This is an amplifier circuit intended for modulating transmitters. The 5-tube circuit is from an American manual from 1947. The power supply uses a transformer.
This simple experimental circuit using only transistor produces a tone given by C1 and C2. Tone is...
This power supply may have 5, 6, 9 or 12 V outputs depending on the 78XX and 79XX series...
This circuit is from Philips' 60s documentation. The circuit can be applied to modern operational...