moynihan
Carpal Tunnel
Reged: 07/22/03
Posts: 1517
Loc: Wisconsin
|
|
Hi,
I have an older c8 ota with shot secondary coatings in storage. It is a mid-80's model, but optics were good. In its day, on very steady nights Jupiter looked like a mini-hubble shot. I have been toying with the following idea:
Getting the secondary re-coated,
Getting it cleaned/realigned,
Having the primary mirror "fixed" at its optimum distance, and having one of dem dar crayford/feather touch etc, type focusers put on.
Question: Does anyone know of a person/place that would do all that?
thanks for any info you might share.
jay
--------------------
"Gosh, you've... really got some nice toys here"
Dual mount/ambient temperature Hominid Widefield Photon Collectors®
Pleistocene™ ˝ watt Wetware Integration Unit.
entia non sunt multiplicanda praeter necessitatem
|
Anonymous
Unregistered
|
|
Hi Jay,
Ive got a C8 that I was considering removing the corrector plate and adding multiple baffles inside the OTA myself if/when it ever gets dusty again inside but, its quite a project to remove/replace the corrector so I havent touched it. I did open up the corrector once to clean the primary and the inside of the corrector and replaced it exactly back the way it was and its working perfect. I heard that if you do remove the secondary tho that you want to measure and replace it back in the same spot than collimate precisely. Have you ever done this procedure yet? Its not hard really just need a very dust free clean area to do it all in. Now that mine is all clean and collimated I dont have the heart to open it again, I may just buy a second OTA to experiment on eventually. I would imagine any of the mirror coating businesses out there would gladly recoat your secondary and being so small it probably only costs $ 30 or less from what ive read. Dave
|
rboe
Numbfinger
Reged: 03/16/02
Posts: 39716
Loc: Phx, AZ
|
|
In the following link this gentleman tore down a NS11 and redid it. Many aspects of the project will apply to your scope.
The guy has a very slick site with just plane wonderful pictures and graphics. He's a pro. A great read in any event.
http://www.rothritter.com/website/index.html
--------------------
Ron
NS11GPS
Pronto
16" dob
15X70 Obies
|
Anonymous
Unregistered
|
|
Thanks rboe,
always looking for some new reading, maybe Ill get the nerve(guts)to redo mine one last time! Dave
|
moynihan
Carpal Tunnel
Reged: 07/22/03
Posts: 1517
Loc: Wisconsin
|
|
The only time i opened mine up, took off the corrector, was to seen what was wrong with the secondary. That was how i discovered the coating on it had gone bad.
--------------------
"Gosh, you've... really got some nice toys here"
Dual mount/ambient temperature Hominid Widefield Photon Collectors®
Pleistocene™ ˝ watt Wetware Integration Unit.
entia non sunt multiplicanda praeter necessitatem
|
jrcrilly
Refractor wienie again
Reged: 04/30/03
Posts: 22464
Loc: NE Ohio
|
|
If it's mid-eighties the corrector may or may not have Starbright coatings. I know you said this one had good optics but these days it's much less of a crap shoot; any late-model C8 will probably be as good as the best examples from back then and will have the better coatings as well (unless yours has 'em).
It becomes a question of economics. A late-model, perfect C8 can be found for $500 or so. Yours in its present condition would bring at least $300. For the cost difference a newer one might make a lot of sense.
--------------------
John C
Urban Observatory
Tele Vue Pronto
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 152ED F/9 "APO"
152mm F/10 achromat
Tak CN-212 8" F/12 classical Cass/ F/4 Newt
Teeter 20" F/3.8 truss Newt w/ServoCat
LXD750, EM-200, CI-700
ST-10XME
|
moynihan
Carpal Tunnel
Reged: 07/22/03
Posts: 1517
Loc: Wisconsin
|
|
Yah...It had "starbright" coating. It was in fact when they first came out with an enhanced coating (silver compound of some sort), and only on the secondary. 
--------------------
"Gosh, you've... really got some nice toys here"
Dual mount/ambient temperature Hominid Widefield Photon Collectors®
Pleistocene™ ˝ watt Wetware Integration Unit.
entia non sunt multiplicanda praeter necessitatem
|
jrcrilly
Refractor wienie again
Reged: 04/30/03
Posts: 22464
Loc: NE Ohio
|
|
That does make it sound more like it's worth saving. Could be worse; Meade's MCSOG upgrade coatings of that era were on both mirrors and they didn't age well either. Dunno why they thought silver wouldn't oxidize...
--------------------
John C
Urban Observatory
Tele Vue Pronto
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 152ED F/9 "APO"
152mm F/10 achromat
Tak CN-212 8" F/12 classical Cass/ F/4 Newt
Teeter 20" F/3.8 truss Newt w/ServoCat
LXD750, EM-200, CI-700
ST-10XME
|
Anonymous
Unregistered
|
|
Starbright coatings are the anti-reflective coatings on the corrector not the mirrors if im correct. You just need to remove & send the little secondary off to be recoated and then put it all back together. After reading the link provided from rboe, dosent sound like flocking the OTA is worth the trouble while its open tho. Guess Ill leave mine as is....Dave
|
jrcrilly
Refractor wienie again
Reged: 04/30/03
Posts: 22464
Loc: NE Ohio
|
|
Hi, Dave.
That's correct. What he's referring to, though, is that when Starbright was an option they aparently sometimes included upgraded mirror coatings as well - and used silver in 'em. Meade did it, too - avoid MCSOG optical tubes from the 80's (the S means silver).
--------------------
John C
Urban Observatory
Tele Vue Pronto
A&M/Astreya 76mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Tak FSQ-106N F/5 APO
Meade 152ED F/9 "APO"
152mm F/10 achromat
Tak CN-212 8" F/12 classical Cass/ F/4 Newt
Teeter 20" F/3.8 truss Newt w/ServoCat
LXD750, EM-200, CI-700
ST-10XME
|
moynihan
Carpal Tunnel
Reged: 07/22/03
Posts: 1517
Loc: Wisconsin
|
|
hmmm...
I looked at that c11 modification on that site mentioned. Being in possession of ten thumbs, I could not go that far myself. But getting the secondary re-done, and gettin on of dem neat focusers... 
Then the question of what to mount it on. Its old mount is serving other duty now. 
--------------------
"Gosh, you've... really got some nice toys here"
Dual mount/ambient temperature Hominid Widefield Photon Collectors®
Pleistocene™ ˝ watt Wetware Integration Unit.
entia non sunt multiplicanda praeter necessitatem
|
rboe
Numbfinger
Reged: 03/16/02
Posts: 39716
Loc: Phx, AZ
|
|
You don't need special coatings like Starbright on the secondary - it's a reflector. Enhanced reflective coatings as they use on the fancy TV units would be nice - but Starbright coatings are for the corrector plate to increase light transmission. But it should be an easy matter to fix up. How does the primary look? May be a good time to recoat it too.
In case you don't have their link all ready....
http://www.spectrum-coatings.com/index.htm
--------------------
Ron
NS11GPS
Pronto
16" dob
15X70 Obies
|
moynihan
Carpal Tunnel
Reged: 07/22/03
Posts: 1517
Loc: Wisconsin
|
|
The primary is really clean and clear.
--------------------
"Gosh, you've... really got some nice toys here"
Dual mount/ambient temperature Hominid Widefield Photon Collectors®
Pleistocene™ ˝ watt Wetware Integration Unit.
entia non sunt multiplicanda praeter necessitatem
|
Anonymous
Unregistered
|
|
Ah, I see what you are saying there. Sounds like a simple recoat and he is in business if the primary is ok. All the older scopes make me very wary because of the coatings issues. Better technologies today for all lens, mirrors coatings. Dave
|
moynihan
Carpal Tunnel
Reged: 07/22/03
Posts: 1517
Loc: Wisconsin
|
|
thanks for the coating company link!
--------------------
"Gosh, you've... really got some nice toys here"
Dual mount/ambient temperature Hominid Widefield Photon Collectors®
Pleistocene™ ˝ watt Wetware Integration Unit.
entia non sunt multiplicanda praeter necessitatem
|
rboe
Numbfinger
Reged: 03/16/02
Posts: 39716
Loc: Phx, AZ
|
|
Moynihan;
I'm confused now. A primary should not be clear: It's the main mirror. I would hate to be spouting off advise when we're all talking about different parts!
But it does sound like a neat project that may cost a bit more than practical. But Astronomers work 6 to 8 years in school and end up with a night job! Or you could just clean it up and put it up on display. Then buy yourself a newer model. We all need a good excuse to buy another scope! 
--------------------
Ron
NS11GPS
Pronto
16" dob
15X70 Obies
|
moynihan
Carpal Tunnel
Reged: 07/22/03
Posts: 1517
Loc: Wisconsin
|
|
Sorry, By clear (the primary is clear) i did mean clean, no marks. I did mean the primary mirror, not the correcter.
--------------------
"Gosh, you've... really got some nice toys here"
Dual mount/ambient temperature Hominid Widefield Photon Collectors®
Pleistocene™ ˝ watt Wetware Integration Unit.
entia non sunt multiplicanda praeter necessitatem
|
rboe
Numbfinger
Reged: 03/16/02
Posts: 39716
Loc: Phx, AZ
|
|
Whew! I'm still working with a small fever and easily confused. Thanks for clearing that up.
--------------------
Ron
NS11GPS
Pronto
16" dob
15X70 Obies
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
