SCT Focuser talk,Posted By James McSheehy |
Greg Harper said:
I have an old 11:1 focuser from a refractor.
Name of the manufacturer?
Posts Made By: James McSheehy
March 5, 2011 11:36 PM
Forum:
Equipment Talk
Name of the manufacturer?
March 17, 2011 03:29 AM
Forum:
Equipment Talk
Arizona Sky VillagePosted By James McSheehy |
I visited the area last month and saw both ASV and the newer dark-sky developments (Rancho Hidalgo and Granite Gap) across the border in NM. The area is in a grey/black zone on the Bortle scale, and Sky brightness (using a SQM-L) measured 21.89 -- about as dark as anyplace in the continental U.S. The climate is high desert (elev. 4500 ft.), so the air is also dry and transparent.
ASV still has a couple of building lots for sale, but as others noted, several owners offer rentals for visitors and that is the only practical way to observe in the otherwise closed community. Over in NM, numerous observatories are under construction along with permanent residences and some triplex time-share rentals. Unlike the ASV, lots for the houses are separated from the area reserved for observatories and RV pads. This makes sense as Granite Gap and Rancho Hidalgo are billed as more than just a place for astronomy and the developer also expects to draw birders, rock hounds, model rocketry enthusiasts, and other eco-tourists into the mix.
ASV still has a couple of building lots for sale, but as others noted, several owners offer rentals for visitors and that is the only practical way to observe in the otherwise closed community. Over in NM, numerous observatories are under construction along with permanent residences and some triplex time-share rentals. Unlike the ASV, lots for the houses are separated from the area reserved for observatories and RV pads. This makes sense as Granite Gap and Rancho Hidalgo are billed as more than just a place for astronomy and the developer also expects to draw birders, rock hounds, model rocketry enthusiasts, and other eco-tourists into the mix.
March 24, 2011 02:53 AM
Forum:
CCD Imaging and Processing/Solar System
Camera OptionsPosted By James McSheehy |
The Point Grey cameras offer FireWire 800 interfaces. Most laptops don't have separate busses for the USB ports, and plugging in a high bandwidth device like a camera can limit the performance of the remaining USB ports. FW is usually on its own DMA bus and it might allow improved frame rates. Unlike FW and USB, GigE requires a separate connection for power.
April 2, 2011 02:22 PM
Forum:
Off Topic Discussions
This would be a great sign for AstromartPosted By James McSheehy |
Nice catch. It shows how "graphics" have replaced art in much of our day-day. The world is poorer for it.
April 3, 2011 02:28 PM
Forum:
AstroMart FAQ
Selling softwarePosted By James McSheehy |
What does the EULA (end user license) say? If SB considers your new subscription as an extension of the original license, then they probable won't let the new owner upgrade. I read on the SB support forum that the license for software bundled with Paramounts is keyed to the hardware.
April 5, 2011 02:19 AM
Forum:
Refractors
TEC to stop production of TEC160ED?Posted By James McSheehy |
TEC still offers the fluorite version of the 160.
April 7, 2011 02:52 PM
Forum:
Digital SLR AstroPhotography
CNC SupplyPosted By James McSheehy |
I agree, my two orders over the past year were handled well and the adapters were good quality and fit perfectly. The internal black anodizing on the parts was a little too reflective for my taste, but a bit of flat-black Krylon took care of that.
April 28, 2011 02:56 PM
Forum:
Equipment Talk
Mounting Intes Alter 703 mak on Nexstar8-GPS fork?Posted By James McSheehy |
The Mak weighs about 17 pounds so the one-armed bandit should be fine for visual use. Don't go crazy and try to add a big finder, piggy back SLR, and a heavy CCD and you'll be OK. Baader Planetarium sells a nice dovetail adapter plate for the Nexstar mounts.
I use this setup with a TV-85 and it's important to get the tension on the elevation clutch set so there is no slippage when slewing a heavy OTA. The "clutch" is a cork disk and tension is set by tightening or loosening the hex nut at the center of the adapter plate. Baader has good instructions for this adjustment in their kit.
I use this setup with a TV-85 and it's important to get the tension on the elevation clutch set so there is no slippage when slewing a heavy OTA. The "clutch" is a cork disk and tension is set by tightening or loosening the hex nut at the center of the adapter plate. Baader has good instructions for this adjustment in their kit.
May 1, 2011 04:02 PM
Forum:
Reflectors
Help needed with Cassegrain assemblyPosted By James McSheehy |
The hyperbolic secondary has two foci. One should coincide with the focal point of the primary, and the other should be the focal plane of the image behind the primary. If you know or can measure the radius of curvature of the secondary mirror, then the first foci is located at approximately 1/2 the ROC behind the secondary.
If the mirrors were an ATM project, these given focal lengths and multipliers probably have a large tolerance, for example the f/4 primary might actually be f/4.2. Don't assume any of the given numbers are correct - verify them. An error of 3 mm in the spacing will shift the focal plane by more than 70 mm. You probably don't want to hear this, but your best bet is to build a horizontal test bench setup from plywood and noodle it out by trial and error.
If the mirrors were an ATM project, these given focal lengths and multipliers probably have a large tolerance, for example the f/4 primary might actually be f/4.2. Don't assume any of the given numbers are correct - verify them. An error of 3 mm in the spacing will shift the focal plane by more than 70 mm. You probably don't want to hear this, but your best bet is to build a horizontal test bench setup from plywood and noodle it out by trial and error.
May 8, 2011 12:52 PM
Forum:
Off Topic Discussions
Mr. ArmstrongPosted By James McSheehy |
Congratulations -- talk about a rare sighting! For many years he was described as a recluse, and some reports even suggested he was mentally ill. Perhaps he's turned a corner.
Funding Member
