Have acquired a Tal1, in need of advice

[BackgroundWay]

Hi everyone, I am completely new to telescopes and have just acquired a Tal1 telescope. The person I bought it from said that it was a working but having looked at it it is missing the plug in lead and an eyepiece.
 

I’m wondering if anyone who has experience with this telescope could help me in figuring out how to get it in working order. My partner thinks the lead is just a cable lead but we don’t know for sure, and I’m not sure what size eyepieces it needs. The person who sold it to me said it was a Tal1, but the scope belonged to their daughter and they couldn’t tell me anymore about it and there is no identifying information on the scope.

 

Any help would be greatly appreciated!
 

 

[Carbon Brush]

Hello and welcome to SGL.

Yes a TAL scope. No there are no leads, it being completely manual operation.
I used to own one.

These were very well engineered scopes and mounts, with good optics.
But today, it all depends on if it has been looked after.

Two suggestions to get you started.
First is look at the primary mirror condition, take a photo.
Second measure the diameter of the eyepiece tube. hopefully it is 1.25".
Though some early TAL scopes used a different size.

If you include your approximate location in your header information, you may get a local offer of help.

 

[Astrobits]

The early TAL's had a 32mm eyepiece dia but I believe that they changed to the 31.7mm ( 1 1/4" ) on later production. Not much difference but standard eyepieces will be very loose and not sit square in a 32mm hole. Some TAL's had a motor drive that was housed in a black box which yours does not have.

Once upon a time I inquired with the local importer of these scopes about spare eyepieces for use on other scopes. The response that came from Russia was that

" our telescopes come with eyepieces, why would you want more"

Nigel

 

[Peter Drew]

I have two of these and they are excellent all round, optically and mechanically.  A little on the heavy side for the aperture.  As mentioned, check the eyepiece fit size, if the 32mm then you can wrap the current 31.7" eyepieces with a bit of tape.  The manual controls on mine are short rigid shafts with knurled knobs.     🙂

[BackgroundWay]

Thank you so much for the help so far 😊

 

I’ve had a closer look and this is what I have found, I’ve included some pictures below.
 

The primary mirror looks like it has some scratches on it, two of which are fairly big chips. 
 

I’ve tried to measure the eyepiece and I think it is 25mm. 
 

There is a plug connector to it, does anyone know what that is for?

 

Thanks again, I bought this for my partner for his birthday and I was stressing that I had unknowingly bought a big and very heavy piece of junk. 
 

[Carbon Brush]

I wouldn't worry about the mirror for now. It is good enough to provide views.
Cleaning it is a project for another time.

The eyepiece barrel size has me puzzled.
Mine had a 1.25" (31.7mm) barrel, which is used on all proper scopes - but not the toys sold by the likes of amazon.
@Astrobits mentioned 32mm on some early scopes. @Peter Drew gives an easy fix. Thank you both.
There is, on some old scopes a 0.965"/24.5mm barrel size. also known as the 'Japanese inch'🤣.
I would be surprised to find one of these on a TAL.
Perhaps photos of the eyepiece area?

The socket on the side would connect to a mains transformer in a metal box, stepping down to 12V.
It turns the scope every 24 hours so the scope will follow an object as it moves across the sky.
I won't give you the full explanation just now - it is somewhat lengthy.
If you don't have this part, don't worry. Just move the scope manually.

Get hold of an eyepiece to fit the tube. I think 25mm or thereabouts focal length is a good starting point.
Look at easy objects first, like the moon, or Orion.

The scope is not junk. It is quite probably recoverable - dpending on a proper look at the mirror.
Even if the scope was scrapped, the pillar is really solid.
Much better than the wobbly things fitted to a lot of the basic scopes nowadays. 

Keep asking the questions.

David.

[Siegfried1969]

Hello,

I acquired my TAL-1 in 2005 and it is still my main telescope. Never used anything else in all these years. They are of excellent optical quality and the mechanics and build are far better than the telescopes they make today. I remember this TAL came in two versions. A manual and a motorized version. Mine is a manual and maybe you can find the user manual for the motorized version still somewhere online. So as I do not have experienced with the motor and its connection, I know the mechanical parts of this telescope very well. Last year, I have completely disassembled mine, cleaned it, regreased it and put it back together. That is what I all have done:

• full disassemble of the mirror cell, clean all the rust out with vinegar and sent both primary and secondary mirror to Orion Optics UK for recoating. Their service is very good and price was reasonable but as I am in Belgium transport + taxes were high. If you are in the UK you won't have this issue. It takes them around a week to recoat.
• I flocked the tube with black velour I bought from Teleskop Service
• I added on a rigel finder
• I replaced the straight TAL 6x30 finder with a right angle 7x50 finder. Honestly this finder is the weakest part of the telescope. Although of good optical quality, this finder is nearly impossible to use as you have to put your head in all kinds of positions to look through it. As I am wearing glasses, finding objects was impossible
• I tool the mount apart and degreased it with soda dissolved in hot water
• Put everything back together and regreased everything

If you want a great guide on how to do everything, there is no better than the guide from Astrobaby: TAL-1 Telescope Restoration Project (astro-baby.com) 

I used this guide as well to disassemble everything. The mirror cell is a bit tricky but not impossible. You have to be very careful if you put the mirror back in and screw the ring back on. Due to the pressure, the mirror start to turn in its cell and will scratch on the side where the 3 holder points are. I got this and my newly coated mirror is scratched along the edge. So I am loosing like 1-2 mm of aperture.

Now the telescope is back operational and with the new finder, its a joy to use and to find objects. The image is also brighter and detail like on the moon is unbelievable. I send you here a pic of my scope in the current state + the original delivery set list so you can check if you have all the accessories. If further questions pls ask !

Good luck !

siegfried

[markse68]

Hi @BackgroundWay, add a pic of the focuser and we should be able to identify if it’s the older 32mm or the 1.25” type from what it looks like. If it’s 1.25” you are in luck as any cheap plossl you can find on ebay will get you started and as Peter said you can wrap sellotape around the barrel if you have the older 32mm focuser. The 32mm eyepieces do turn up fairly regularly on ebay and other sites and the 25mm plossl is (was) very nice. I think they were originally supplied with the 25mm and a 15 or 10mm and a 2x or 3x barlow lens for increasing the magnification. The finders are lovely too

As you don’t have the transformer, you could remove the motor from inside the housing which will make the manual RA adjustment easier- otherwise you’ll be back driving the motor which adds drag. It’ll work fine manually even if you don’t though. You have the advantage of 360deg RA adjustment with a clutch system for coarse alignment which the unmotorised mount doesn’t have

They’re lovely scopes as others have said- if the mirrors are in good condition, definitely not junk. Check out @Siegfried1969’s sketches in the sketching section here to get an idea of what they are capable of- it’s really amazing! 

I’m using a different Tal scope currently as my main visual scope and love it- they made fine scopes for sure.

@Siegfried1969, good to hear you got your mirror recoated- has it made a huge difference? I’m contemplating getting my 150p recoated by Orion too

Mark

 

Edited March 11, 2023 by markse68

[markse68]

@BackgroundWay there’s a Tal 25mm plossl (1.25”) in the classifieds just appeared 

Mark

edit- sorry i don’t think you have access yet 

Edited March 11, 2023 by markse68