When designing my own FM tuner I calculated that the thermal noise from the usual 100k resistor feeding the varicap might just about be relevant, so for the local oscillator I used a smaller resistor and a choke instead. I noted that few designs did this.
Most FM tuners have too much IF gain, which is why they have poor noise performance on middling-strength signals as the AGC works too soon.
Most FM tuners have too much IF gain, which is why they have poor noise performance on middling-strength signals as the AGC works too soon.
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