This is a classic FM amplifier IF amplification stage configuration. The circuit is from a 1980s documentation. CN is the neutralizing capacitor.
Found in documentation from the 1980s, this circuit makes use of discrete components of the time....
To operate in a harmonic of the crystal frequency, tuned to a trimmer in the resonant circuit of...
The possibility of using the 4013 in the monostable configuration added to the input sensitivity of the...