Apology to Mark HarryPosted By Walter Hamler |
I called you "Harry" in an earlier post. Oops! Sorry Mark
Posts Made By: Walter Hamler
April 12, 2002 05:20 PM
Forum:
Telescope Making
April 12, 2002 09:13 PM
Forum:
Telescope Making
What do I have here?Posted By Walter Hamler |
Well, I just finished making a mask to check readings on my 10" f/6, and I would like some of you out there to tell me how close I am. Actually, I think I'm darn close, but some of you may have a number crunching program that will tell me. I'm an old geezer and math was a long time ago!
10" mirror, 121.2" RC. I checked at the 32%, 70%, and 95% zones. Readings (avg of 4) are. 0, .025, .101, and .180. My math says I'm only a few thousands away from perfect, if I understand the process.
Anxiously awaiting your responses.
Walt
10" mirror, 121.2" RC. I checked at the 32%, 70%, and 95% zones. Readings (avg of 4) are. 0, .025, .101, and .180. My math says I'm only a few thousands away from perfect, if I understand the process.
Anxiously awaiting your responses.
Walt
April 16, 2002 01:15 AM
Forum:
Telescope Making
Lensless Schmidt camerasPosted By Walter Hamler |
MANY years ago I bought an 8" f/2 spherical mirror and film holder from Coulter Optical in CA. The idea was to make a lensless Schmidt camera by placing a field stop at the RC of about 5" in diameter. That, in conjunction with a curved film holder supported by a spider vane, was supposed to give relatively good astro images on 35mm film or 2" circle cut film. Well, I never actually put it together, and sold the set some time ago. Now, a friend has a 10" f/2.95 spherical primary that he wants to use for the same purpose. He is proposing a 7" aperature but projecting the image out to a camera body via a 3.1" diagonal. I'm leary??? Any knowledgable inputs/experiences out there?
Walt
Walt
April 27, 2002 11:31 PM
Forum:
Lost Contacts and Personal Messages
Tim HoglePosted By Walter Hamler |
Anybody in So. CA know of/wherabouts of Tim Hogle. I last saw him in 1978/79 at the ASTROphoto Conference. He was working JPL at the time.
Walt Hamler
Walt Hamler
May 21, 2002 01:12 AM
Forum:
Deep Sky Observing
Gamma Virginis RevisitedPosted By Walter Hamler |
Tonight was the first clear night since getting my recently completed 10" f/6 back from the coaters. A cold front had just moved through so typically the seeing is horrible for the first day but I had to try. Looked at Jupiter, but being low was greeted by typical mushy appearance due to lower altitude. Looking directly over the roof of my house didn't help either! However, the occasional moments showed the moons as tiny littlt discs at 120x, so I was happy. As it got darker I switched to Castor, but that was too easy. So I turned around to Virgo, found Gamma, and even at 120X, I could tell it was double. Put in the 2.5X and voila!, there they were, two perfect little discs floating in mostly mush. Well, you know what I mean, not perfect discs, but when it momentarily cleared, they looked great. I'm HAPPY!
Walt
Walt
June 1, 2002 01:25 AM
Forum:
Telescope Making
Re: Enlarger lensPosted By Walter Hamler |
In the case of an enlarger lens, the listed f is the focal length, the f/number is the speed, ie f/4.5, so the approximate aperature would be 164/4.5 = 36.4mm. It really wouldn't make a very good telescope, but a useful small finder maybe.
June 2, 2002 09:06 PM
Forum:
Equipment Talk
Feathertouch FocusersPosted By Walter Hamler |
Anyone out there who owns a Feathertouch focuser, can you tell me how the focuser unit attaches to the base? I am considering buying just the basic body and adapting it to the base of a current 2" focuser.
Walt
Walt
June 5, 2002 03:41 PM
Forum:
Telescope Making
Flocking MaterialPosted By Walter Hamler |
I recently purchased a sufficient quantity of the black flocking material from Protostar to put in the tube of my 10" f/6 dob. It is an outstanding product and works as advertised in every way, albeit a little difficult to install in my case. They actually sent me more than I ordered so I had enough to do most of the tube for my 8" f/6 also. Anyway..... Yesterday I was browsing the McMaster-Carr website Http://www.mcmaster.com and found a listing for velvet, self adhesive back, 45" wide. I ordered 3' just to see. It arrived this AM!!!! and it is the same stuff as what Protostar sells. Price is 4.26/ft and works out to about 65% of the cost through Protostar. It also is available in a plain, non-stick backing for even cheaper price.
Walt
Walt
June 11, 2002 08:20 PM
Forum:
Equipment Talk
Drive CorrectorsPosted By Walter Hamler |
Are there any new drive correctors out there for 115vac synchronous motors? I have seen a couple used ones for sale on Astromart that were the old Bradford-West kits, and someone told me that JMI used to make one but no longer.
Otherwise I'm going to have to convert to stepper and don't really want to.
Walt
Otherwise I'm going to have to convert to stepper and don't really want to.
Walt
June 21, 2002 11:56 PM
Forum:
Telescope Making
Moonlite Focuser revisitedPosted By Walter Hamler |
Back in April there were some posts on this brand focuser. After some comparison shopping and looking, I bought one, but got a Black version, as I guess I'm old fashioned!! Anyway, its truly is a very nice unit, and Ron Newman was very helpful and a pleasure to deal with. NOW, please let the clouds depart!!!
Walt
Walt
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