Receiver for the 40m band LM602 (CB25305E)

This circuit uses an FM IF transformer for tuning. The circuit is from a Radio Electronics magazine from April 1990.

Absolute Value Amplifier (CB8997E)
This circuit, published in the 1980s, can be applied to operational amplifiers of almost any type....
Double generator (CB8943E)
Found in a 1969 Electronics World, this circuit generates low frequency signals with two...
Product Detector for SSB (CB4192E)
This circuit was found in a 1980s documentation for amateur radio. The circuit is for 9 MHz...