Preamplifier stage (CB8934E)

This circuit is from a 90s Popular Electronics. It appears elsewhere on this site. Q1 can be any general purpose transistor.

Superheteredyne MW Receiver (CB962E)
This circuit, found in a 1958 magazine, is for reference only, since the components are not easy...
Darkness Monitor (CB21019E)
Found in Popular Electronics this circuit triggers an SCR and lights an LED when the location of...
International oscillator (CB9646E)
This OF-1 LO oscillator was found in a 1980s American documentation. The transistor can be any...