Yesteryear telescope query

[Atmos (Colin)]

Hey all!

I'm putting this out there with currently very limited information and no images but I will get some soon.
My wifes grandmothers late husband 20 years ago drove down from Wangaratta to Melbourne and purchased a telescope. I believe it to be a 4" F/12 but I won't be able to really confirm anything until I get up there and have a closer look. I saw it once briefly in the corner of a room a few years ago.

The story is that he came down to Melbourne and purchased it from someone that made the telescope; ground the lens' and everything. I do remember looking at the lens cell briefly a few years ago and my thought is that it looked manufactured but had no company or persons name to give information as to where it's from. From memory it kinda reminded me of an older Sky Watcher achromat.

No sure if it is a doublet. Planning on taking a red laser with me to see if I can count lens grouping reflections. Assume that's the way Red laser and torches is what I've got to use.

My query is whether anyone knows of someone in Melbourne that built refractors back around the year 2000. Believe it may have been paired with an EQ2.

[Rainmaker (Matt)]

Sounds like something Barry Adcock might have made, his OTAs looked a bit like the older SWs.
If it is an Adcock then David Booth might be able to put you in touch with Barry. I last spoke with Barry a few years ago when I was considering one of his creations, he also offered to test a CFF scope for a friend.

[dannat (Daniel)]

Cloin posy some pics & I can ask barry for you - he lives near where i work?

[bojan]

Green laser may be better...

[Eldest_Sibling (Alan)]

At /12, it should be a doublet, and achromatic, but no matter. The higher the focal-ratio, the better whilst observing brighter, tighter objects, like the planets, and stars, single and double. It's good, that, at f/12, rather than a commercial instrument at f/10.

To improve contrast, to perhaps rival that as seen through apochromats, also to eliminate ghostings, blacken, and perhaps flock, the telescope, from fore to aft, beginning with the doublet and in making it "invisible"...



The spacers, if not a cemented affair, must be noted whilst separating the lens-elements, and replaced if needed. The order of an achromatic-doublet...



There should not be anything reflective within the lens-cell, the optical-tube, the inner areas of the focusser's housing, etc; only that of deepest, ultra-flat black...





Congratulations on the acquisition.

[Atmos (Colin)]

Hello everyone,

Thanks for the responses so far, I have finally got my hands on it for a proper look and I've got some photos.
I've taken some measurements and I believe it to be a 3" F/15-18. My first impression a couple of years ago was off by an inch! I've measured from the front of the objective to the rear of the focuser and it comes in at 45". Once the focuser is racked out a little and a diagonal is added it could push it closer to the F/18.

Has a sticker on the bottom that says "Introductory & Hand Crafted Telescopes" and then the mobile number of Cris Ellis of Astronomy Alive. The telescope is all black, has a finder scope bolted onto it and has 3 collimation bolts for the objective.

From what Cris has told me in the past he designs optical systems but I don't think he's ever built a refractor so I am still wondering if it could be something from Barry.
The image Matt posted is of a white telescope so I'm not sure if most of what he did was white.

[Eldest_Sibling (Alan)]

Originally Posted by Atmos

Hello everyone,

Thanks for the responses so far, I have finally got my hands on it for a proper look and I've got some photos.
I've taken some measurements and I believe it to be a 3" F/15-18. My first impression a couple of years ago was off by an inch! I've measured from the front of the objective to the rear of the focuser and it comes in at 45". Once the focuser is racked out a little and a diagonal is added it could push it closer to the F/18.

Has a sticker on the bottom that says "Introductory & Hand Crafted Telescopes" and then the mobile number of Cris Ellis of Astronomy Alive. The telescope is all black, has a finder scope bolted onto it and has 3 collimation bolts for the objective.

From what Cris has told me in the past he designs optical systems but I don't think he's ever built a refractor so I am still wondering if it could be something from Barry.
The image Matt posted is of a white telescope so I'm not sure if most of what he did was white.

Within the second image, is the lens cell there, the housing, with a hex screw evident, is it of plastic? Also, is the focusser housing and draw-tube(third image) of plastic?

[Atmos (Colin)]

Originally Posted by Eldest_Sibling

Within the second image, is the lens cell there, the housing, with a hex screw evident, is it of plastic? Also, is the focusser housing and draw-tube(third image) of plastic?

Hey Alan,

Just had another look, the hex screws I don't believe are for collimation as they sit a ways below the lens cell. The whole section around the lens cell is plastic. I believe the lens cell (plastic) screws into that plastic end section (plastic) which is bolted onto the metal tube with 3 hex bolts.

I haven't been game to unscrew anything yet.

[Eldest_Sibling (Alan)]

Originally Posted by Atmos

Hey Alan,

Just had another look, the hex screws I don't believe are for collimation as they sit a ways below the lens cell. The whole section around the lens cell is plastic. I believe the lens cell (plastic) screws into that plastic end section (plastic) which is bolted onto the metal tube with 3 hex bolts.

I haven't been game to unscrew anything yet.

Hi Colin,

Yes, those are simply for securing the lens-cell to the optical-tube. I usually see cross-head screws for that. The heads of screws for collimating a refractor are usually forward-facing. I have only one refractor with that type...

https://i.imgur.com/2naBDnI.jpg

I am surprised, however, that hex-screws were used. That's usually indicative of higher quality. Also, within your first image, the three shiny spacers for the doublet-lens are reminding of the refractors of Vixen of Japan, although they have outsourced to China over the years; also, the bluish sheen of the doublet.

Getting back to the focusser, at the rear, it appears to be of metal.

In any event, an unobstructed 3" of aperture is worth the while, especially at a longer focal-length as that one. My congratulations still holds.