011, 07:41 PM

Well I re-aligned scope and got a flattish graph in both axis for about five minutes.
But when I attached DSLR it went off after about 1 minute so I assume my OTA balance is off with the camera.
Question- with my Meade APO 80mm on a short dovetail plate with guidescope rings- anyone know how I can balance the objective end of the tube as I assume the camera + guidecam (SSAG) and finderscope are pulling the back of the tube down.
I guess I need more weight at the front end but the mounting plate I have for the cgem is quite short-i.e no shuffle room to move weight of scope forwards etc.
Outside of getting a custom made plate made which is longer- can you get weights that attach to any scope?
I have some meade SCT weights but they slot onto a guide rail specific for the LX 90. Fishing weights and velcro?, one of Sadie's overnight nappies? (pretty darn hefty!)
Cloud dodger Graham

A23649 (Nathan) · #14 24-08-2011, 03:58 PM

you could probably get a longer dovetail bar made up cheap at bunnings or someplace like that i know that is what i am doing for my guide scope bar