This circuit also appears elsewhere on this site, obtained from other sources. This is an 80's American schematic book. Instead the lamp can be used white high-brightness LEDs.
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...