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.
The modified Hartley oscillator, seen in figure 2, can generate signals ranging from 3 MHz to 10...
This circuit produces a high voltage (above 5,000 V) to ionize the air around a needle that acts...
Found in American documentation from the 90s, this circuit provides three timings given by the...