Unitrons

[Tropo-Bob]

I found this old catalogue during a house clean today.

The Unitrons were the dream refractors of their time. I brought Model 114 in 1975 for $280 and my friends were astonded that I paid so much for a telescope. I still own it.

Anyway, for those that will enjoy a trip down memory lane: The full catalogue is attached.

[sharpiel]

I have seen that entire catalogue manifested in reality, in person, in Steve's (UniPol's) double garage :rofl::rofl::rofl:

[sharpiel]

I also owned the 3" as a teenager. Wish I still had it now. Some telescopes are as beautiful to look at, as through.

[brian nordstrom]

:thumbsup: I was given a Model 114 years ago as a restore , and that I did as it's build was very solid . I was totally impressed and tried to do this lovely scope proud to give it a 2nd lease on life so ,,,,

I spent about 6 months on it and in the end it turned out to be a great little 60mm f15 refractor and the Alt/Az mount was solid and easy to use .

I donated it to the ' Northland Astro Society' in NZ as a piece for visitors to look at .

Unitron of the day were a bit of a mixed bag eg. some good and some exceptional optically but it was the mechanics where they really shone :thumbsup: top shelf gear for sure .

Brian.

[synthguy2]

I miss those days. I was lucky enough to get one of the last Cave Astrola 8" Newtonians before the company went under. It took a year (and a lot of intervention by my Uncle in the US) before they actually delivered the scope we'd paid for on a trip over there. It was a great scope, but their customer service and record for not honoring orders was what caused them to go under.

[Ken]

I also have the same catalog with my 3" model 129, nice finish on the mechanical parts. I took it with me to the spsp last weekend to sell but ended up bringing it home again.
Clear skies Ken.

[UniPol]

I think the Model 129 (Alt/Az) and Model 131(Eq) were the best all round versions in their time. Not too heavy, excellent optics, beautifully made and easy to transport. It was the only model in Polarex/Unitron's line up which was F16, all the other versions were F15. Back when, 3" refractors were considered an ideal size for most amateurs. Coupled with modern 1.25" eyepieces their performance is quite satisfying.

[Tropo-Bob]

Yes, the 3" exceeds the Condrady standard (of 5 focal lengths per inch to reduce CA), which makes it a good telescope for planets and doubles.

Funny thing though, I used to dream of having the 5", which I am guessing would have shown much more CA. The Unitrons did not scale up well and all F15s are not equal.

[Ken]

I would like to upgrade to a 1 1/4" eyepiece holder as I don't have any quality .96" eyepieces. Don't know if there is anything commercial available.
Clear Skies Ken.

[Tropo-Bob]

Ken,

Years ago I brought a parks diagonal that fitted the .96" rack and pin and could take 1.25" EPs. However, I have not noticed any currently being advertised.

[Ken]

Thanks Tropo Bob I have a cheap Tasco type diagonal that changes sizes but would like something better quality.

[ausastronomer]

Hi Ken,

I hope you and Cath are well. I was hoping to catch up with you both last weekend at Shoalhaven Heads, but then I realised you would be at SPSP. Unfortunately, I don't get to SPSP very often as it is usually too close on the back of Ozsky; and its a long drive for me for 1/2 a nights observing :)

All is not lost if you're prepared to spend a few $$$ on that 3" Unitron :)

I am not sure of the exact inside diameter on that scope tube but this GSO 2" Crayford will go very close to fitting your tube. It would be close and you could either turn down the supplied adapter a touch to fit the tube, or make a small adapter ring to fit if the tube was slightly oversized.

https://agenaastro.com/gso-crayford-focuser-refractor-telescope-dual-speed-86mm.html

This is the dual speed version for $US137, or you can get a single speed version for $US105. Don Whiteman from BINTEL could probably order you one in as they sell GSO gear.

There are also a couple of other options which are no longer made, but pop up every now and then 2nd hand on Astromart. Both companies have long closed down but their products still float around from time to time on the 2nd hand market.

WyoRock used to do beautiful focusers machined from aircraft grade aluminium for both refractors and Newtonians. Image of a 2" Wyorock on a C80ED. They looked really expensive but were only about $US150 new (less than 1/2 that of a Moonlite at the time). They went out of production in about 2008 or 2009. Steve Lee has a Wyorock Focuser on his 20"/F4 Newtonian and it is very nice. Not a Feathertouch but a nice focuser!

The other one which pops up occasionally are Crawmach focusers made by Meridian Telescopes.

Cheers
John B

[ausastronomer]

Hi Bob,

Nice find !!

I have fond memories of catching the train as a teenager to St Leonards station and walking the km or so to Amateur Astronomy Supply Company (later Astro Optical) at Crows Nest, 3 or 4 times a year to admire the Unitron Refractors on display (long row on the left as you walked in) and talking things telescopes and astronomy with the staff and owner Eric Whitcombe (later Monte Ash).

Cheers
John B

[UniPol]

Polarex/Unitron 1.25" adaptors could be purchased as an accessory, the simplest being the 0.96"/1.25" shown in the picture along with the reversible adaptor usually found on the 3", 4", 5" & 6" models as standard. Rotary eyepiece selectors (Unihex as known in the US) came in three versions ; Model A - 5 x 0.96" & 1 x 1.25", Model B (shown in pic) - 6 x 1.25" and the Super Rotary Selector - 4 x 0.96", 1 x 1.25" & 1 x 2". 1.25" prism diagonals could also be purchased. The eyepieces were a friction fit in the holders and posed no real problems but some of the current 1.25" TV eyepieces are probably a bit heavy to stay put at least on the eq scopes.

[ausastronomer]

Hi Steve,

Those .965"/1.25" adapters worked fine in their day. Depending on what eyepieces Ken wants to use, they may adequately suit his needs now. If he is only going to be using shorter focal length, narrower FOV eyepieces then they will work fine. If he plans on using longer focal length, or wider FOV eyepieces like 24mm TV Panoptic, 20mm Pentax XW, 32mm TV Plossl etc those adapters might vignette somewhat. How bad, I am not sure. It may or may not be to a noticeable degree.

Cheers
John B

[Ken]

Hi John thanks for the info on focusers but at the moment I would like to keep it as original as possible. I was thinking of replacing or making a new screw on 11/4" fitting on the end of the draw tube with locking screw to hold heavy accessories.
Clear Skies Ken.

[Ken]

Thanks Unipol no one knows more about unitron than you lol. The rotary selector is something you don't see these days. I don't know why they only had push in friction fittings holding the diagonal in place.
Clear skies Ken.

[UniPol]

Here's a link for Unitron eyepiece adaptors in the US Ken, might be handy : http://astronomy-shoppe.com/?page_id=1730

[Ken]

Thanks Unipol that is exactly what I was looking for, they are not giving them away though lol. The Aussi dollar and gst suck.:(:(
Clear skies Ken.

[UniPol]

Yep, I think they are a pretty exxy especially if you add post and GST. Even if you get someone to make one here it would be relatively costly owing to labour and material which has to be machined, threaded and tapped.

[Ken]

I made my own today drilling and grinding the original and fitting it to a old damaged Tele view diagonal eyepiece holder. I just had a look at Jupiter with it and was impressed by the view. Now all I need is a good quality diagonal and eyepieces and I should have a nice little planetary scope.
Clear skies Ken.

[torana68]

I’m guessing there are a few closet Unitron owners , must be, they keep popping up for sale.

[Wavytone]

Museum pieces IMHO. Lounge-room ornaments, if you have the space. They looked the ducks nuts, but the optical quality was rather variable and I wasn’t prepared to take the risk on a dud after having a previous scope turn out to be disappointing.

The good ones are a testament to why f/15 was (and still is) nirvana for lunar& planetary types, and its a great shame long-focus refractors aren't made anymore.

It’s also a shame Unitron chose to die, rather than embrace several changes and show what could have been:

- modern ED glass types,
- 2” Crayford focussers,
- mounts with modern electric drives on both axes, with auto guider inputs and encoders.

Opportunity long lost.

[UniPol]

Yep, that's exactly what I've done with one of my Unitron 4" pier mounted photo equatorial 132E refractors from the early 1960's. It takes up virtually no floor space at the top of the stairwell. Note that my Unitron is fitted with a Bintel 2" Crayford focusser which was fitted just to try out modern eyepieces. No mods to the tube were needed so the Unitron focusser can be refitted to keep it original. This particular pier model is fitted with a weight driven clock drive much nicer than an electric one.

[torana68]

Nice :)