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The vintage Coulters

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#26 JamesDuffey

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Posted 14 September 2021 - 01:35 PM

Not to put too fine a point on it, but it seems to me that buying an Odyssey (used of course) these days is also buying the opportunity to spend more money (a lot more in some cases) on a coma corrector, wide field eyepieces, a convenient focuser (if the original hasn't already been replaced) or a 2 inch focuser if you want wide angle views, a better mirror cell, a secondary spider that can be straight forwardly adjusted, and, quite possibly repairs or tweaks to the mount or at the very least, bigger altitude bearings. Whenever I think about  buying one, I flash back to the picture that someone  posted of a Paracor II and an Ethos in a red Odyssey 13.1 fitted with a much better after market focuser. So, that is $1200 worth of glass in a $300 scope, plus the improved focuser, and I come to my senses that there are probably better, or at least more efficient ways to spend $1500 on a telescope and eyepieces. 

 

I think that most people value the larger Odysseys as a cheap source of largish mirrors and you see a lot of 13.1 inch and 17.5 inch truss scopes that must have started life as an Odyssey.  You see few Odysseys for sale in original and good shape and more than occasionally one that says the mirror has been refigured and mounted in a better cell. That tells me something. You can buy a used "modern" dob for not much more than an Odyssey. 

 

Still, there is a red 8 inch for sale in CO, whose price has been dropping every two weeks....



#27 CHASLX200

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Posted 14 September 2021 - 06:16 PM

After a taste of some very great Newts i would never live with so so views with any kind of scope no matter if it was free.  I just gotta have Tak like images if ya all get my point.


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#28 oldmanastro

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Posted 14 September 2021 - 10:06 PM

Coulter had two versions of the 8". One was an f/4.5 and the other an f/7. I owned the f/7 for more than ten years since 1994. The optics were very good but the tube currents were an issue. After everything cooled down the performance was excellent. It was the telescope that I used to see comet Shoemaker-Levy fragments impact Jupiter. I regret selling it in 2005-6. When I started using it and noticed the tube currents, I called Coulter for solutions and had a conversation with the owner. He was a very nice guy and told me that this could be a problem with the longer tube o the f/7 and the closed mirror mount. There was no solution to cool the interior of the scope faster except by modifying the tube itself.  

In the end I decided to live with it because the performance was so good. I wish Coulter had never disappeared.


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#29 BarabinoSr

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Posted 16 September 2021 - 05:53 PM

Coulter also made  14 1/4 " f/7 mirror sets. I built my first large instrument using the optics purchased from a PAS clubmember in 1982, and the scope was built in 1983 from parts I scrapped up. It was a bit crude and cumbersome to use but I remember the impressive views it showed of Jupiter and Saturn.I also got looks a M51 and the Ring Nebula.Sadly I lost it to the floodwaters of Hurricane Katrina in 2005..However I have another set of the optics for the f/7 and an even bigger Fella is lurking- the Big Fella's big Brother!!.Im hoping that the optics of the set I have now is just as good or better than the first set. Gary


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#30 CHASLX200

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Posted 16 September 2021 - 06:11 PM

F/7 is the only way to go for bigger scopes in my book.  I would love a 14" F/7 for planets with a 5mm eyepiece and barlow.



#31 FalaHomma

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Posted 20 September 2021 - 09:29 PM

I have an old Coulter 8" F4.5 mirror that has been put into a modern Orion OTA with an older custom Wyorock focuser. It seems to be pretty good, but yeah, there's a lot of coma if you use it for imaging. Still I like the views it gives.
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#32 Chuck99

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Posted 21 September 2021 - 05:29 AM

I bought the 17.5 inch f/4.5 mirror (79.2 inch focal length) with a 4.0 inch elliptical secondary mirror (bought separately from Enterprise Optics as I recall) back in 1982 and built an equatorial mount for the scope (20 inch ID sonotube) followed later by a home-made Dobsonian mount for the same OTA.  It is still my main instrument for deep sky and even planetary observing at full aperture.  The optical quality is excellent on this particular Coulter primary mirror as a star test shows and it gives excellent planetary detail even at full aperture.  It currently has a ~25 year old Clausing Beral coating which is still holding up well.

 

Chuck


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#33 pbealo

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Posted 21 September 2021 - 08:38 AM

In addition to the CT-100, I also have the accessory f8 mirror/cell assy and long mounting bar. Its used with the CT-100 secondary/focuser assy. I wonder if they sold many of these??



#34 Michael Covington

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Posted 21 September 2021 - 09:59 AM

In addition to the CT-100, I also have the accessory f8 mirror/cell assy and long mounting bar. Its used with the CT-100 secondary/focuser assy. I wonder if they sold many of these??

I suspect it was rare.  How good is the f/8 mirror?  I suspect that if I had had it, I would have used it almost exclusively.



#35 SpaceConqueror3

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Posted 21 September 2021 - 05:09 PM

I bought a old, Brown Coulter Odyssey 8 (f/4.5) for my young daughter. It was the perfect height for her at the time and it came with a Telrad which she really liked. I thought the optics were pretty good and we took it to a couple Star Parties over a 2-3 year period. I still have it but it's not seeing much use mostly because of how low it is to the ground. I have since got her a 6" f/8 dob to tinker with.

 

Our 2019 Table Mountain S. P. Residence

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#36 Gil V

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Posted 21 September 2021 - 06:13 PM

Easier to post the link than retell the tale.

http://www.cloudynig...y-odyssey-r2970

#37 clamchip

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Posted 21 September 2021 - 06:23 PM

I still own a blue tube 10 inch, and I'll forever have my memories of wonderful times

owning Odyssey's.

A few of my favorites were and forever Stumpy and Bluey.

Robert 

 

post-50896-0-62785700-1550943824.jpg

post-50896-0-94579100-1522075677.jpg


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#38 Mr Magoo

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Posted 21 September 2021 - 08:12 PM

My 1980 Odyssey 1 had a mirror that was about 1/2 wave. Total mush and lots of coma. I tell people that if you buy one it better come with test data or plan on having it refigured. 



#39 Augustus

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Posted 21 September 2021 - 08:27 PM

My 1980 Odyssey 1 had a mirror that was about 1/2 wave. Total mush and lots of coma. I tell people that if you buy one it better come with test data or plan on having it refigured. 

Just an FYI, coma has absolutely nothing to do with the figure of a mirror. 


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#40 JamesDuffey

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Posted 21 September 2021 - 08:29 PM

There is a story, most likely apocryphal, but probably with a grain of truth, about the guy who was trying to sell his Coulter 17.5 inch. He had bought it when he was young, strong, and foolish. It was used, cheap, and he fixed most of the optical problems with a new secondary and different primary mirror mount. As time went by, he bought better telescopes optically, and easier ones to handle, so the Coulter got less and less use. He also acquired a significant other who thought rationally and asked him why he kept it if he didn’t use it. He realized that nostalgia and sentimentality weren’t strong reasons enough to keep it, so he set out to sell it. He priced used ones and set his price at the mean value, which was quite a bit higher than what he had paid, so he wasn’t sure it would sell. He got a lot of interest, but only in the mirror. He wanted to sell the whole scope to someone who would use it, as it was still a good instrument, if unwieldy. In an attempt to keep the mirror only buyers at bay, he increased the price, figuring the whole was worth more than the sum of the parts. That only seemed to increase the buyers interested in the mirror only.

Finally a buyer came forth willing to buy the whole scope. Upon exchanging the scope for cash on a Saturday afternoon and helping the buyer load it into a van, he watched it drive away without a twinge of remorse.

 

The next day, Sunday, on the way to church, he and his significant other passed the small park about a half mile from his house. As they went past the park parking lot, his significant other shouted “Isn’t that your old scope?”. He stopped, and sure enough, the buyer had driven the half mile to the park, kept the mirror, and stuffed the rest of his scope into the park’s dumpster. The guy didn’t know whether to laugh or cry. He finally removed the secondary and the focuser and left the rest. Not feeling much like church, they went directly to a champagne brunch. 


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#41 bremms

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Posted 21 September 2021 - 10:18 PM

I  have used a few Coulter dobs and had a couple full thickness mirrors. Two 13.1”s, one was bad and one was decent. Two 17.5”s both could only take 100x without breakdown. A friend has a 17.5” in his garage that I haven’t looked through. Had an 8” F6 mirror that was very good. A friend bought that scope. Still have a 10.1 mirror in the closet.. Might have sold it. 


Edited by bremms, 21 September 2021 - 10:20 PM.


#42 apfever

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Posted 21 September 2021 - 10:20 PM

funnypost.gif  I Love it, Love it. That is so classic!



#43 SpaceConqueror3

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Posted 21 September 2021 - 11:24 PM

Long live Stumpy and Bluey (is that a word? smile.gif )...


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#44 CHASLX200

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Posted 22 September 2021 - 05:54 AM

My 1980 Odyssey 1 had a mirror that was about 1/2 wave. Total mush and lots of coma. I tell people that if you buy one it better come with test data or plan on having it refigured. 

Everyone i looked thru was a sea of coma and mush.  I throw them in with SCT's. The Paracorr was a world changer for sure around 1990.


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#45 CHASLX200

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Posted 22 September 2021 - 05:56 AM

Just an FYI, coma has absolutely nothing to do with the figure of a mirror. 

I know.  It's all about speed. I could never live with sub F/4. I know it's the rage these days but give me a 20" F/6 everytime. Back in them days around 1982 we did not know any better and would expect a view like that. Just think if we had Zambuto and Mike Lockwood back around 1980 and the Paracorr. Even the Nagler was just coming out of the factory in 1982. Plus no real collimation tools in them days as well.

 

Love to take you back in time and you can see how boring eyepiece tech was back then before Tele Vue changed the world. We have nothing even close to what we have today back in them days.


Edited by CHASLX200, 22 September 2021 - 06:01 AM.

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#46 JamesDuffey

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Posted 25 September 2021 - 10:36 AM

Speaking of which:

 

https://www.facebook...83376640590215/ >


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#47 Claytoncramer

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Posted 26 September 2021 - 09:32 AM

I bought the 17.5 inch f/4.5 mirror (79.2 inch focal length) with a 4.0 inch elliptical secondary mirror (bought separately from Enterprise Optics as I recall) back in 1982 and built an equatorial mount for the scope (20 inch ID sonotube) followed later by a home-made Dobsonian mount for the same OTA. It is still my main instrument for deep sky and even planetary observing at full aperture. The optical quality is excellent on this particular Coulter primary mirror as a star test shows and it gives excellent planetary detail even at full aperture. It currently has a ~25 year old Clausing Beral coating which is still holding up well.

Chuck



#48 Claytoncramer

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Posted 26 September 2021 - 09:38 AM

Showing my age I think. In the late 1960s, Coulter advertised 1/25th wave. My father bought an 8" f/7 mirror from C&H Sales in Pasadena for $50 and we built a telescope from it. I still have it because it continues to turn out images that convince me 1/25th wave was real not hype. My 17.5" f/4.5 Coulter mirror (since refigured) in a Dob is great for light gathering and sometimes produces good 500x images. That 8" my father and I built has on very rare occasion given me sharp images of the Moon at 700x. I am putting it on a new Losmandy G811G today or tomorrow.

Edited by Claytoncramer, 26 September 2021 - 09:39 AM.

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#49 CHASLX200

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Posted 26 September 2021 - 10:42 AM

Showing my age I think. In the late 1960s, Coulter advertised 1/25th wave. My father bought an 8" f/7 mirror from C&H Sales in Pasadena for $50 and we built a telescope from it. I still have it because it continues to turn out images that convince me 1/25th wave was real not hype. My 17.5" f/4.5 Coulter mirror (since refigured) in a Dob is great for light gathering and sometimes produces good 500x images. That 8" my father and I built has on very rare occasion given me sharp images of the Moon at 700x. I am putting it on a new Losmandy G811G today or tomorrow.

Hard to mess up a 8" mirror slower than F/6. Can't beat any old school slow Newt.


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#50 PETER DREW

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Posted 26 September 2021 - 06:00 PM

We (UK) bought a few 17.5" Coulter mirrors, they were cheap enough to have them economically refigured, had one that was good off the shelf.  Never had an Odyssey Dobsonian but built effectively a replica with a 30" F4.1 in 1985 for Halley's Comet.


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