Hi this is Graham from Jenham's Astro. A while ago I reviewed a 60-millimeter
Princz refractor that I bought online from an auction website and that scope
dated what was the 1980s and I guess I got the bug for looking at older
refractors and I started looking around for a larger aperture scope and came
across a three inch achromatic refractor on a website for sale with
its all this accessories, it's equatorial mount and its original case so I bought
this go for £100 and I'm hoping that it's going to turn out to be a good
buy so this particular one has got an objective of 76.2 millimeters diameter
and it's got a focal length of twelve hundred and fifty millimeters so that
gives it a focal ratio of 16.4. When I've done a little bit research of this
sort of scope there are relatively few with this particular focal length and
there are a lot more with the same objective but with a twelve hundred
millimeter focal length. Either way with that sort of refractor you really expect to
get almost no false colour. I don't know much about where this scope came
from originally so I'll talk you through some of the features and we can see what
clues will get from from those about its origin. The brand
on this particular scope is "Astro" which couldn't be more generic .
looking to the cloudy nights and the stargazers forums where there's
quite a lot of correspondence about classic refractors and this told me
that this scope was marketed under different brand names in different
countries so here in the UK this scope was the Prinz 660 and whereas in other
countries I've seen the examples where the brand name was Dean Beam, OKKK
Royal Astro, Yamatar and a few others besides. You can see on the focuser that
there is a small K inside a circle so I'm calling this a Circle K model
originally I thought that that meant the manufacturer was a company called Kenko
versus Towa for the CIrcle T 60 millimeter scope in my previous video
but apparently things are a little bit more complicated than that and the scope
could have been made by Towa and sold by another company called Astro Optics
maybe it was the other way round. unfortunately this particular unit doesn't have a
serial number so that may make things a little bit more difficult in terms of
identification some good news rack and pinion focuser still works pretty well,
applied a bit of grease and perhaps more importantly the focuser draw tube is
large enough to allow adaptation to modern eyepieces so you can unscrew
standard adapter and on the end of the draw tube there is a thread inside which
is called a vixen thread and it's thirty six point four millimeters in diameter
and it allows you to swap the original adapter for a more modern example so
here's one from Baader planetarium but there are other examples which you can
buy and you simply screw that any place in the original adapter and you'll then
in a good position to to use one and a quarter inch eyepieces okay so if we
start with a finder I read that it can be a feature that helps you distinguish
between the many similar scopes this one the only obvious mark on it to me is the
magnification which is x 6 written on the eyepiece end, it attaches a single screw
to a bracket on the plate on the side of the tube I've read that if you look
underneath this plate on some scopes there is manufacturer's mark but not on
this one there's nothing on the bracket nothing on tube no obvious mark is I can
see so I think if there's an expert who can tell me something about
of the bracket itself well that might be a clue but there's nothing that really
tells me anything further around the year the manufacturer so if we move on
to the objective the dewshield is attached just with some felt and just
pulls off and then I think you can see that this objective lens has got three
spacers around the lens there are no markings i can see certainly no obvious
markings on the lens cell either on the outside or if you unscrew the lens
cell from the tube I haven't found any markings on the inside but again an
expert might be able to tell me if there's something a little bit cryptic
that might not be obvious as an identification. Looking inside the tube
itself there are a set of three baffles and I've read that on some of these
scopes the inside of the tube between the two central baffles as it were has
not been painted and in fact it looks to me if I have a closer look along this
tube that that's the case for this particular scope perhaps just due to
manufacturing it was deemed that it wasn't necessary in order to stop reflections
of light and probably would have been just difficult to reach that part of the tube
ok so moving on to the mount I heard that the the tube cradle can be a
distinguishing feature and there are several similar styles of equatorial
on scopes around the same aperture as this one. I'd say that the the mount itself
is pretty sturdy, setting circles after a bit of lubrication the slow motions work
fine it's pretty solid. Probably I don't really plan to use the mount at
the moment I'm going to put the scope on a more modern mount
because really this at this sort of focal length if I'm going to use the scope very much I know that I really
want to be able to to track to make it more enjoyable, it will get more use
so this is the case which is a bit of a beast
This one has foam inserts I've read that similar scopes sometimes are fitted with
wooden dividers within the case so maybe these foam or styrofoam inserts
will help to age or identify this scope and there are no labels I can find on
the case and typically this the scope came with a selection of three
eyepieces, porro prism, solar screen etc etc again none of those items have any
obvious clue to their manufacturer.
okay so some feedback on using the scope.
so i've mentioned i've put the tube onto a modern mount, i've got a Vixen Advanced
Polaris and so i think the Japanese theme seems to seems to suit, I think
it's a good looking good looking arrangement . A pair of 76-millimeter tube
rings do the job, easy to find and mounts very capable of carrying the
scope because despite the fact that it's over a metre long it's very light weight only
got a tube tube weight is two point six kilos so I guess why I like to look at
escapes to admire them probably like most of us do, the ones you like the
most are ones you use and the ones from which you get the best views certainly
that's how i feel about telescopes, so I've used the scope of a few occasions now and luckily
pleased to report that the optics seem very good so winter skies at the moment so
I had a very very clean split of the Trapezium for example very nicely
defined nebulosity in the Orion nebula. The double cluster in this scope is absolutely
fantastic you can just about fit both clusters in the field of view, and lovely colours
evident on some of the stars in those two clusters so fairly rudimentary star
test didn't really showing anything particular and certainly looking at bright
stars looking at the moon there isn't any real obvious sign of false colour so
it's early days in terms of using the scope but fingers crossed it's a good one but just
to come back the main purpose of the video is perhaps for you to help me
identify the origins of this particular telescope particularly how old it is
I don't know whether it's 50s 60s 70s so if anybody can perhaps give me a few
more clues I like to be able to pin down where it originally came from ok I hope
it's been interesting thanks for watching bye for now
you