This simple circuit for the 3 to 30 MHz range was found in the Electronics Experimenter Handbook Special Projects of 1983. The coils consist of 10 and 50 turns of 32 wire on a 1 M x ½ W resistor.
When the control level is increased from 0 to 1 (LO to HI), this circuit is activated, which...
This 1950's circuit used one of the first commercial transistors and had two stages for audio...
This amplifier can be powered with voltages from 9 to 14 V providing 7W of maximum power under a 8 ohms...