First of my December Images IC443The JellyfishPosted By Dave Erickson |
Wow Floyd that is really nice! Dave
Posts Made By: Dave Erickson
January 7, 2014 05:17 AM
Forum:
CCD Imaging and Processing/Deep Sky
January 15, 2014 09:47 AM
Forum:
Equipment Talk
battery packsPosted By Dave Erickson |
Hi Brian,
All good advice. Prior to the remote setup I'd go to the field for several days and power was always an issue. I drained the car battery in the field more than once and needed to do something different. Here is an image of a DIY 3-bank setup with charger power-supply and both "visual" voltage monitoring and "computer" voltage and current monitoring. It is very heavy 75pounds, used AGM deep cycle sealed batteries, but worked. Three banks with 21 amp hours each. One bank for cameras, one for computers, and the third for mount and focus.
Best,
Dave
All good advice. Prior to the remote setup I'd go to the field for several days and power was always an issue. I drained the car battery in the field more than once and needed to do something different. Here is an image of a DIY 3-bank setup with charger power-supply and both "visual" voltage monitoring and "computer" voltage and current monitoring. It is very heavy 75pounds, used AGM deep cycle sealed batteries, but worked. Three banks with 21 amp hours each. One bank for cameras, one for computers, and the third for mount and focus.
Best,
Dave
January 15, 2014 10:17 AM
Forum:
CCD Imaging and Processing/Deep Sky
Pacman nebulaPosted By Dave Erickson |
Wow, beautiful...
January 17, 2014 12:06 AM
Forum:
CCD Imaging and Processing/Deep Sky
M51 Luminance dataPosted By Dave Erickson |
Hi Russ,
That is a very nice image!
Regards,
Dave
That is a very nice image!
Regards,
Dave
February 8, 2014 07:21 PM
Forum:
Home Observatories
New Observatory SitePosted By Dave Erickson |
Hi Russ,
Looks like a very good site with a very good horizon. If I am correct on the approximate location sky is a Bortle 4 with very good southern and eastern skies. How is the southern and eastern horizon? Have you observed from there long? Nice to have utilities near by and good internet as well. Please keep us posted on your progress.
Dave
Looks like a very good site with a very good horizon. If I am correct on the approximate location sky is a Bortle 4 with very good southern and eastern skies. How is the southern and eastern horizon? Have you observed from there long? Nice to have utilities near by and good internet as well. Please keep us posted on your progress.
Dave
March 24, 2014 01:20 AM
Forum:
Telescope Making
Mystery Quartz Flat or BlankPosted By Dave Erickson |
quick way is to measure its density fused quartz and fused silica have a density of 2.2 gm/cc or (137.4)(lb/ft3). Measure the diameter and thickness calculate the radius pi*r^2*thickness is the volume measure its mass divide the mass by the volume and you get density. Looks polished on both sides you can also measure the refractive index by measuring the thickness then measuring the optical path using a traveling microscope. Optical path length =refractive index*Thickness... Fused silica should have an index of about 1.46 at 500nm... I have used both methods many times to sort out mixed materials...
March 27, 2014 03:50 AM
Forum:
CCD Imaging and Processing/Deep Sky
NGC1763Posted By Dave Erickson |
Roland,
Some great astro imaging, thats a beautiful optical system...
Dave
Some great astro imaging, thats a beautiful optical system...
Dave
March 30, 2014 03:12 AM
Forum:
CCD Imaging and Processing/Deep Sky
NGC 1999Posted By Dave Erickson |
Hi Enrico,
That is very nicely done! And in addition to Roland's a perfect start to the 2014 season...
Best,
Dave
That is very nicely done! And in addition to Roland's a perfect start to the 2014 season...
Best,
Dave
March 30, 2014 03:35 AM
Forum:
Telescope Making
open OTA for refractors???Posted By Dave Erickson |
Hi John,
With all your experience, I think you know the answer very well...Aside form being minimalist is there some compelling reason for an open tube, so many disadvantages strength and associated flexure, even a truss structure with long throw and small base has flexure issues, air currents dirt and dust.. 180 is not that big I'd go with a carbon tube if you are concerned with weight, an aluminum tube will be a lot simpler and less expensive. These are all things you know well from your years building and rebuilding... No irreverence intended just an affirmation of what you already know...
OH and building a refractor of that size and speed is one #$%% of an accomplishment, hats off to you...
Best regards,
Dave
With all your experience, I think you know the answer very well...Aside form being minimalist is there some compelling reason for an open tube, so many disadvantages strength and associated flexure, even a truss structure with long throw and small base has flexure issues, air currents dirt and dust.. 180 is not that big I'd go with a carbon tube if you are concerned with weight, an aluminum tube will be a lot simpler and less expensive. These are all things you know well from your years building and rebuilding... No irreverence intended just an affirmation of what you already know...
OH and building a refractor of that size and speed is one #$%% of an accomplishment, hats off to you...
Best regards,
Dave
April 15, 2014 07:47 AM
Forum:
After Dark
The Rusty MoonPosted By Dave Erickson |
Hi Andy,
Yes both from Huntington Beach Ca and the remote observatory in the southern Sierra Nevadas Regards,
Dave
Yes both from Huntington Beach Ca and the remote observatory in the southern Sierra Nevadas Regards,
Dave
Funding Member
