This circuit was found in the September 1992 issue of Radio Electronics magazine. The circuit does not use a transistor to drive the relay and has no adjustments.
The circuit shown is from a 1993 documentation. It uses two FETs in an oscillating configuration that...
This output step with a transistor can be used in experimental radios and intercoms or as a signal...
This circuit, for bands above 15 MHz, was found in an Argentine publication from the 1970s. The L1...