This is the traditional audio preamp configuration with the National Semiconductor LM382. The circuit has good gain and can be used with magnetic pickups or from signals from an auxiliary input.
This test, the commercial transistor tester, had its diagram published in an article in Radio...
Aiming to generate signals in the bands used for maritime communications, this signal generator was...
This circuit for the 11-meter band, operating at 29.255 MHz was found in a Radio Electronics dated...