This is the typical audio amplifier for a 1967 television. We found it in a magazine from the time. Note the use of the output transformer and the high supply voltage. The circuit is an RCA CTC21.
Placed near a telegraphic transmitter (CW) and with a small antenna or pickup, it reproduces the...
The LM387 integrated circuit used in this project is not very easy to obtain. The circuit, from an...
The recommended distance between the emitter and the sensor of this coupler is 15 mm. The circuit is...