In late April, I was informed by Helmar Adler, the telescope advocate for BSM HQ, that the desiccant was starting to fail on the ST-8XME camera. I went down to HQ on April 30 and inserted a replacement desiccant cylinder that I had baked for a short time (wasn't there long enough to do a thorough job). Unfortunately, it seems that the replacement was worse than the original, and so most of the data from May 1 through May 10 is compromised. The effect is moisture condensation as a "picture frame" around a central portion of the chip that is reasonably ok. Usually such moisture evaporates through the night, but if you are using flats made at dusk when the effect is the worst, then the applied flats continue to compromise later images. I may be able to recover some of the data if dawn flats are available; I'll let you know if that works. However, there are more urgent AAVSOnet tasks right now, so it may be a week or two before I can reprocess this data window.
Starting on the 11th UT, a new cylinder was installed that was properly baked and seems to be working fine. However, astrometry.net is down; a wonderful web-based plate-solving program that is nearly essential to getting BSM started at the beginning of the night. Helmar and I are working on alternatives so that the clear nights that we've been getting can be used!
Arne
For my own aging ST-8XME, I replaced the SBIG desiccant plug with Farpoint Astronomy's plug, which accepts standard 3-gram silica gel packets (available from them, or very cheaply elsewhere). I just remove the old and insert the new packet, so that exposure of camera internals to the outside air is very brief indeed. It may not last quite as long as does baking SBIG's original plug, but it's fast and certainly straightforward (and no second trip to the camera). Just a thought...
Will the Farpoint Astronomy plugs work on SBIG STL cameras like the STL-1001e? Alternatively does SBIG sell replacement plugs for the STL line so I can have a spare since my telescope is remote and there is no over available there?
Thanks,
Frank Schorr SFRA
Hi Eric!
We've installed the Farpoint system on three of the AAVSOnet telescopes, and I agree that it works well (especially for BSM_Hamren in humid Hawaii!). We should probably upgrade all of the SBIG cameras to this system before they are no longer available! That is a $500 expense that will take a surplus in the AAVSOnet Fund to make, as right now the fund is so low that I'm more worried about any potential repairs for the rest of the year.
Thanks for reminding me about the Farpoint system!
Arne
[quote=HQA]
That is a $500 expense that will take a surplus in the AAVSOnet Fund to make, as right now the fund is so low that I'm more worried about any potential repairs for the rest of the year.
Thanks for reminding me about the Farpoint system!
[/quote]
The Farpoint "system" is just a short threaded metal tube that fits into the CCD housing, with a cap on the other end. Maybe we could do this more inexpensively by just DIY it? The Farpoint is quite overkill at $68!
From what I can see, we would only need the following OTS hardware to DIY this plug:
1. 7/16 - NC(?) Die
2. 7/16 x .065" wall aluminum tubing for the threaded part
3. 5/8 x .035" or 3/4 x .035" aluminum tubing for the desiccant plug itself
4. Plastic cap to fit the plug end.
5. Epoxy to join the two segments.
These common parts could be obtained for a couple of dollars on ebay, etc.
Mike
FYI,
Astrometry.net is back up and running normally.