On Sun, Jul 19, 2020 at 10:49 AM, Dave Cherry wrote:

Does this new firmware have any advantages if you are pulse guiding with a guide scope?
I haven't upgraded yet as it is working fine for me just as it is.

Hi Dave,
There have been no significant changes recently to the pulse guiding code, but there is a significant change that impacts the performance of the slews that you 
would definitely want to have.
 
--
Jerry Hubbell
Vice President of Engineering
Explore Scientific, LLC.
jrh at explorescientific.com
www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home


Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
Mounts: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating
Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!

On Jul 18, 2020, at 9:31 PM, Vince White <vnwhite@...> wrote:



Hey Jeff,

I have a couple of quick comments on lightening your battery pack:

If you haven't actually measured the running wattage of all of your equipment, you might be surprised by how little something consumes versus the rated wattage of the AC-DC adapter.  Something like this is convenient to measure the running wattage of individual equipment, and generally handy around the house.  You might find that your total running wattage is lower than you think and that the 114AH battery may be oversized, certainly 70# is a lot to drag around.  Depending on your laptop and OS, you should be able to enable power-savings and significantly reduce its running power consumption. 

Also, I suspect that most, if not all, of your astro gear is DC powered.  Doing a conversation from the lead-acid 12VDC to 120VAC with an inverter, then back to DC via the individual AC-DC adapters is not very efficient.  Ideally you would just use the 12VDC of your battery straight to your devices (like the PMC-Eight) or do a 12VDC to DC conversion using boost or buck converters, which are very efficient (~90%).  The downside to buck converters is that if they fail, they tend to supply the full input voltage to the end device, which can be very bad, depending on how the electronics are designed.  A boost converter doesn't have the same issue, since it would either fail or just output 12VDC.  I'm currently using 3 small buck converters and I've built added overvoltage protection circuits (called a crowbar) to each of them, however, it was a fairly complicated process to do.  Some people risk using buck converters without overvoltage protection or double them up in series to tolerate a single failure.  You also might be able to find 12V versions of your current gear, for example, here's a 12VDC powered USB 3.0 hub you could power directly off of your battery.

-Vince

--

Mount: ES PMC-8 EXOS2-GT

Scopes: BRESSER 208mm f/3.9 Newt + ES HR Coma Corrector, Celestron C90 Mak, generic 50/191mm guide scope

Cameras:  Canon EOS RP, T7C (ZWO ASI120MC clone)
Misc: 2" Optolong L-eNhance filter, 2" Optolong UHC filter, Raspberry PI 4

Software: INDI + Kstars + EKOS, DeepSkyStacker, GIMP, Lightroom, Photoshop, SIRIL

On Jul 18, 2020, at 11:00 AM, Mark Christensen <mjcw500@...> wrote:

Jeff,

One thing that is biting you, I am sure, is the focal length of the 8 inch SCT. That is 2000mm compared to (assuming your APO is f/7) 570mm for your APO. That means the imaging results are nearly 4 times more sensitive to the mounts capabilities, irrespective of weight, which I kind of doubt is the issue.  It also means your exposures, because the SCT is an f/10, have to be twice as long, increasing the window of time in which you are vulnerable to problems in the system, atmosphere, you name it.

So I wouldn't just blame the weight capacity of the mount. 2000mm focal length is pushing it for a mount of this class. Some people make it work but most end up frustrated.
It's why people buy things like the Losmandy G11.

Hope you've been imaging the comet with camera lenses and your APO. With a short focal length telephoto with a fast lens all you need is a tripod, even something as short as 85 or 135mm focal length can produce nice pictures of it. And the speed of that type of lens (f/1.4 to f/2.8 typically) make for short exposures.

With the 8 inch SCT all you'll get is the nucleus.

Sincerely,

Mark Christensen