This circuit is from a 1976 amateur radio manual. The transistor can be the BD136 and the frequency adjustment is done in a potentiometer. The supply can be done with voltages from 6 to 15 V.
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
This circuit was found in documentation from the 90s, using components from that time. The...
This circuit, obtained from old documentation, allows the recovery of sulfated batteries. The...