How Many Of You Ever Owned A Coulter... back in the day

[Preston Pendergraft]

I can say I had one... a 8in f/4.5 Odyssey 8 I got in junior high school, I sold golf balls to pay for a Telrad and eyepieces to use with it.

The optics were terrible compared to scopes of today. And that "focuser" was very low frills! Anyway, I picked up some new observing guides and there were several references to 13.1 and 17.5 inch scopes in them. About all those could be are old red Coulters!

[Dragan]

I can't say I ever owned one, but a friend owned a 13.1 Coulter and I looked thru it frequently. You're description above is pretty spot on. He ended up trashing everything but the primary, refiguring it and rebuilding the entire scope to his liking. This was the mid nineties. At the same time, I owned a 10" Meade Starfinder and that didn't perform much better. I feel I needed to make endless mods just to get it to perform adequately.

[Steve Gottlieb]

Preston, the really old Coulters were the original blue ones -- I should know as I had both a 13.1" and a 17.5", purchased soon after they came out in the 1980's! I paid under $400 for the 13.1", which had an OK mirror. The 17.5" was also ridiculously cheap, but the optics were pretty poor and I had the mirror refigured.

[FaintFuzzies]

Yes, the originals way back then was the blue boxed scopes with a round tube sticking out of it.


1412
Original Blue scopes


1413
Newer red scopes

[yapo]

I've got one, the red 17.5" model from about 1994... Poor optics also, that only allows for power up to 300-400x, but still my observing buddy for years (I wish I hade the money to have it refigured...).

[Bigdob24]

I ordered a 13.1 in 1986 and recieved it a year later. At the time it cost $499.
I used it and learned the sky, lots of fun.
I then ran into a guy that had built a few scopes and he asked if I had ever collimated it?
I said what's collimation? We worked it over and it turned out to be one of the better mirrors , I saw red color in M42 , that was almost 30 years ago, younger eyes and an above average night in Central IL I'm sure.
It was a great starter scope and was sold to buy a 20" .
The start of appature fever

[Steve Gottlieb]

I mentioned I paid less than $400 for the 13.1-inch, but then I started to question if that was possible. Yep, here's the original ad

1441

[rmollise]

The Odysseys weren't much...BUT...for those of us coming from the small scopes of our youths in the 60s, they were a revelation. I got my first look though one in the 80s, an Odyssey II. No, the optics likely weren't very good...but it didn't matter. One look at M13 through a 17.5-inch had me picking myself up off the ground. It was the first look I'd had through a Nagler, too, which ruined my Erfles and Orthos for me. :lol:

Whether blue or red, Jim Braginton/Jacobsen's scopes were humble things, but they opened a lot of eyes to the deep sky. ;)

[KidOrion]

Mine (13.1) was/is pretty good optically. Never used high power with it, but I've rarely had seeing good enough anyway. It was pretty uncollimatable--as if someone had gotten it collimated and glued everything in place. The mirror cell got mutilated in a move (Alaska --> Illinois) and I haven't yet built a new one; I'd intended to convert it to a truss-style and never finished the job. Been thinking about keeping it in the old red tube and getting it back in action (with new focuser, cell, and secondary assembly), despite also having a Discovery truss-type with Ostahowski optics. I hate seeing a scope not getting to gather starlight.

[star drop]

I bought a used blue Odyssey I in 1981 and used it up until 1989. It performed well even up to 312x using a 4.8mm Nagler but the seeing rarely cooperated. When I got a 25" Tectron the Coulter just sat and was sold a while afterwards. Currently the new owner has not used it in years.

[omahaastro]

I always dreamed about owning one of those 13.1/17.5" Coulters when I was young. Anyone remember the 29" ones?! (or was there only one?)

[star drop]

I think that Coulter made three 29" telescopes. I know of a 29" Coulter mirror near me in a homemade telescope but I have not seen it in person.

[Galaxter]

I still have and use my 10.1" red Coulter Odyssey that I have used since 1992. The mirrors are ok.. nothing great. I never had them re figured and had them re coated a little over a year ago. This was what I could afford back then to get me into DSOs when I was first going after the Messiers and Herschels. It has always worked pretty good for showing them at low and medium powers, but the mirrors have never been good enough to consistently show these objects at high powers. I also have a 12.5" Starsplitter truss Dob. with much better mirrors, but it is more difficult to transport and set up than the much easier to deal with 10" red Coulter, which is almost a grab and go scope with a strong handle I have bolted to it where I can just pick it up and move it like a suitcase.

Phil

[Tom Dey]

I think that Coulter made three 29" telescopes. I know of a 29" Coulter mirror near me in a homemade telescope but I have not seen it in person.

Hi star drop et all ! I'm New to this Forum and glad I found it ! I believe I'm the guy you reference, live in Springwater, NY and indeed have the 29-inch up and using it. The cell is from AS 27-point whiffle tree and I built the scope as a pretty standard truss AS-like but beefed up because it is in a dome (Luxury!) The BIG improvement I made was to add 12 force-actuators around the mirror judiciously-placed twixt the tree triangles to mechanical ground. I invented that and call it the "Tweaker Clock." It comprises simple (pull) springs tuned with wing nuts. These pull on the back of the mirror against mech ground making it "heavier" (AKA mass-density) where pulled. My intent was to tweak out axial (global) astigmatism just by racking thru focus as my son twisted on the wing nuts. What it does is to pull the shorter astigmatic surface radius Longer to match the longer one. Long story short - It works magnificently! Very objectionable astigmatism reduced to undetectable with only a blush or (Zernike) Trefoil left. The mirror went from depressing to Very Good! I use it routinely at 400X+ with the brightest stars showing only slight triangle shape and the dimmer ones looking like dots. Central star in the Ring always easy. Umm...I got it recoated at EMF (Evaporated Metal Films) which is close to here and high-quality EnAl, fair price and personable staff. I LOVE this scope! I'm on 16 acres in Upstate NY Rural Hills - surprisingly DARK for NY! Other equip: 20+ TV eyeps, 3ea ITT Gen 3 Night Visions, JMI RB6 and RB16, APM 100/90 deg Binos, Zeiss 20x60 IS Binos. I had another Coulter 29 but sold it off. Jim Jacobsen knocked himself out trying to produce the 29s but lost his shirt on them. Fortunately, mine ONLY suffers astig, but I found this solution which works magically and holds figure very stable! The mirror is otherwise very smooth and the correction (parbolization) is text book perfect. I’d like to post pictures of this stuff if there is a way. Tom Dey pics--->>> 186018611862

[Ivan Maly]

Hi Tom. Let me welcome you here. I was the guy who showed up once with Carl M. at your place. Magnificent dome it is that you've got there at the top.

[shneor]

OK, it's months late, but I had one of the first Coulter 13.1" ers, big, blue and boxy. I built a shed for it in my back yard and drove it to Blue Canyon for observing. It was $400, a terrific bargain. I did not have many eyepieces at the time. As I recall, images were ok, but it was a bear to use. I sold a 6" reflector on a pier for $200 to help pay for it, as I was a poor grad student at the time.

[kisspeter]

I've never had a Coulter but it was the first bigger scope I could take a look into. A friend (Gábor Szitkay) bought it in the early 1990's (the red 17.5"). It was the biggest amateur telescope in Hungary for at least a decade. Many good observation were made using the "Red Devil" mainly at the hands of Gáspár Bakos - now a pro astronomer and exoplanet hunter (HATNet).

[Paul Chuck]

Hi star drop et all ! I'm New to this Forum and glad I found it ! I believe I'm the guy you reference, live in Springwater, NY and indeed have the 29-inch up and using it. The cell is from AS 27-point whiffle tree and I built the scope as a pretty standard truss AS-like but beefed up because it is in a dome (Luxury!) The BIG improvement I made was to add 12 force-actuators around the mirror judiciously-placed twixt the tree triangles to mechanical ground. I invented that and call it the "Tweaker Clock." It comprises simple (pull) springs tuned with wing nuts. These pull on the back of the mirror against mech ground making it "heavier" (AKA mass-density) where pulled. My intent was to tweak out axial (global) astigmatism just by racking thru focus as my son twisted on the wing nuts. What it does is to pull the shorter astigmatic surface radius Longer to match the longer one. Long story short - It works magnificently! Very objectionable astigmatism reduced to undetectable with only a blush or (Zernike) Trefoil left. The mirror went from depressing to Very Good! I use it routinely at 400X+ with the brightest stars showing only slight triangle shape and the dimmer ones looking like dots. Central star in the Ring always easy. Umm...I got it recoated at EMF (Evaporated Metal Films) which is close to here and high-quality EnAl, fair price and personable staff. I LOVE this scope! I'm on 16 acres in Upstate NY Rural Hills - surprisingly DARK for NY! Other equip: 20+ TV eyeps, 3ea ITT Gen 3 Night Visions, JMI RB6 and RB16, APM 100/90 deg Binos, Zeiss 20x60 IS Binos. I had another Coulter 29 but sold it off. Jim Jacobsen knocked himself out trying to produce the 29s but lost his shirt on them. Fortunately, mine ONLY suffers astig, but I found this solution which works magically and holds figure very stable! The mirror is otherwise very smooth and the correction (parbolization) is text book perfect. I’d like to post pictures of this stuff if there is a way. Tom Dey pics--->>> 186018611862
Hi Tom,

I am the first person to have ordered a 29'' Coulter mirror (according to Coulter). During two years, roughly every month, Mrs Dorothy Jacobsen replied to my claims not to worry : the mirror would be shipped next month to France where I am living. I remember I was afraid of an upcoming bankruptcy of the company. But as I was living far away, it was difficult and expensive to hire a lawyer to recover my money. Then, I noticed in the reviews Astronomy and S&T that some 29'' have already been sold and were used. I though wrongly that as I was the first to order a 29 '' , I would be the first to get one.
Fortunately I had then a bright idea. I made to the editors of Astronomy and S&T a copy of the whole correspondence I had with Mrs Jacobsen, asking them to stop Coulter advertising. By return mail, S&T wrote me that they have sent a telegram to Coulter company asking them to ship the mirror within 15 days.

Very efficient indeed. The mirror was in France 3 weeks later. Since the mid 1980 the mirror is installed on an offset cradle mounts which allows to point the polar. In addition, that mount is very stable. In my telescope, the counterweight is about 1000 kgs. Very kindly, Jean Texereau has calculated for me a cell with 15 astatic levers. The result is far from perfect but good up to 150x magnification, due to the imperfect optic.

May be your idea to add fixed constraints on the mirror to correct its optical surface could help me a lot.
Where and how do you glue the 12 springs at the back of your 29'' ?
Please, perhaps could you send me a scan of a layout of your cell and pics on details of the cell ?

[carolinaskies]

I had one of the old 'box' style Coulter 13.1" about 16 years ago. Sold it due to the heavy weight and having an LX200 and acquiring a 16" Starfinder mirror for a future truss project. Sadly I lost my job and had to set aside regular observing and the truss project.

The sling style box setup was notoriously bad for having to colimnate and for the mirror moving slightly as you went vertical. Still it was a fun telescope for fuzzies that smaller scopes just can't reach.

Fortunately for me a couple weeks ago I actually found another 13.1, this time a red tube version. Found it in the local thrift store of all places! I have yet to use it for first light to check optics, but I will try it out next month as our southern skies stabilize with the temperature drop.