Found in a 1969 Ferranti documentation, this circuit uses only bipolar transistors from that time. Transistors can be replaced with modern equivalents.
Indicated for activation by microcontrollers, this circuit was found in the Radio Electronics...
We found this circuit in an English publication in 1991. The circuit can be assembled with...
This tuner circuit was found in an old English documentation. The JFET can be any general purpose...