We found this circuit in an old American documentation, but the circuit can still be assembled with ease as the used components are still available. MOSFETs admit equivalents.
This simple field strength meter was found in a 1967 documentation. The transistor is germanium, and the...
This is yet another version of the light-controlled oscillator that can be found on this website. This...
Found in a 1969 documentation, this circuit for the 20 MHz band does not use a transformer. The circuit is...