• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

FM tuner finished

Here we go all working - results are very good sensitive and selective. I can post the kicad stuff and code and alignment if interested.
 

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Good stuff....I also have a home-made decades old FM tuner with ECC88´s, but attempted to change the gang condenser towards BB104 Varactor diodes, but it didn´t work out. Over the decades, here in Europe the FM band is quite conjested requiring tighter channel separation than the old stereo 150Khz bandwidth. In some ways I got around this by using a rotatable 12 array Yagi directional antenna with good rear rejection. Still. with ajacent stations everywhere from several countries, the lock-in of the Auto Freq Control (AFC) and a good filter rejecting the pilot 19Khz/38Khz sidebands is necessary. Getting better than 1uV sensitivity for full limiting with tubes, is quite a challenge.

Fortunately, the move towards digital broadcasting has currently has stalled, maybe shelved, which would have rendered much of this old stuff obsolete.


Keep at it !
BB
 
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Nop I got the 1980's stuff (SAA1057 and TCA4500A BA809 IF coils and the tubes) on ebay - all worked fine. Just a matter of looking at the photo's and check that they look NOS - just like valves. Good thing with ebay - if its bust send it back.

I've put a link to the project so just posting in one place as diyaudio is more with amps.
https://funwithtubes.groups.io/g/main/message/70828

Great thing to try a FM or AM or SW receiver. Start with a bit of copper clad board and experiment.
 
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