I have a Celestron Cometron Jr. It's a 125mm f8 Jones/Bird-type Catadiotric. The tube is 18.5" long. The optics seem to be in great shape. The 1.25" R&P focuser, also in great shape, has a set screw in the body, along with a thread-in 15/8" extender. I assume these are for photog? There's a dovetail finder mount, but no finder. It has the front tube cover.
There are surface rust blotches on the metal tube, mostly under the paint, which probably totals around 3 sq inches covering a 3"x14" section. A previous owner sanded a small section just enough to dull the gloss on the paint. The rest of it is perfect.
Included is the original Instructions Booklet, a Cometron catalog, a 1981 Celestron General Catalog, and another undated Celestron catalog without a cover.
I also have Celestron's very nice 15"x22" poster re. the history and coming (1986) of Haley's comet, including a month-by-month program from Oct 95-May 96. I may keep this one.
I am going to sell the scope and literature, but really have no idea what it's worth, so any help would be appreciated.
Thanks,
Peterson
Value of Cometron Jr.
Started by
Guest_**DONOTDELETE**_*
, Dec 13 2006 08:21 PM
13 replies to this topic
#2
trainsktg
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Fly Me to the Moon
Posted 14 December 2006 - 12:03 AM
Hmm, I'd like to help, but this is a new one on me. I expected this thread to be one on a Cometron refractor. Can't wait to see a...picture(? 
)
Keith
)Keith
#3
Clive Gibbons
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Mostly Harmless
Posted 14 December 2006 - 09:02 AM
Hi Peterson.
I recall those scopes, as we used to sell them in our shop back in the early to mid '80s.
I don't think they have significant residual value today and there aren't many (any?) folks who'd consider them collectible.
As such, they probably wouldn't sell for any more than a used 5" reflector of recent vintage. Probably a bit less, considering the slight rust damage to the tube.
I'd suggest somewhere in the $100 to $150 range, if there's no mounting or tripod included.
I recall those scopes, as we used to sell them in our shop back in the early to mid '80s.
I don't think they have significant residual value today and there aren't many (any?) folks who'd consider them collectible.
As such, they probably wouldn't sell for any more than a used 5" reflector of recent vintage. Probably a bit less, considering the slight rust damage to the tube.
I'd suggest somewhere in the $100 to $150 range, if there's no mounting or tripod included.
#4
Jon Isaacs
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ISS
Posted 14 December 2006 - 12:01 PM
Hi:
It is tough to put a value on this scope. I had one and it was the scope that really turned me into a starhopper. Mechanically it was quite nice but optically it was subpar, no match the Orion Space Probe 130ST which is just a bit longer at 24 inches. I agree with Clive that there is little collectibility to these, I would use the SP-130 as a reference point and then adjust for the optics. I paid $85 on AM for the SP130ST OTA with rings and a 2 inch focuser.
I also have to say that I would want to discuss the optics with a potential buyer before selling this scope because as I said, IME they were just not very good, I never did get it to split Castor cleanly, something even my "Fifty Dollars at Walmart" 60mm Meade could do.
I had some memorable times with this scope none the less...
On a lighter note, there are some well known observers who have used this scope, here is one the S.A.A. regulars "monkeying around" with the Cometron Jr.
http://homepage.ntlw...21.htm#Monkulas
Best wishes
Jon
It is tough to put a value on this scope. I had one and it was the scope that really turned me into a starhopper. Mechanically it was quite nice but optically it was subpar, no match the Orion Space Probe 130ST which is just a bit longer at 24 inches. I agree with Clive that there is little collectibility to these, I would use the SP-130 as a reference point and then adjust for the optics. I paid $85 on AM for the SP130ST OTA with rings and a 2 inch focuser.
I also have to say that I would want to discuss the optics with a potential buyer before selling this scope because as I said, IME they were just not very good, I never did get it to split Castor cleanly, something even my "Fifty Dollars at Walmart" 60mm Meade could do.
I had some memorable times with this scope none the less...
On a lighter note, there are some well known observers who have used this scope, here is one the S.A.A. regulars "monkeying around" with the Cometron Jr.
http://homepage.ntlw...21.htm#Monkulas
Best wishes
Jon
#5
GeneDiG
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Viking 1
Posted 14 December 2006 - 03:56 PM
I think the OTA is the same as a Tasco 8V. Telescope Bluebook listed the 8V as the only collectible Tasco. However, I too have heard the optics train has issues.
I do believe that it has a spherical mirror ground to a faster f-ratio. I wonder if the 'scope could be made into a fast scope by removing the the built in barlow and flexing the mirror to a parabola. Anyway, it sounds like a fun project ' scope to tinker with and tweak to maximum performance without having to worry about collectible value.
I do believe that it has a spherical mirror ground to a faster f-ratio. I wonder if the 'scope could be made into a fast scope by removing the the built in barlow and flexing the mirror to a parabola. Anyway, it sounds like a fun project ' scope to tinker with and tweak to maximum performance without having to worry about collectible value.
#6
Jon Isaacs
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Posted 14 December 2006 - 07:25 PM
I think the OTA is the same as a Tasco 8V. Telescope Bluebook listed the 8V as the only collectible Tasco. However, I too have heard the optics train has issues.
I do believe that it has a spherical mirror ground to a faster f-ratio. I wonder if the 'scope could be made into a fast scope by removing the the built in barlow and flexing the mirror to a parabola. Anyway, it sounds like a fun project ' scope to tinker with and tweak to maximum performance without having to worry about collectible value.
-------
I don't know about the Tasco 8-V. Does it have a 1.25 inch focuser with a three rod spider, an optical window, no collimation on the primary and the corrector/barlow that mounts to the secondary holder and sits between the secondary and the primary??
I think flexing the mirror is out of the question without moving the primary mirror. I tried removing the corrector with mine and it would not come to focus. Also, I believe the primary is about F/4 so that would take some real flexing.
Jon
I do believe that it has a spherical mirror ground to a faster f-ratio. I wonder if the 'scope could be made into a fast scope by removing the the built in barlow and flexing the mirror to a parabola. Anyway, it sounds like a fun project ' scope to tinker with and tweak to maximum performance without having to worry about collectible value.
-------
I don't know about the Tasco 8-V. Does it have a 1.25 inch focuser with a three rod spider, an optical window, no collimation on the primary and the corrector/barlow that mounts to the secondary holder and sits between the secondary and the primary??
I think flexing the mirror is out of the question without moving the primary mirror. I tried removing the corrector with mine and it would not come to focus. Also, I believe the primary is about F/4 so that would take some real flexing.
Jon
#7
GeneDiG
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Posted 14 December 2006 - 08:28 PM
I don't know about the Tasco 8-V. Does it have a 1.25 inch focuser with a three rod spider, an optical window, no collimation on the primary and the corrector/barlow that mounts to the secondary holder and sits between the secondary and the primary??
Jon
I have not seen an 8V in person. From what I can gather from photos and from A-mart, with the exception of the 1.25 focuser, yes it does have the same specifications that you have called out. There's actually one on that auction site by the bay:
Really big link
Gene
#8
Guest_**DONOTDELETE**_*
Guest_**DONOTDELETE**_*
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topic starter
Posted 14 December 2006 - 09:44 PM
I can tell you that the tubes (except color) look the same. The finder dovetail looks the same & is the same place. The side view of the front tube cover looks the same. The two screws shown, one for the primary & one for the front tube ring line up the same.
The red one is missing the thumb-style screw for secondary adjustment. The focuser is different. The Cometron label says "Made for Celestron in Japan"
Peterson
The red one is missing the thumb-style screw for secondary adjustment. The focuser is different. The Cometron label says "Made for Celestron in Japan"
Peterson
#9
Steve_M_M
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Soyuz
Posted 14 December 2006 - 10:16 PM
And here is one of those Cometron Jrs. that went for $100.
http://cgi.ebay.com/...13844&rd=1&rd=1
Steve
http://cgi.ebay.com/...13844&rd=1&rd=1
Steve
#10
Jon Isaacs
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ISS
Posted 14 December 2006 - 10:19 PM
The Tasco 8-V does look the same to me except for the focuser. The mount looks to Vixen Polaris mount which adds some real value. According to one website the Tasco 8-V was made by Vixen, I figured the Cometron Jr. was a Vixen product. The mount for my Cometron Jr. was an odd alt-az mount with a short pier and a counterweight, nicely made and compact but I always used the scope on a tripod.
Ebay may be the place for this scope.
jon
Ebay may be the place for this scope.
jon
#11
Jon Isaacs
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ISS
Posted 14 December 2006 - 11:11 PM
>>>And here is one of those Cometron Jrs. that went for $100.
http://cgi.ebay.com/...13844&rd=1&rd=1
Steve
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That one looks just like the one I had down to every last detail, stickers and all, even the quite decent 25mm Kellner.
I think the description of the optics was reasonable: shows Jupiter's moons, Saturn's Rings..
But IMHO, a 5 inch Scope should show not only Jupiter's moons but Shadow transits, not only Saturns rings but Cassini's division as well.
Jon
http://cgi.ebay.com/...13844&rd=1&rd=1
Steve
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That one looks just like the one I had down to every last detail, stickers and all, even the quite decent 25mm Kellner.
I think the description of the optics was reasonable: shows Jupiter's moons, Saturn's Rings..
But IMHO, a 5 inch Scope should show not only Jupiter's moons but Shadow transits, not only Saturns rings but Cassini's division as well.
Jon
#12
Guest_**DONOTDELETE**_*
Guest_**DONOTDELETE**_*
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topic starter
Posted 15 December 2006 - 08:56 PM
Just wanted to thank everyone for their contributions. I'm thinkin' it's worth around 65.00. I don't care for ebay, so I'll list it in Shop & Swap, and if no CN guys want it, I'll try Amart.
Peterson
Peterson
#13
Jon Isaacs
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ISS
Posted 15 December 2006 - 10:36 PM
Probably more than reasonable even if it just were for the parts. As I remember it, the focuser is quite nice.
Jon
Jon
#14
RogerRZ
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Whatta you lookin' at?
Posted 17 December 2006 - 09:33 AM
The Tasco 8V comes with a .965" focuser. The local high school here has one, and like Jon said, it has a qood quality Vixen Polaris mount. I never really looked through it, as they have lost all the eyepieces for it, and I don't have anything in the .965 size...
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