This circuit is from a Radio Electronics from March 1970. The crystal depends on the frequency at which the signal is to be captured and the resonant circuit determines the tuned band.
Found in Popular Electronics from the 90s, this circuit uses a 2N2646 and a general-purpose transistor...
The crystal frequency of this circuit found in an American documentation is limited only by the...
These two circuits were found in Radio Electronics magazine from February 1960. The transistor is a power...