Hello everyone, I just upgraded to the Orion XT 12 and I'm loving that huge aperture! One question, though; is anyone in or near the Vista / San Diego CA area?...
You can find a local club at <http://skyandtelescope.com/resources/organizations/> They should be able to tell you where the good sites are. -John ... ...
We have an Un club of TAC enthusiasts located in the San Diego area. I don't know how often they get together. We all get together a couple of times a year at...
Oh yes, I like the Shingletownn venue more than any other star party I go to. I just wish it got dark a little earlier. But the showers, the organization of...
Andreas Sheriff wrote; One question, though; is anyone in or near the Vista / San Diego CA area? If so, where do you observe that's safe and dark? I've been ...
Hello All, I hope that a 12.5" scope qualfies as "big" :-) Well, I finally got some unhurried free time this weekend, and of course, it was time for ...
Gregory, Most scopes will have a total system "flex". It's very hard to prevent. Some OTA's actually bend a little bit, others have mirror cells that tend to...
... A few questions: Is the observed deviation (from the primary mirror center spot) +/- 1.8mm, or +3.5mm -0.0mm? What's the focal ratio of the scope? What's...
Gregory Some movement or flex when moving in the alt axis would be the norm for most truss scopes, however the side to side movement is mysterious. I think I...
I've had my new (pre-owned) Coulter 17.5" Dob out a couple different nights and I've got a question for you experienced viewers. Being this is my first large...
Richard, ... Here are some things to consider: 1. If the scope is in its original closed sonotube, you may have difficulty with the mirror holding heat. This...
Thanks so much for responding! This paticular scope is a very nicely built Truss design with break-away bars and all. Everything is hand built. However, the...
... I've heard widely varying claims for the quality of Coulter mirrors. These were made in the early days of dobs, when the emphasis was on big aperture ...
Hello Vic and all, ... I think the answer is the latter, i.e., +3.5mm -0.0mm. There is a very smooth transition of the beam spot as the scope is moved from its...
... At f/5, without a Paracorr, the allowable error (for a 12.5 inch aperture) is about 6mm. With a Paracorr that tolerance is reduced to 1mm. ... Is the...
I once had this problem. The reason was, that some of the furniture pads upon which the mirror was resting were new and the others were old. The new ones would...
Sorry, this can't be the problem in this case. Jan http://home.wanadoo.nl/jhm.vangastel/Astronomy/ ... From: "Jan van Gastel" <jhm.vangastel@...> To:...
... I can't tell from the pictures- are the dark spots dirt, or spots where the aluminum has come off? ... Is that a real floatation cell? It looks like the...
Those are spots on the mirror that aluminum as come off. If you hold the mirror up to the light you can see through the glass. I'll have to double check on the...
Hello again all, ... I think the answer is "in-between", as it is angled slightly upward from horizontal (about 15 to 20 degrees or so). Though it would...
... Uh, what the heck does that mean? I'm not concerned with the triangles. Each "floats" on a single support point. ... Check to see if the six points are...
... Interesting, as there must be some freedom of motion or tortioning for the observed beam deflection... ... I'm not sure. This is a LightBridge design,...
... Not from his earlier description it isn't: "My 12.5" truss Dob has a 3-vane ProtoStar spider with metal secondary shroud for the 2.6" secondary,...
... Thanks John, I was trying to read back through the previous posts to verify what kind of scope we were discussing (in this discussion group!) I'm still...
Hey guys, Remember when I was complaining that I couldn't get the Intelliscope on my Orion SkyQuest XT12 to work? I think I figured out why. Looking at Starry...
The back of the 17.5" Dob, room for a fan for sure http://scopetrader.com/Photography/ViewPhoto.asp?Photo=128 And here is a close up of one of the arms on the...
From the original pictures, you need to recoat the mirror. It has major flakes and probably many many pinholes. I had a (not as bad but) similar situation of...
