QHY9 mono specs

multiweb (Marc) · #1 02-08-2011, 05:04 PM

Hi guys, starting to ask a couple of questions as I just got a QHY9 mono.

1_ I understand the CCD chamber is sealed so does that mean the camera can be run without a glass nosepiece.

2_ I read here that the distance between the CCD surface and the M42 thread is 15mm. I measured 6mm from the camera face to the sealed chanber glass. So this means the CCD is only 9mm below that window? So 15mm all up? Or is it 15mm from the chamber glass?

3_ The QHY8 distance from CCD to camera face is 6mm. If the AHY9 is now 15mm can I still use the QHY8 adaptor on the Hyperstar for the C11. Any of you guys image with a QHY9 with an hyperstar 3? Did you get another custom adaptor.

That's all for now. Thanks for any pointers.

Marke (Mark) · #2 02-08-2011, 05:51 PM

Marc I have a qhy10 with the glass front, not sure if yours is the same
but if it is then its N2 purged and sealed with a little screw on the side.
If moisture gets in there was a supplied desiccant chamber with mine
that goes on in place of this screw in order to remove moisture. Then you
put the screw back to seal it. The glass should be left on the front to seal it
and protect it from frosting.

multiweb (Marc) · #3 02-08-2011, 05:56 PM

Quote:

Originally Posted by Marke

Marc I have a qhy10 with the glass front, not sure if yours is the same
but if it is then its N2 purged and sealed with a little screw on the side.
If moisture gets in there was a supplied desiccant chamber with mine
that goes on in place of this screw in order to remove moisture. Then you
put the screw back to seal it. The glass should be left on the front to seal it
and protect it from frosting.

The QHY10 is a different design again. There's a dessicant plug for the QHY9 too. I just want to know if it's ok to run the QHY9 with the main camera body to ambient air.

Marke (Mark) · #4 02-08-2011, 05:59 PM

From my understanding doing that will cause it to frost over as the ccd is directly exposed to the air which would not be a good thing.

multiweb (Marc) · #5 02-08-2011, 06:21 PM

Quote:

Originally Posted by Marke

From my understanding doing that will cause it to frost over as the ccd is directly exposed to the air which would not be a good thing.

The CCD itself is in a sealed chamber so you mean the chamber window might dew up then? The CCD is never in contact with ambient air whether the camera body is open or not.

Marke (Mark) · #6 02-08-2011, 06:26 PM

Yep thats what i meant Marc sorry , isnt the glass front on the qhy9 heated to
stop dewing ? With out that it would most likely dew or frost
over I would have though.

multiweb (Marc) · #7 02-08-2011, 06:30 PM

Quote:

Originally Posted by Marke

Yep thats what i meant Marc sorry , isnt the glass front on the qhy9 heated to
stop dewing ? With out that it would most likely dew or frost
over I would have though.

Not sure what gets heated. The nosepiece glass or the sealed chamber front glass. Doesn't say in the manual but you're right I've read somewhere something gets heated.

Marke (Mark) · #8 02-08-2011, 06:34 PM

I think its the front glass cover that gets heated not the glass protecting the CCD

multiweb (Marc) · #9 02-08-2011, 06:36 PM

Quote:

Originally Posted by Marke

I think its the front glass cover that gets heated not the glass protecting the CCD

Damn... If I have to keep the nosepiece in place I'm going to have work out all my spacings again.

Marke (Mark) · #10 02-08-2011, 06:39 PM

I dont envy you there

marki · #11 02-08-2011, 10:06 PM

Hi Marc

The distance from the chip to the front face of the camera is 15mm. The nose piece adds 12mm to give you 27mm from chip to front of nose piece. This is without taking into account the extra distance added by the glass filter in the nose and the glass plate that covers the CCD chip itself (some argument over whether its relevent or not but I dont bother and my spacings work fine). The camera will run happily without the nose piece with the only difference being a higher TEC draw to achieve required temps. The CCD chamber is sealed and nitrogen purged and as I read it this is a seperate entity from the space sealed by the nose piece. The heating ring sits on the top board (nearest the camera face) and warms the air in front of the CCD chamber to prevent dew forming on the UV/IR filter mounted in the nose piece. You can also use the desicant plug if need be. Hope that helps.

Mark

multiweb (Marc) · #12 03-08-2011, 07:36 AM

Quote:

Originally Posted by Marke

I dont envy you there

Well I opened it and it looks like the heater is located under the board next to the sealed chamber window so that's fine. Pfweehh...

multiweb (Marc) · #13 03-08-2011, 07:49 AM

Quote:

Originally Posted by marki

Hi Marc

The distance from the chip to the front face of the camera is 15mm. The nose piece adds 12mm to give you 27mm from chip to front of nose piece. This is without taking into account the extra distance added by the glass filter in the nose and the glass plate that covers the CCD chip itself (some argument over whether its relevent or not but I dont bother and my spacings work fine). The camera will run happily without the nose piece with the only difference being a higher TEC draw to achieve required temps. The CCD chamber is sealed and nitrogen purged and as I read it this is a seperate entity from the space sealed by the nose piece. The heating ring sits on the top board (nearest the camera face) and warms the air in front of the CCD chamber to prevent dew forming on the UV/IR filter mounted in the nose piece. You can also use the desicant plug if need be. Hope that helps.

Mark

Thanks for the detailed explanation Mark. So that's only 9mm deeper than my QHY8 sensor which was 6mm from camera face. That is going to make life much easier as I can make up for the gap easily. I wasn't too sure if the QHY9 could be run without the nosepiece but it seems that it's quite ok. Removing the 12mm nosepiece leaves me with the 15mm that I can play with.

I'll have to chat with Theo to see if mine was nitrogen purged. In the end dessicant strips and regular inspection of the contact pins are the way to go. My QHY8 is 4yrs old now and still working perfectly without a hint of corrosion because I've always opened it up after each session and dried it out before storing it.

I have it working fine in Neb2 and Maxim DL 5.x as an Ascom camera. I was shooting some darks and playing with the TEC on the bench last night. Temp control is new to me so I'm experimenting. When you set the cooling point in Maxim to let's say -10c it goes down to -20c or less. It also fluctuates a lot +/-7c. Is this normal? I thought the regulation would have been within +/- 1c ? Or does it need time to settle down?

I used Gain 1 Offset 60 and apart for hot pixels 10min darks were ink black. No noise. I couldn't even stretch the data. So I think something's not right. The camera is working because if I do a 1s exp without the cap on I get saturated white. I just thought it was odd to have hardly any signal on a 10min dark. Maybe gain1 is too low. What do you use?

mill (Martin) · #14 03-08-2011, 08:16 AM

Hi Mark i use gain 3 and Offset 112.
Maxim keeps the temp +/- 0.5 C on my setup and when i set it on -20 it goes to -20 no more and no less so it is not normal that you have a large fluctuation and the temp goes to -20 or more when it is set to -10.
I am not using nitrogen (just warm air while assembling) and never get the chip frozen over.
You better talk to Theo about this strange behavior, it might be something simple.

multiweb (Marc) · #15 03-08-2011, 08:33 AM

Quote:

Originally Posted by mill

Hi Mark i use gain 3 and Offset 112.
Maxim keeps the temp +/- 0.5 C on my setup and when i set it on -20 it goes to -20 no more and no less so it is not normal that you have a large fluctuation and the temp goes to -20 or more when it is set to -10.
I am not using nitrogen (just warm air while assembling) and never get the chip frozen over.
You better talk to Theo about this strange behavior, it might be something simple.

Thanks Martin. I'll do some more testing today then contact him.

Something's definitely fishy. If I set the point to 0c the TEC will kick in and get the camera down to -28c then the TEC will go off, the Camera will slowly warm up again until it passes 0c then the TEC will kick in again at 3c and bring the camera back down to -28c again. So wether it doesn't regulate properly of Maxim is giving me incorrect readings?

See attached snapshots.

I'm doing this indoors so ambient is approx 20c.

mill (Martin) · #16 03-08-2011, 08:41 AM

It is Martin, but you can call me Rob

multiweb (Marc) · #17 03-08-2011, 08:55 AM

Quote:

Originally Posted by mill

It is Martin, but you can call me Rob

Sorry mate. I'm talking to too many people at the same time.

mill (Martin) · #18 03-08-2011, 09:01 AM

No worries, here is a site explaining gain and offset http://www.stark-labs.com/blog/files/GainAndOffset.php

multiweb (Marc) · #19 03-08-2011, 09:05 AM

Quote:

Originally Posted by mill

No worries, here is a site explaining gain and offset http://www.stark-labs.com/blog/files/GainAndOffset.php

Thanks mate. I have no problem with Gain/Offset settings at this stage. Regulating the cooling in Maxim DL is the issue.

It goes up and down the full range from ambient down to maximum cooling then does it again and again even when I start the warm up sequence at the end. It reaches ambient then the TEC kicks in again full blast. This is very very weird. I don't know if it's a software issue at this stage or a hardware problem with the QHY9.

Power supply is a steady regulated 12.2V input from a lab power supply at the moment.

multiweb (Marc) · #20 03-08-2011, 09:20 AM

Narrowed this down to the ASCOM driver. So software issue I think at this stage. Even with Maxim DL disconnected and off the TEC kicked in again from Neb as soon as I connected the QHY9 via the ascom driver. Even with TEC unchecked. When I pressed OK I saw the CAM drawing amps on the power supply straight away so I assume starting cooling as the TEC led turned on on the DC102. Downloading the latest ascom platform 6 now and will try again. Joys of new gear...