This amplifier, whose mounting on a printed circuit board was described in Radio Electronics of October 1960, has 35 W of power. The power supply uses a transformer and a set of 5 tubes.
Using an LDR as a sensor, this circuit is from the Radio Electronics magazine of December 1984. The...
A frequency range determined by the network of resistors and capacitors with negative feedback and input...
The energy that powers this radio's amplifier circuit is obtained from the signal itself. The coil...