RE: [APML] Help! Advice on collimating a C14

Hi Bill,

Thanks for your 2 cents! I did begin to wonder about the diagonal last night. I realized that all my observing (and collimating) have been while using the 2" mirror diagonal that came with the C14. What if there is something wrong with the diagonal? It may be wishful thinking that the solution is that obvious, but who knows?

Yesterday I looked into shipping the C14 back to Celestron in Torrance from here in DC, just in case that's necessary. What I discovered is that this solution would definitely have to be the very last resort, and maybe not even then. Three-day air would cost about $700 round trip (Celestron makes you pay both ways). If I settled for ground, I could get by for about $250, but I understand that ground shipping is rougher than air service. The problem with the C14 is that you can't add too much thickness of padding around it, because you bump into the size constraints for shipping by FedEx, UPS, etc., and then you have to go freight, at a two-way cost of about $2400!! Yikes, I could buy a used (and properly collimated) C14 for not much more than that.

Anyway, thanks again. I plan to incorporate everyone's suggestions as soon as I am back at the 'scope and have a clear night.

Clear skies,

Andy

P.S. Yes, there are a lot of "astrohams"! I was turned on to ham radio back in my teens by adult members of the astronomy club I belonged to who were also hams. Both hobbies have been with me for 25 years since then.

-----Original Message-----
From: astro-photo-bounces@seds.org [mailto:astro-photo-bounces@seds.org]On Behalf Of Bill Logan
Sent: Tuesday, November 30, 2004 8:25 AM
To: astro-photo@seds.org
Subject: [APML] Help! Advice on collimating a C14

Andy,

Allow me to add my two-cents worth. I own a Celestar 8 and a NexStar11GPS SCTs. The NexStar11GPS has Bob's Knobs and is permanently pier mounted. Rarely does it need collimating. In addition to all the other advice that have gotten, you may want to check your diagonal. Celestron's diagonals are not the best. I had a diagonal that was so bad that I could see the light baffle inside the SCT. I went so far as to return the Celestar 8 back to the factory for alignment only to find that I could still see the baffle when it returned. I could not figure out why I could have perfect collimation and see the baffle.

By the way, it was very expensive to ship my Celestar 8 back to California via UPS (I live in Arizona!). How does $150 sound? It cost $150 for the repair and shipping back. If you don't have a shipping container for the C-14, I would suggest taking it a mail packing place and "watch" them pack it. Also be sure to insure the scope. When my Celestar 8 came back, it was damaged so bad by UPS, that it had to be returned again for repair at Celestron's expense. If you live in "4" land, I would imagine the shipping charges for a C-14 to Torrance, CA is will be somewhat higher.

My suggestion for good collimation is to start with low power eyepieces. I start with a 40 mm and my final collimation is done with a 6 mm eyepiece with a 2X Barlow. Check to see that you have good collimation on both sides of focus. If it's not, send it back to Celestron. The focuser may be worn out making the primary mirror so loose that it won't collimate.

Well, that's my two-cents worth. Hope it helps. I see that you are also a ham. It amazes me how many amateur astronomers are also hams. There must be a connection. Hi hi!

Best 73

Clear and dark skies,
Bill Logan, WB9SAT
U. S. Army Retired
President (interim) White Mountains Astronomy Club
Logan Observatory: http://www.geocities.com/wb9sat/index.html
Logan Observatory Sky Clock: http://cleardarksky.com/c/LgnObAZkey.html?1
White Mountains Astronomy Club: http://geocities.com/wb9sat/WMAC.html