Using a varactor or varicap, this 1969 Electronics World circuit has a modulation range from 75 kHz to 52 MHz. Modern equivalent components can be used.
Found in 1969 RCA documentation, this dimmer uses a dual time constant setting to achieve better...
Found in a 1968 Mullard manual, this circuit can function as an infrared audio link. The...
This circuit trips when the input voltage exceeds 30 V. Its base is a DIAC and it can be used to...