Edmund fork mounted 8" f/5
Posted 20 June 2004 - 10:53 PM
I'm new to the Cloudy Nights forum and I'm excited to announce that I just won a classic Edmund fork mounted 8" f/5 on a certain auction site. I hope it ships sometime next week so I can have first light during my upcoming vacation week.
There's a story behind my quest for one of these scopes. When I graduated from high school in 1985, I was going to get an 8" f/5 as my graduation present. I sent in the order and promptly got a letter back telling me that the 8" f/5 was discontinued and there were none left in stock. I was heartbroken, but I still got an Edmund scope. A local doctor had a 6" f/6 on the German pedestal and willingly sold it to me. That 6" scope served me very well for over a decade and even survived a crash that destroyed my car. I eventually sold it because I had acquired an 8" LX200 (first generation) and didn't use it much. I have many, many fond memories of coming home from college and starhopping my way through the Messier Catalog. There was a guy in my home town who had an Edmund fork mounted 6" f/6 and that's the scope through which I got my VERY first view of M57 in, I believe, 1981. I will never forget it.
Anyway, I promised myself that someday I'd find one of the 8" f/5 scopes and I've finally fulfilled that promise. I know I'll get many good years of viewing out of this scope and using it will bring back some very, very fond memories. I got it for less than half of the original retail price and I'm awaiting a final shipping quote from the seller. I'll be happy to post some photos of it here when I get it up and running.
Next on my list is a Questar 3.5".
Posted 20 June 2004 - 11:45 PM
If I recall from the Auction description it did not have the manual. The manual was for both tube assemblys, the 6 and 8 inch. If it turns out you need it let me know, I'll scan and email it. Again , congrats, I'm a bit jealous.
Posted 21 June 2004 - 01:00 AM
I have to say that these fork mounted Newtonians just LOOK really cool.
Posted 22 June 2004 - 09:33 AM
I always drooled over those fork mounted Newts (and lots of other stuff in the Edmund catalog)!
Now you need a complete set of vintage RKE eyepieces and barlow in that cool black plastic case!
Posted 22 June 2004 - 08:45 PM
Posted 23 June 2004 - 01:53 PM
Posted 23 June 2004 - 01:56 PM
Posted 23 June 2004 - 03:35 PM
As for the RKE's, I have the 28mm that came with the scope and a 12mm RKE and a 9mm Circle T ortho I bought at Edmund at the same time. The industrial optics division Edmund Industrial optics which still hold the copyright/patent? for the RKE still sells them. They were not included in the sale to scientificsonline when Edmund Scientific closed.
Posted 30 June 2004 - 09:46 PM
Posted 30 June 2004 - 10:56 PM
Posted 01 July 2004 - 04:45 PM
Posted 02 January 2006 - 04:47 PM
Here is a shot of my 1980 Edmund 8 inch fork mounted reflector. There have been a few changes to it from the original. The red phenolic tube is gone as the scope fell over one night while I was pulling on an electrical cord. In the cold it broke easily so I replaced it with a white Parks fiberglass tube. It was a near perfect fit. The red 30mm finder was replaced by a Meade 60 mm short tube refractor. Instead of the original tangent arm screw for declination corrections I have a 2 rpm Edmund dc motor with sprockets and chain to do the corrections off the 12 volt synchronous drive corrector. the tangent arm is still used with this setup. It has the original drive and clutch and takes super astrophotos. I love the off axis guider and have incorporated similar designs into my own personal homebuilt scopes. Astrophotography could not be easier !
The optics are first class and razor sharp. The f/5 makes this a fast scope with a nice field of view. The scope travels well for an 8 inch and sets up fast once you find the threaded hole for the rod that attaches the legs to the fork head. I have found it solid. The polar alignment is made easier by adding threaded rods to the foot pads to slightly adjust the scope after a rough angle setting on the main head. Being a fork it is easy to align to true pole by setting the tube parallel to polar axis rotation by looking through the main eyepiece as you rotate the scope. Once the stars seem to be circling in the center of the eyepiece use a cross hair eyepiece to find polaris and its star field. Use the cross hairs to center on the point where the true pole lies and you are there ! There are maps that show exactly where the pole lies now. This method is better than using a polaris scope as you are actually turning your whole instrument with its greater magnifying power and light grasp into one.
Posted 02 January 2006 - 06:24 PM
How does that combo focuser work? I'm assuming there is 1 secondary and possibly a series of flats or/and prisms to split the light cone.
Very nice set-up. indeed!
Posted 03 January 2006 - 11:17 PM
The off axis focuser was an option when I bought the scope. There are small thumb screws that you loosen so as to be able to rotate the whole focuser in order to scan the sky circumferencially. Another thumb screw operates one of two prisms to scan radially for guide stars. One of those two prisms is the pick off prism both of which are located underneath the secondary angled focusing tube. It is very easy to find bright guide stars with such a setup and it is easy to get them centered with the thumbscrews and spring loaded prism.