The purpose of this circuit is to measure the resistance of an antenna at the resonant frequency. The circuit is from an old American documentation for hams.
When this circuit picks up a louder sound it produces a pulse that briefly charges the 10 uF...
This circuit was found in a publication from the 50's. The circuit uses germanium transistors of...
I found this circuit in a 1974 magazine, but it can still be easily assembled because the...