Preamplifier stage (CB8934E)

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

2-Transistor Amplifier (CB22508S)
This 1950's circuit used one of the first commercial transistors and had two stages for audio...
Audio compressor (CB22154E)
Using integrated circuits from the time, we found this audio compressor in an English publication from...
Micro Radio (CB18167E)
This is an experimental crystal radio that uses no power source. The antenna must be very long (at...