We found this circuit in a 1964 Electronic Design. It provides 0.5 V signals from 4 kHz subcarriers. Transistors are from the era.
This receiver receives signals from the VHF band with earpiece or application in a power stage. The...
Originally created to power an 80's RTTY printer, this circuit can be used in other applications. The...
This circuit is from a Popular Electronics of the 90's. Any power MOSFET can be used. The circuit...