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The TEA5711 radio IC and the Sony one were designed a long time ago and their radios are cheap.
Good modern radios like my car radio use a crystal controlled frequency synthesizer and don't nedd AFC to "fix the wandering frequency" of a station.
My cheap clock radios costed $1.25 and my Sony Walkman radio costed $19.00 about 15 years ago and they have the TEA5711 or the Sony radio IC with AFC.
My car radio doesn't have AFC. It snaps from one station to the next very accurately.I don't see any relation between 'cheap' and 'AFC'?
My car radio doesn't have AFC. It snaps from one station to the next very accurately.
Stations here are exactly 200kHz apart and my car radio changes its frequency in 200kHz steps.
My home stereo also doesn't have AFC. It doesn't need AFC because the stations in my area have their frequencies crystal controlled "and don't wander all over the place" like a cheap radio station or a cheap radio.
My 44 years old FM stereo receiver has an analog tuner and also doesn't have AFC. It has a tuning meter to fine tune the center of a station's frequency. Then nothing changes the frequency.
Imagine the mains frequency in a 3rd world country changing all over the place so much that a simple clock won't work accurately. Are their FM station frequencies the same??
The datasheet for the TEA5711 radio IC shows a 47k pot as a rheostat in series with a 68k resistor at pin 27 as the 19kHz/38kHz stereo VCO adjustment. They say to adjust it when receiving a stereo signal. Look at the stereo indicator and rotate the pot both directions to see where the light turns off and set the pot in between.Previously I have two stereo boards of the same IC. One thing I noticed is that there was a pot(10k or 100k) near to the IC on both of them. It was set on the middle by default. But I couldn't see any changes when I tried to turn the pot.
Guess what? My 44 years old FM receiver model 341 was made by HH Scott and it does not have AFC. It was one of their first ones that used an IC in the IF. It still works perfectly.
For those with short memory, I made (2) FM stereo receivers with the TEA5711/TDA7050 ICs, and the TEA5711 performs quite nice for such a simple circuit. The receivers can be seen here:
http://www.midcenturyradios.com/HM-FM-Stereo.html
http://www.midcenturyradios.com/HM-FM-Stereo-2.html