This transmitter for the 3.5 and 7 MHz ham radio was found in a 1950s Japan publication. No information was given on the coils and the power supply.
The frequency of this circuit, that makes use of a tunnel diode as an active element, depends on...
This circuit uses a sensitive reed relay to control external loads. The time delay is given by the...
This circuit uses the 741 Operational Amplifier to drive two LEDs. The LEDs indicate the signal of...