Unitron/Polarex Model 114 60mm Review
How
a telescope should look: the elegant Unitron refractor.
Unitron
telescopes have a classic elegance matched perhaps only by Questar, another
American telescope from the Space Race era. Many amateurs of my age will recall
the Unitron adverts that appeared in magazines like Sky and Telescope in the
60s and 70s, perhaps when they were children just getting interested in
astronomy.
In
Europe, Unitrons were badged as Polarex,
but the telescopes are the same - long glossy white tubes with black fittings
and mounts. Unfortunately, back then telescopes were relatively even more
expensive in Britain than they are now.
So,
my own family couldn’t afford a Unitron (didn’t even know how to obtain one:
the ‘States seemed very exotic back in the ‘70s and the ad’s in my Seventies
Sky and telescopes might have come from another planet). Even the Tasco three inch I bullied my Mum into buying me cost a
whopping £300 in 1977 and had to be imported. I remember waiting all Summer for
it and making my Mum phone the local camera shop every
five minutes to see if it had arrived.
Now,
it seems a fact of life that if you really want something as a child, you go to
great lengths to get it as an adult ... So, of course, having wanted a Unitron
then and having had a thoroughly disappointing Tasco
instead, I still wanted one now.
At
A Glance
|
Telescope |
Unitron/Polarex Model 114 |
|
Aperture |
60mm |
|
Focal Length |
900mm |
|
Focal
Ratio |
F15 |
|
Length |
~1m |
|
Weight |
~5Kg incl.
mount |
Data from Me.
What’s
in the Box?
The Unitron
comes in a an attractive (if scratched now) veneered case with some quality
accessories.
Design
and Build
The
Unitron is packed with stylish retro features like the enamelled white tube, glossy
black castings, logoed Bakelite lens cap and stainless finder tube. This is
classic refractor at its classiest. No gold lens caps or green focusers here.
Unitron
detailing is stylishly retro: enamel white, gloss black and Bakelite.
Unitron/Polarex 60mm F15 objective. It looks like Takahashi; but it
doesn’t perform like one.
Optics
The
Unitron is a 60mm F15 (900mm) achromat. It’s a completely traditional
configuration that can deliver excellent images with very little chromatic
aberration. The lens is a classy-looking affair with a finely engraved lens
ring and good coatings for the times. It looks
vastly superior to the run of 60mm refractors. In practice, Unitron lenses were
made in various small Japanese optical shops and quality isn’t what you might
expect from its appearance.
Tube
The
tube is long and enamelled in a brilliant white. At one end is a push-fit white
dew-shield, at the other various handsome fittings accented in lustrous black.
Did I mention it looks good? The tube comes with a pair of brackets to hold the
rod for a solar projection screen and all such accessories on the Unitron are
made from hard, brittle Bakelite. Mostly the Unitron is a high
quality device, but those Bakelite fittings for the finder and sun
screen holder tend to crack are fragile.
Focuser
The
focuser is unusual - a long, push-fit drawtube and short-travel rack-and-pinion
with the black Bakelite knob (matching the ones on the mount) on the right side
only. The draw-tube provides coarse focusing, the r&p
fine. It would be a good system but there is some flex in the drawtube and it
can ‘sag’ when extended. I found greasing it sparingly tightened things up.
Quirky
focuser combines draw-tube with single-knob rack and pinion.
Mounting
The
tube fixes to the mount head via a little black clamshell secured by a couple
of Bakelite knobs - no dovetails back then. The mount itself is the same black
enamel as the clamshell and the tube fittings, whilst the mechanical bits
appear to be stainless.
The
mount is small and very well engineered and sits on a set of long tripod legs
made of what looks like boxwood. Slow
motion controls – smooth and accurate – are provided for both axes. This is one
of the best alt-az mounts. Also, it must be said, the
mount looks beautiful. You often see them paired with more modern telescopes.
Unitron
alt-azimuth mount head and clamshell.
The
Unitron/Polarex 114 is tall and looks big on its
tripod, but is actually very light and easy to move around.
Accessories
The
Unitron 114 comes packed in a wooden crate with its accessories, like most
quality refractors of the time. That wooden crate contains a high quality 4x
finder in an unusual stainless tube; four 0.965 eyepieces: a Ramsden 25mm,
Kellner 18mm and 12.5mm and a Sym (read Orthoscopic)
9mm; a dangerous looking clip-on Sun filter; a decent 0.965” prism diagonal and
a strange barlow that pushes into the front of the
diagonal.
Sitting
in its box, the OTA looks graceful ... and long! I can imagine some child from a
well-off family in the Sixties, with the Space Race delivering exciting new
discoveries every week, excitedly opening that box for Christmas or birthday.
Unitron
eyepieces: A Ramsden, two Kellners and an Orthoscopic
(‘Sym’).
Unitron
finder is a beautiful thing but the Bakelite rings crack easily.
In
Use – The Night Sky
General
Observing Notes
The
first thing to say about the Unitron in use is that here is a grab-n-go scope
from before anybody ever used that term! The whole outfit is very light, even
on its long wooden tripod and it’s a trivial lift for anyone but the infirm.
Big it maybe, but the Unitron could be used by an older child.
The
Unitron mount is excellent. With practice you can set the tensioners so that
you can push it around, then use the slo-mo knobs for
fine adjustment. Those slow motion controls are both
on the back of the mount and don’t change position much as you slew around,
which is very convenient. They work by moving a lever against a spring-loaded
plunger, so travel is a bit limited; the same mechanism works the declination
axis on my Takahashi P2Z mount.
The
only down-side to the mount is vibration from the long tube, which takes a
while to settle at high powers. Overall, though, the Unitron mount is much more
convenient than a modern TelePod in many ways. At
high power, the TelePod needs lots of nudging, whilst
you just twist the Unitron knobs to keep the object in view, with much less
risk of losing it.
The
field of view from the 0.965” Kellners is very
narrow, so you don’t get the full Moon in the field above about 50x. This makes
finding things unusually painful for a small scope, so it’s a good thing that
the finder is excellent with a wide field, clear reticle
and decent eye relief.
Star Test
Close
inspection of the Unitron’s optics with a star test reveal less than perfect
optics; I won’t say more as it seems churlish to criticise this classic, like
wheel-spinning an old Jag’. I have read that these optics were rarely even
diffraction limited, so this one is doubtless typical.
I
used to think that was just how things were in the 1960’s before modern optical
testing and fabrication … then I acquired a 1964 Swift 838. The Swift has a
superb star test and is super-sharp in-focus, making me wonder why Unitron were
unable to achieve the same level of quality.
The Moon
At
F15, with a 60mm objective and basic coatings, it’s not surprising the Unitron
is at its best on the Moon. With the 25mm Ramsden giving 36x the Unitron delivers
crisp, sharp views, with very little chromatic aberration. The Moon remains detailed
and sharp, with lots of craters along the terminator, in the 18mm Kellner at
50x and even up to 72x in the 12.5mm Kellner.
By
the time you’ve upped the power to 100x with the 9mm Orthoscopic (‘Sym’), the Model 114 has gone all soft and you know it
won’t take much more. The Unitron just won’t take my 7mm Takahashi MC
orthoscopic (in contrast to the Swift 838, which gobbles it up and asks for a
five). The good contrast and well controlled CA demonstrate the potential of a
small, long focus achromat, but you sense that optical quality isn’t the best,
star-test confirmation not required.
Comparisons
with Tele Vue’s tiny TV-60 apochromat are interesting. The TV-60 is a tiny,
black, CNC-made conical object with a helical focuser which looks nothing like
a telescope, but which works extremely well. The Unitron looks much better and
much more how you feel a telescope should. I don’t know if Neil Armstrong had a
telescope, but if he did this is the way it would have looked. However, the
TV-60 is a much better experience to look through.
Unfortunately,
nice though it is on the Moon at medium powers, at higher powers the Unitron
reveals its age compared with the Tele Vue. Using the same 12.5mm kellner in both the Unitron and the TV-60 (with a 2.5x Powermate to equalise the power), the little Tele Vue is
sharper, brighter, much more contrasty. For example,
the Huygens Rille is obvious in the TV-60, much less so in the Unitron. What’s
more, the older scope just doesn’t convey those luminous icy whites, hard
blacks and soft greys, all those subtle maria
shadings the TV-60 excels at. In the end I just put the Unitron back inside,
popped a 5mm Nagler in the Tele Vue and enjoyed the
view.
Curiously,
Takahashi’s latest and best-corrected refractor the FOA-60Q is also a 60mm/900mm
F15. We’d best not compare their performance. Still, I think the Unitron looks
better, don’t you.
Takahashi’s
super-apo FOA-60Q shares the same optical specs as the Model 114, but will take
more than twice the magnification.
Jupiter
The
only planet I tried was Jupiter. The view was adequate, revealing the basic
equatorial belts and Galilean moons, but the view through the TV-60 was in
another league (as is that delivered by the 50mm Swift 838).
Deep
Sky
The
single coatings and long focal length meant I didn’t linger over deep sky
testing the Unitron. Sorry.
Summary
The
Unitron looks frankly beautiful and is very well made. I’m admiring it from
across my living room as I write. It may perform much like a cheap 60mm Ebay telescope from today, but of course looks and build
quality are in a whole different league. Even that’s an unfair judgement,
because the Unitron is from an era before ray-tracing programs and laser
interferometers and CNC optical grinding machines and multi coatings.
Think
of the Unitron like a classic car. It works nicely for the era and age; just
don’t scrutinise the star test too closely, or try comparing it with a TV-60.
Looked at, the little Tele Vue is a
dumpy object of indeterminate purpose, compared to the elegance of the Unitron;
I know which I’d rather have in my living room! But compare the view through the two and the Tele Vue is superior
in every way and proves that nostalgia ain’t what it
used to be.
But
did I mention that the Unitron looks good? Really, really good. Superficial, moi?
Recommended
as a magnificent-looking classic. But if you want an antique with performance
to match its looks, buy a Swift instead.
Beautiful as Questar, but
you’d hang your hat on the Unitron if someone offered you a view through a Tele
Vue.