[Arran]

Mike and Peter may be interested in this, I obviously can't understand what this gentleman is saying but I think I understand the theory of changing capacitor values in the local oscillator tank circuit for FM, though how well this works with the stock coils I don't know. I am not about to try this on either of my USSR built sets, as I can recall when I had the Chaika running it would pick up the audio for one of the local, over the air, analog TV channels in the Edmonton area, but since I have enough sets that have the 88-108 MC FM band on them there isn't any reason to modify the Soviet ones. By the way, did they have to pay royalties to Armstrong's estate when the started building FM sets in the USSR?  
  I am actually surprised how many Y.T channels involve radio and TV restoration in that part of the world, and they apparently have a lot of views. I had assumed that they were still broadcasting on the Soviet era FM band but maybe the selection isn't as good?
Regards
Arran


https://www.youtube.com/watch?v=EcAhdGJHKN8

[morzh]

I doubt they paid or pay any royalties to anyone for anything.
RCA caught them red-handed, so they caved in - at the time they needed US help in building the industry.
This said, even though the first 1kW at 46.5MHz UKV (FM) station was built in 1946, im earnest they started using it in 50s. They had their own group of engineers who experimengted with it since 1920s.
And when the real FM went into effect, in 1990s, well...patents do not last long.

[RadioSvit]

Hello Arran. Thanks for the link. Installing an FM converter rarely brings the maximum result. Harmonics appear from the interaction of different frequencies. Therefore, I chose another option, reduced the inductance of the heterodyne and input circuits and selected the capacitance of the equalization capacitors. It takes much more time, but the result is much better.

[Arran]

Peter;
  I believe that one of the sets he did this to was a Belarus 57, which I would not alter if I had one, it looks like the scale for FM was very small, in fact it took me a while of watching videos with them to notice that the FM scale was not in parallel with the SW, LW, and MW scales but ran vertically along one side. I was disappointed that nobody seemed interested in demonstrating anything other then FM reception given that they have a tuned RF amplifier stage, so would probably perform well on shortwave. I would think that a low powered RF transmitter tuned to the 65.7-76 mc/mhz OIRT FM band would probably work just as well. As I mentioned I remembered that the FM band on the Chaika set would pick up the audio channel of one or more analog TV station when I was in Edmonton, Alberta, and the tuning was somewhat broad. One day I will have to restore the Chaika, I can't really remember why I stopped using it, if the date codes are correct it was manufactured in 1966 or 1967, the only alteration I made was in connecting the speakers so they could be unplugged to pull the chassis out. 
Regards
Arran

[RadioSvit]

Aran, if you feel nostalgic for Chaika, I can give it to you. I have such a radio. But considering the fact that there is currently no economical delivery from Ukraine to the USA, the cost of delivery can be quite high.

[Arran]

Peter;
I still have the Chaika, it's pretty much all there, but probably needs the capacitors replaced by now, and possibly the phonograph cartridge. It's sort of an oddity in that one corner of the dial, written in English is "Made in USSR Sample" so it may have been a demonstration model for a trade fair, or may have been on display at Expo 67 in Montreal in the USSR pavilion, but I have no proof of either other then the age of the set. One issue that it does have is that the mechanism that holds the lid up for the phonograph section is broken, and always has been since i've owned it.
The other Soviet radio I have is the Octava, which has issues, no speakers, the tuning capacitor was seized up, and the dial scale had peeling paint. I really need to pull that one out of storage and have a look at it, I haven't looked at in 25 year or more. An odd coincidence with the Octava is that the factory that produced it was apparent called ZIL, like the factory that manufactured Soviet era limousines and trucks.
Regards
Arran

[RadioSvit]

I have all these spare parts for Octavia, Arran. I don't remember exactly, but it seems that there is also a scale. If you need them, I can give them to you for free. So you only pay for the delivery. Delivery of small parcels from Ukraine is cheap.