45 replies to this topic

[lumière tangible]

Hi everybody,

 

So here is my new acquisition: a Starliner 8" f/8 (i've been told by the seller although there is no branding on the tube) and an Astrola mount.

 

I removed the mirror to clean it. On the back is written: 7L. 64" Meridian.  

 

Anyone knows what 7L. means?  I search for Meridian company but didn't find a lot..where they making mirrors, complete telescopes?

 

Looking forward to try it!

 

Thanks 

Eric

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[CHASLX200]

The top end ring looks like the same stuff Cave used in the mid and later 70's. But Starliner never used rotating rings. Always clamp style rings, I don't see it being a Starliner OTA. Maybe the mirror is.

[ngc7319_20]

Could  "7L." be "FL."  ?

[lumière tangible]

Could  "7L." be "FL."  ?

Haha, yes, that would make sens! 

[John Rose]

Perhaps "Meridian" is the name of the optician?  I have a Parks mirror with the focal length and opticians name on the back.  Starliner may have bought their tubes from the same source (Parks?) as Cave.  Then they would fit the Cave rings.

[astrotabby]

Custom mirror maker back in the mid-1960's.  Forget his name.  He advertised in Sky&Tel.  I had one of his 8" f/6 mirrors for several years in a homebuilt scope.  To this day, I wish I hadn't sold it.  Hope that helps.

Chris

[lumière tangible]

The top end ring looks like the same stuff Cave used in the mid and later 70's. But Starliner never used rotating rings. Always clamp style rings, I don't see it being a Starliner OTA. Maybe the mirror is.

Thanks for those infos!

[lumière tangible]

Custom mirror maker back in the mid-1960's.  Forget his name.  He advertised in Sky&Tel.  I had one of his 8" f/6 mirrors for several years in a homebuilt scope.  To this day, I wish I hadn't sold it.  Hope that helps.

Chris

Thanks! Yes it helps.  I'm pretty new to astronomy in general and those classic telescopes in particular (but i think i'm getting hooked on both..) so any infos are very welcome and i find a lot of interesting stuff on this amazing forum!

 

I just cleaned the mirrors, put them back and collimated it.  Now i'm waiting for the rain to stop.

 

Eric

[lumière tangible]

The top end ring looks like the same stuff Cave used in the mid and later 70's. But Starliner never used rotating rings. Always clamp style rings, I don't see it being a Starliner OTA. Maybe the mirror is.

Could it be homemade from different sources parts.  If so, is there any way to tell?

[lumière tangible]

Perhaps "Meridian" is the name of the optician?  I have a Parks mirror with the focal length and opticians name on the back.  Starliner may have bought their tubes from the same source (Parks?) as Cave.  Then they would fit the Cave rings.

Thanks, i'll look that up.

[apfever]

It is so hard to tell if a previous owner has changed something or swapped classic parts. 

The smaller cage assembly piggy backed on the main OTA looks like two I have on Optical Craftsmen OTA.

I didn't try examining the comparison to nuts and bolts. The first one is on a 10" ANRA (O.C.), the second is from a 12.5" O.C.

 

Side by side the cages are different.  

 

My Star-Liner 8" F8 OTA has a Pancro sticker 1966. The primary has some red writing on it. I've never taken the cell/primary out. The end rings are different. The primary cell is noticeably higher up in the tube the same amount which is a dead match and stands out looking around at other OTA. My focuser is a Sky Micro.   This is a little funky for comparisons but my spider bolts are bigger and the cell bolts are smaller and appear to be the same acorn type up top and straight slot on the bottom.  

 

OP's pictures are lacking at this point for better details. 

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Edited by apfever, 21 October 2023 - 08:25 PM.

[lumière tangible]

It is so hard to tell if a previous owner has changed something or swapped classic parts. 

The smaller cage assembly piggy backed on the main OTA looks like two I have on Optical Craftsmen OTA.

I didn't try examining the comparison to nuts and bolts. The first one is on a 10" ANRA (O.C.), the second is from a 12.5" O.C.

 

Side by side the cages are different.  

 

My Star-Liner 8" F8 OTA has a Pancro sticker 1966. The primary has some red writing on it. I've never taken the cell/primary out. The end rings are different. The primary cell is noticeably higher up in the tube the same amount which is a dead match and stands out looking around at other OTA. My focuser is a Sky Micro.   This is a little funky for comparisons but my spider bolts are bigger and the cell bolts are smaller and appear to be the same acorn type up top and straight slot on the bottom.  

 

OP's pictures are lacking at this point for better details. 

The small cage is different.  There is no knobs, only flippable bolts with butterfly nuts where it clamps.

 

There is two holes set for the primary.  When i got it, the primary was install on the upper holes.

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[CHASLX200]

Thanks for those infos!

It is all Cave. Maybe the mirror is the only thing Starliner.

[CHASLX200]

Could it be homemade from different sources parts.  If so, is there any way to tell?

Not really anyway to know. Tube is a Parks as many scope makers used them. Rings look Cave and mount is Cave and the end rings look Cave,

[apfever]

The small cages are too different. I'm disregarding the concept of Optical Craftsmen. It's not a match. 

 

Chas repeated twice in the same entry that your end rings look Cave so I closely looked at mine. They look identical down to the little little things. 

 

Comparison to my Star-Liner 8" F7.3 (measured) still varies a lot. Heck, I have reason to believe my StarLiner is possibly ATM (home made). I pulled my OTA for more than comparing nuts and bolts which is kind of a brain frt thing.  The primary cell and secondary system are biggies. Here are the ones on my StarLiner. Showing your cell and secondary will go a long way to helping you identify things. Maybe me too. 

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Edited by apfever, 22 October 2023 - 10:39 AM.

[deSitter]

The small cages are too different. I'm disregarding the concept of Optical Craftsmen. It's not a match. 

 

Chas repeated twice in the same entry that your end rings look Cave so I closely looked at mine. They look identical down to the little little things. 

 

Comparison to my Star-Liner 8" F7.3 (measured) still varies a lot. Heck, I have reason to believe my StarLiner is possibly ATM (home made). I pulled my OTA for more than comparing nuts and bolts which is kind of a brain frt thing.  The primary cell and secondary system are biggies. Here are the ones on my StarLiner. Showing those parts will go a long way to helping you identify things. Maybe me too. 

That is a sweet cell with adjustment for centering provided. SO important for good collimation to get the tube and the mirror cells to cooperate!

 

-drl

[apfever]

That is a sweet cell with adjustment for centering provided. SO important for good collimation to get the tube and the mirror cells to cooperate!

 

-drl

Handy for sure but not critical. More just handy. As long as the axis of the focuser and primary are aligned through the secondary, you are collimated. It is nice if the tube is not so offset or tilted that it severely vignettes the the field of view. This why centering the primary and secondary, and squaring the focuser are the main primary guides of the build. Sometimes that is not possible like a secondary on a stalk that can't reach the center of the tube. Yechh, then you have a tilted tube relative to the optical axis, a focuser shimmed out of square to the tilted tube, and so on.   

 

Here's a wild one I haven't thought much of. The secondary is just a flat plane. You can place the secondary anywhere on that plane you want as long as the axis of the focuser and axis of the primary coincide reflecting off the secondary. You are collimated. If the secondary is too far offset from center of the optical axis reflection, then the secondary can be a source of vignetting. I haven't thought much about a secondary as a source of major vignetting but it is possible in a perfectly collimated system. 

 

Collimation: alignment of the optical axis of your eyepiece (focuser if it moves) and optical axis of your objective. It is nice if the rest is centered and pretty enough to not vignette the view.  

Edited by apfever, 22 October 2023 - 11:33 AM.

[icomet]

On the tube end rings, Cave made 3 types, II've had all 3. Those look to be the cast aluminum , "push on" type.

 

Can you maybe snap a couple of more images, trying to get them in more light?   

 

I'll wade in on the rest later. 

 

Clear Skies. 

[John Rose]

Parks also sold the end rings for their tubes. They also sold rotating ring assemblies. Although the one I have is not quite the same as the one Cave I have. The present rotatting ring assembly could have come with the mount. I would expect to see a Cave name plate screwed to the tube near the focuser. Or two empty holes. But then maybe they had some name plates that glued on? Then there would be no trace of it if the glue residue was removed. The extra holes in the tube for the mirror mount are for visual use, the ones closest to the end of the tube. And for astrophotography, the ones further up the tube. Purests might actually want to change the secondary to reduce the central obstruction when using the scope visually. The 10" F6 Cave I have has the two sets of holes and a 3.5" secondary. It has a custom made Off Axis guider assembly.  I suspect Eric's scope may be home made from commercial parts.

[lumière tangible]

The small cages are too different. I'm disregarding the concept of Optical Craftsmen. It's not a match. 

 

Chas repeated twice in the same entry that your end rings look Cave so I closely looked at mine. They look identical down to the little little things. 

 

Comparison to my Star-Liner 8" F7.3 (measured) still varies a lot. Heck, I have reason to believe my StarLiner is possibly ATM (home made). I pulled my OTA for more than comparing nuts and bolts which is kind of a brain frt thing.  The primary cell and secondary system are biggies. Here are the ones on my StarLiner. Showing your cell and secondary will go a long way to helping you identify things. Maybe me too. 

Cell and secondary look identical to yours.

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[deSitter]

Handy for sure but not critical. More just handy. As long as the axis of the focuser and primary are aligned through the secondary, you are collimated. It is nice if the tube is not so offset or tilted that it severely vignettes the the field of view. This why centering the primary and secondary, and squaring the focuser are the main primary guides of the build. Sometimes that is not possible like a secondary on a stalk that can't reach the center of the tube. Yechh, then you have a tilted tube relative to the optical axis, a focuser shimmed out of square to the tilted tube, and so on.   

 

Here's a wild one I haven't thought much of. The secondary is just a flat plane. You can place the secondary anywhere on that plane you want as long as the axis of the focuser and axis of the primary coincide reflecting off the secondary. You are collimated. If the secondary is too far offset from center of the optical axis reflection, then the secondary can be a source of vignetting. I haven't thought much about a secondary as a source of major vignetting but it is possible in a perfectly collimated system. 

 

Collimation: alignment of the optical axis of your eyepiece (focuser if it moves) and optical axis of your objective. It is nice if the rest is centered and pretty enough to not vignette the view.  

Not just handy. I know you can have a Newt that is skewed all over the place as long as you are looking down the mirror's center line. But the real world is both mechanical and optical, and the most important thing in any telescope is that the mechanical and the optical cooperate. Sometimes there is no choice, but when there is a choice, why not do it right from the start?

 

(back to the thread)

 

-drl

[lumière tangible]

On the tube end rings, Cave made 3 types, II've had all 3. Those look to be the cast aluminum , "push on" type.

 

Can you maybe snap a couple of more images, trying to get them in more light?   

 

I'll wade in on the rest later. 

 

Clear Skies. 

Here they are, push on aluminum end rings.

 

Thanks!

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[lumière tangible]

Parks also sold the end rings for their tubes. They also sold rotating ring assemblies. Although the one I have is not quite the same as the one Cave I have. The present rotatting ring assembly could have come with the mount. I would expect to see a Cave name plate screwed to the tube near the focuser. Or two empty holes. But then maybe they had some name plates that glued on? Then there would be no trace of it if the glue residue was removed. The extra holes in the tube for the mirror mount are for visual use, the ones closest to the end of the tube. And for astrophotography, the ones further up the tube. Purests might actually want to change the secondary to reduce the central obstruction when using the scope visually. The 10" F6 Cave I have has the two sets of holes and a 3.5" secondary. It has a custom made Off Axis guider assembly.  I suspect Eric's scope may be home made from commercial parts.

There is no evidences of a name plate (holes, glue or discoloration in the finish) that i can see.  As you say, maybe the scope is homemade and have been matched with the Cave mount and rings.

 

Thanks!

Eric

[deSitter]

There is no evidences of a name plate (holes, glue or discoloration in the finish) that i can see.  As you say, maybe the scope is homemade and have been matched with the Cave mount and rings.

 

Thanks!

Eric

Yes could be. I think it was possible to buy a tube with rings already fitted, right Chas?

 

-drl

[CHASLX200]

That is a sweet cell with adjustment for centering provided. SO important for good collimation to get the tube and the mirror cells to cooperate!

 

-drl

I got one of their adjusta cells back in 1988 for a Edmund 8" F/8 i redid.