KRONOS 3T-65

[ToTo123]

Hi Everyone,

 

Thank you for the warm welcome. As you can guess I'm new to this. I have just purchased a Kronos 3T- 65 telescope for very little money. I purchased it so my daughter could gaze at the skies at night as she has a few issues going out during the day. The telescope is in great condition but there is two items missing from the telescope. The Barlow lens is missing and a sleeve extender. At the moment I only have the eye piece. I have looked all over the net trying to find the company who makes these telescopes. They look very similar to the TAL Alcor. I was wandering is there any alternative Barlow lenses, sleeves and accessories I can purchase for the telescope. I did not want to purchase a bigger scope as I have not got the room for one. Any information would be fantastic.

 

Regards Anthony

 

[ronin]

If the eyepiece is a 1.25" fitting then any 1.25" barlow will fit - and there are lots of them, 1.25" is the sort of standard size.

If the eyepiece is 0.965" then a bit more of a problem.

First question is do you want a barlow?

It may be easier or bwetter to get say 2 additional eyepieces.

Few questions: What is the focal length?

Does the present eyepiece work OK? As in is an extension tube necessary.

[kalasinman]

I was looking at Barlows and EPs to help someone and was surprised that modestly good EPs are cheaper than cheap Barlows. Less glass is better?

[ToTo123]

Hi All
 
Thank you for the prompt reply. I have this information can you make any sense of it and tell me in the simplest way. are the telescopes any good I only wanted a simple one as this was real cheap. £15
regards Anthony

[ronin]

The diagram although well done is a bit simplistic or idealised,

Usually the barlow is a lens in a tube, you drop the barlow into the focuser, then drop the eyepiece into the barlow. then stick your eye at the eyepiece.

Or you forget the barlow and drop the eyepiece into the focuser then stick your eye at the eyepiece.

In effect the barlow is optional, that diagram does not quite imply that, or at least does not make it obvious.

The main question is the necessity or otherwise of the small extension bit - yes they are mentioned on the Tal 65's as "plastic eyepiece spacer", so would seem to be an integral item.

As mentioned:- does the scope bring say the moon to focus with just the eyepiece in the focuser?

Also measure the eyepiece base bit, if it is 1" then it is a 0,965" EP, if 1.25" the the bigger and easier ones.

If 0.965" then I suggest that you look at Joy's Optics on ebay and buy the set of four 0.965" eyepiece they have advertised at £15. They will not be great eyepieces - likely simple Huygens - but then you have 4 eyepieces to play around with that fit the scope.

If the moon cannot be brought to a decent image as in remains out of focus then it may be that the spacer is required, that is more of a problem.

Fixable I suspect but slightly more involved. May well rest on who you know.

At this time I would guess that getting a 0.965 to 1.25 adaptor and a set of 1.25 eyepieces is simply impractical owing to the cost of the scope.

It seems to hinge on whether or not the eyepiece will give a focused object.

P.S. Seems somewhat of a rare beastie, how many pages in the "manual" ? There are websites that would I suspect appreciate a set of images of the whole thing for records.

[ToTo123]

Hi

I found this part of the manual on the internet. I have tried to find more but there is no information at all. Just to mention the eye piece is screw threaded on a internal flange would the spacer be the same. the mirrors and optics are very clean. I have only tried it in a testing capacity. I focused the scope to look at some roof tiles they focused in ok.

regards Anthony

[ronin]

That sounds like the eyepiece is threaded and so screws into the focuser - meaning only "their" eyepieces will work in it.

I see on the first set of images no sign of a screw to secure the eyepiece, although it may be out of sight.

Does the threaded bit on the eyepiece unscrew?

My thought is that if it unscrews and then if the lower section of a normal 0.965" eyepiece unscrews then you can move the threaded bit from eyepiece to eyepiece to use them. Very long winded way but nothing else comes to mind.

I notice that the manual only refers to 1 eyepiece. Makes me think that the user was only intended to use that one eyepiece and to alter magnification the barlow went in one way or the other maybe with or without the spacer. The wording also would seem to support that idea.

I get the feeling that to use other eyepieces then you may have to know somone with a lathe to turn an adaptor of some sort. Likely not complicated but necessary.

[ToTo123]

Yes the eye piece unscrews from the focuser. the focuser has a r=f27.5* with a thread inside the eye piece has a lip then a step down threaded screw.

[ronin]

Without seeing the scope and everything I am getting more convinced that it operates as :

1: Screw eyepiece in, focus on object and it delivers 38.6x magnifiation.

2: Screw barlow in one way and then screw eyepiece into barlow and it delivers 80x magnification.

3: Screw the barlow in the other way round, screw in spacer, screw in eyepiece and it delivers 127.5x magnification.

Having said that, read your last post and looked at the manual P2 - does the focuser say "r=f27.5*" or is it a bit in the focuser that says r=f27.5* and if it is a bit in it then does it unscrew ?

Just the text in P2 Delivery Set may imply that whatever says r=f27.5* is actually a screw in bit.

Reading P2 the Specification and the Delivery Set seem a little at odds with each other, as in they do not quite match.

I wonder if the barlow, or a barlow, is actually in the focuser at present and you do not realise.

Do not go forcing anything to move.

[ToTo123]

Yes the eye piece unscrews from the focuser. the focuser has stamped to it r=f27.5*.....  the eye piece has a lip then a step down threaded screw. that fits and screws inside the focuser

[ToTo123]

I cant remove the focuser I thought it may have unscrewed but it does not seem too. I will have a go at removing it. I'm hoping myself that this could be the missing piece 

[ToTo123]

Hey Ronin

the part in focuser is threaded and does remove, I know have two parts to the telescope. I think it might be the barlow. 

regards Anthony

[ronin]

Without seeing the scope in detail I am not sure how much advancement that makes.

If both ends of the barlow are threaded then I suspect is can go in either way and so deliver the 2 different barlowing factors, likely 2x and 3x, but could be anything.

For the higher one you likely need the missing spacer, barlows tend to push the focus out, and I guess the lower factor uses the barlow tube itself whereas the higher one would need the spacer.

Other question is does the eyepiece screw directly into where the "barlow" comes out of (focuser).

If so then I suspect that that means you can use eyepiece alone, or barlow and eyepiece.

If you ever fanicied being really mad I would half suggest getting something made to screw or go into the focuser to hold a standard 1.25" eyepiece. You would need to know where the focal plane is to sit the eyepiece at the right position.

[ToTo123]

yes the eye piece screws directly into the focuser. I tried it yesterday. picked a pint at the bottom of the street and focused in a lot more sharper and detail.

regards Anthony

[ToTo123]

if I was to get something made to screw or go into the focuser to hold a standard 1.25" eyepieces. How would I  know where the focal plane is to sit in the eyepiece at the right position. can you give me any suggestions.

regards Anthony

[ToTo123]

I tested the scope out last night. I'm really new to this and we looked at a bright star to the right of the horizon at 1 or 2 o' clock position  it was very blurred l in the with the eye piece and Barlow in the focuser. when the eye piece was places in the focuser on it own the star or planet came into view. I don't know what it was I could not see any detail as it was a little small. if you looked at the sky from where we were looking to the left is the moon then another star then....   the one I was looking at. So there was three objects in the sky its nice to know it works.

kind regards Anthony

[ToTo123]

Hi All

 

can anyone please give advice about these parts.. how long would the extender be? as you can see they all screw into the focuser. and if I wanted to get an extender made for other eye pieces what's the focal plane?

 

regards Anthony

 

 

[ToTo123]

anyone wish to add how i can get the extender