Has Anyone seen this Polarex/Unitron turret eyepiece holder before?

[mr bruess]

Has Anyone seen this Polarex/Unitron turret eyepiece holder before?

My Polarex Diameter=60 focal length =700mm(same or similar to unitron model 760) has an unusual turret eyepiece holder.
It does not sit at right angles like the usual Unihex but rotates eyepieces straight.You look at the eyepiece straight ahead through the telescope.
The turret can take 3 eyepieces which screw into the holder.
it takes .965 eyepieces.
I've done some research on cloudy nights etc. but have not seen this type of turret before.
It must be extremely rare and is a must for unitron/polarex fans.

[Wavytone]

Yes I have. I know someone who has had one - and a Unihex - since the 1970's.

That Polarex type never caught on - 3 eyepieces isn't enough, and 0.965" was obsolete even in the 70's.

The Unihex also had one huge advantage - it had a threaded hole to take a very big 60mm Kellner (Unitron) that was ideal for these f/15 refractors. That eyepiece is close to the modern 2" Barrel size and has the mating screw thread cut directly on the barrel.

The 0.965" eyepieces had a very limited field of view due to the small barrels.

The interesting part is that the hexagonal body of your Polarex looks suspiciously the same as the Unihex body, suggesting the Unihex parts were cannibalized to make that.

Possibly collectible, but a Unihex remains a lot more desirable !

[UniPol]

Esdailes & Sons (Glebe/Parramatta) sold the three eyepiece rotary selector back in the late 1950's to the mid 1960's for the Polarex Junior series refractors (see scanned page from Esdailes' catalogue 1962). The six eyepiece rotary selector was intended for the senior series refractors.

Polarex (Europe, Asia Pacific) called these multiple eyepiece holders "rotary eyepiece selectors" and Unitron (USA) called them "Unihex's". In all, Unihex's/RES's came in a Model A - 1 x 1.25" & 5 0.965" EP's, Model B - 6 x 1.25" EP's & Super Unihex/RES - 1 x 2", 1 x 1.25" & 4 x 0.965" EP's. The 2" EP for the Super U/RES model was strictly a 60mm Kellner which was of the screw in type.

[Wavytone]

Here's the Unihex

http://www.cloudynights.com/ubbthrea.../o/all/fpart/1

Scroll down to the bottom to see one with eyepieces fitted. One aspect of the Unihex is that it requires a lot of back focal length and probably would not fit on most modern refractors unless you shortened the OTA. Unitron took advantage of this to shorten the optical tubes a tad (f/15 refractors are long) - with a Unitron scope, if you use modern eyepieces and a star diagonal instead of a Unihex the drawtube will need to be pulled a loong way out to focus the eyepiece. It's definitely not for short-focus reflectors !

The Polarex thing you have doesn't need so much back-focal length.

[UniPol]

Unihex's/RES's use the same prism diagonal as standard right angle diagonals so there is no difference in back focus.

[mr bruess]

Originally Posted by UniPol

Esdailes & Sons (Glebe/Parramatta) sold the three eyepiece rotary selector back in the late 1950's to the mid 1960's for the Polarex Junior series refractors (see scanned page from Esdailes' catalogue 1962). The six eyepiece rotary selector was intended for the senior series refractors.

Polarex (Europe, Asia Pacific) called these multiple eyepiece holders "rotary eyepiece selectors" and Unitron (USA) called them "Unihex's". In all, Unihex's/RES's came in a Model A - 1 x 1.25" & 5 0.965" EP's, Model B - 6 x 1.25" EP's & Super Unihex/RES - 1 x 2", 1 x 1.25" & 4 x 0.965" EP's. The 2" EP for the Super U/RES model was strictly a 60mm Kellner which was of the screw in type.

Thanks guys for the Informative reply.Especially to UniPol.I read with great interest your post on the turret eyepiece.
You really know your stuff.
I'm glad I own such a very rare Polarex telescope and eyepiece holder.To think it is half a century old!
The instrument was made in the early to mid 60's
I'm a big fan of Vintage refractors for their outstanding Quality.and collectibility My Polarex/Unitron has a 1 knob focuser on the right hand side.(you can see from the pictures).
The draw tube can be pulled back by hand to achieve focus. The push/pull drawtube is very smooth.
The Alt/Az mount has an unique clamp and latch style cradle which securely holds the OTA in place.
The tripod is missing the chain spreader so I'm going to have to find one.
I repaired the Wooden box it came in by going to bunnings and obtaining plywood(which was cut to size by them) and nailing it to the bottom of the wooden box.

To UniPol I see that you have a big collection of Unitron/polarex telescopes.
I'd like to come over to your place one day and see and photograph them,especially the 6 inch monster Unitron refractor on a pier mount.You must be the only person in Australia to own such a Large Unitron refractor!I wonder where you got it?
It would be like visiting the musem of telescopes which the Australian Museum doesn't have but should have.

[mr bruess]

new pictures