Transistorized Voltmeter (CB21919E)

Found in an old Raytheon transistor manual, this 4-scale voltmeter has an accuracy that depends on the input resistor network.

Transformerless Blocking Oscillator (CB19414E)
This circuit was found in a European documentation. Transistors are not indicated, but they can be...
Light-Controlled Oscillator (I) (CIR114)
This circuit uses a phototransistor as sensor. The changes in the resistance of the transistor,...
FM transmitter (CB15079E)
This small telephone transmitter uses a telephone capsule as a microphone. The L1 coil has 4 to 5...