Found in the May 1971 Radio Electronics magazine, this is the circuit for a commercial high-impedance instrument. The circuit uses 4 transistors and is powered by 2 9 V batteries.
The oscillator shown in the figure can generate signals between approximately 3 and 15 MHz,...
This circuit was obtained in a QST magazine from the 90s. The circuit makes use of components that are...
Suggested by General Electric in 1966 documentation, this circuit uses unusual components today....