8 replies to this topic

[2manyscopes]

Hi all,
I have been quietly searching the internet for several years for info about the 4" & 6" Cave refractors. Unfortunately, there is very little info out there.

Given the reputation of Cave I would have expected to meet atleast a few amateurs who owned Cave refractors. Maybe the market was so strong for larger aperture scopes that the long focus refractors were overlooked or not even considered.

I am primarily interested in learning who made the objectives for these scopes? Did Cave do them in-house? I have read several internet postings indicating that D&G Optical made them for Cave. In my correspondence with D&G, they state: "No, we never supplied objectives or tubes directly to Cave." They could still be D&G objectives if Cave bought complete OTA's from a maker that used D&G objectives. I have no idea who made the refractor tubes but the newtonian tubes apparently were supplied by Parks.

Did D&G sign their objectives or cells? Did other potential makers of the day sign their objectives?

In discussions with the seller of the 6" f/15 Cave refractor on Astromart, he states that the objective is original to the scope and was made by D&G as stated to him by the original owner who purchased the scope from Cave.

Any information about the 4" & 6" Cave refractors would be appreciated.
Thanks,
Bill

[petrogeoman]

Hi Bill,

It is my understanding that the 4" and 6" Cave refractors used Jaegers objectives. D&G wasn't around when Cave was in business.

[macpurity]

Jack Harper has put on the web, a scan of the 1975 Cave Optical catalog. Here is a link for the first page having to do with Cave Refractors, and here is a link for second page. I'm not sure if these answer your questions, but it gives you some further information.

And Harper's main Cave page is here.

[2manyscopes]

Hi Bill,

It is my understanding that the 4" and 6" Cave refractors used Jaegers objectives. D&G wasn't around when Cave was in business.

Thanks for the info Paul.
Bill

[2manyscopes]

Thanks. I have a 1970 Cave catalog that shows the same info I believe. I'll have to compare the two and look for differences.
Bill

[Lew Chilton]

I wonder if Cave sold the refractors with the Jaegers objectives as-is, or at least tested them first before mounting and selling them as Cave telescopes.

I owned a Jaegers 6" f/15 coated objective** which performed well, but one of the old-time lens makers in our club tested it and said he could improve its performance by removing a zone that he saw. He polished the r-1 surface to effectively cancel out the zone. When he returned the objective to me, you could see where he had been polishing because part of the MgFl coating was now missing from the front element. I couldn't tell the difference with regard to the coating, but the lens did seem to perform a little better.

**When accurately measured, the f-ratio was actually 14.4, not 15.

[2manyscopes]

I wonder if Cave sold the refractors with the Jaegers objectives as-is, or at least tested them first before mounting and selling them as Cave telescopes.

I owned a Jaegers 6" f/15 coated objective** which performed well,

I wonder if Cave made the tubes for the refractors or farmed that work out?

I have yet to star test my 6" f/15 as it is in Oregon right now. I plan to pick it up it this Saturday.
Bill

[Serenity Now]

There has been a 6" Cave refractor listed on Astromart for sale recently. Location is Texas.In my discussion with him he stated the objective was Jagears...D&G was not around when those refractors were built.

[Mike Rapchak]

Mac,

Wow, was it a trip viewing the pages from that 1975 Cave catalog! Many thanks for sharing it with us! I used to have one of them; funny thing is I got my copy sometime in the late 1960s; I see that they were still using the same pictures in the '75 version. IMO some of these photos date back to the early '60s/late '50s (check out the clothing and hair styles on some of the models - especially in the b/w pics). Priceless!!

Mike Rapchak Jr.
Hammond, IN