Kvn-49 - UK Vintage Radio Repair and Restoration Discussion Forum

mrtmrtmrt · 7th Sep 2023, 4:01 pm

Hi everyone,

I'm interested in the old Soviet KVN-49 television, and have already seen Digger & Giuliuo's very useful information.

My interest is more in the optics of the lens, although the technical details of the CRT (and in particular the size limitations) are also fascinating.

Does anyone have any information about
- the dimensions of the lens?
- radius of curvature of the lens?
- how far it is set from the CRT/screen?

Would be very grateful if anyone has any information and would be happy to share it.

Ciao!

G6Tanuki · 7th Sep 2023, 6:49 pm

I rather doubt that those of us in the UK have ever come across the Soviet era TV you enquire about.

What line rate did it use? The UK used 405 and 625 lines for its analog TV with a 25Hz refresh rate.

FERNSEH · 7th Sep 2023, 9:34 pm

625 lines Russian Standard.

DFWB.

FERNSEH · 7th Sep 2023, 10:13 pm

From Wikipedia: https://en.wikipedia.org/wiki/KVN-49

From the Radiomuseum: https://www.radiomuseum.org/r/aleksandro_kvnkw_49.html

DFWB.

German Dalek · 12th Sep 2023, 7:07 am

Hello,

I have 2 of these fine sets (1 @ collection & 1 @ parts).

The set is unusual heavy because of the huge power transformer.

There were different feet for the magnifier available.
Mine is missing his feet.
The diameter is approx. 30 - 40 cms. It will be about 10 cms deep.
Like all eastern magnifiers is is made of perspex or something like that.

It is typical for eastern magnifiers, that they are liquid filled.
Oil or something else, which cannot freeze, water should work, too.

A typical distance between CRT and the back of the magnifier is about 10 cms or a little more.

The magnifier (aftermarket model? which was mounted on my Bush TV-1 is filled with a liquid, too.

I own an east-german and a czech TV receiver with liquid-filled lenses,
VEB / Rubens and Tesla 4000 series.
My french TV set, a L.M.T. with 7JP4, has a full-glass magnifier (heavy and clear).

My US-Pilot (3") has a full-perspex magnifier.

I have no informations, if my japanese 7" TV sets ever had a magnifier.
According to my original japanese literature there are any lenses shown.

Regards,
German Dalek

German Dalek · 12th Sep 2023, 7:14 am

Picture of the similiar czech magnifier:

7th Sep 2023, 4:01 pm	#1
mrtmrtmrt Diode Join Date: Sep 2023 Location: Florence, Italy Posts: 1	Kvn-49 Hi everyone, I'm interested in the old Soviet KVN-49 television, and have already seen Digger & Giuliuo's very useful information. My interest is more in the optics of the lens, although the technical details of the CRT (and in particular the size limitations) are also fascinating. Does anyone have any information about - the dimensions of the lens? - radius of curvature of the lens? - how far it is set from the CRT/screen? Would be very grateful if anyone has any information and would be happy to share it. Ciao!

7th Sep 2023, 6:49 pm	#2
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,465	Re: Kvn-49 I rather doubt that those of us in the UK have ever come across the Soviet era TV you enquire about. What line rate did it use? The UK used 405 and 625 lines for its analog TV with a 25Hz refresh rate. __________________ I played a blank tape at full volume. The mime-artiste who lives next door complained.

7th Sep 2023, 9:34 pm	#3
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,377	Re: Kvn-49 625 lines Russian Standard. DFWB.

7th Sep 2023, 10:13 pm	#4
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,377	Re: Kvn-49 From Wikipedia: https://en.wikipedia.org/wiki/KVN-49 From the Radiomuseum: https://www.radiomuseum.org/r/aleksandro_kvnkw_49.html DFWB.

12th Sep 2023, 7:07 am	#5
German Dalek Hexode Join Date: Jan 2011 Location: Düsseldorf, Germany. Posts: 352	Re: Kvn-49 Hello, I have 2 of these fine sets (1 @ collection & 1 @ parts). The set is unusual heavy because of the huge power transformer. There were different feet for the magnifier available. Mine is missing his feet. The diameter is approx. 30 - 40 cms. It will be about 10 cms deep. Like all eastern magnifiers is is made of perspex or something like that. It is typical for eastern magnifiers, that they are liquid filled. Oil or something else, which cannot freeze, water should work, too. A typical distance between CRT and the back of the magnifier is about 10 cms or a little more. The magnifier (aftermarket model? which was mounted on my Bush TV-1 is filled with a liquid, too. I own an east-german and a czech TV receiver with liquid-filled lenses, VEB / Rubens and Tesla 4000 series. My french TV set, a L.M.T. with 7JP4, has a full-glass magnifier (heavy and clear). My US-Pilot (3") has a full-perspex magnifier. I have no informations, if my japanese 7" TV sets ever had a magnifier. According to my original japanese literature there are any lenses shown. Regards, German Dalek __________________ And now something completly different: MARC BOLAN, he was/is the real king of Pop Music!

12th Sep 2023, 7:14 am	#6
German Dalek Hexode Join Date: Jan 2011 Location: Düsseldorf, Germany. Posts: 352	Re: Kvn-49 Picture of the similiar czech magnifier: Attached Thumbnails $Click image for larger version Name: ImageFile_{4C94FFE4-95F9-4C98-A631-451902108604}1.jpg Views: 48 Size: 75.7 KB ID: 284836$ __________________ And now something completly different: MARC BOLAN, he was/is the real king of Pop Music!