This circuit was found in 1980's Radio Electronics. The circuit produces a 1500 Hz modulate 35 kHz. The components used are still common.
April 2017 - Mouser Electronics already has the MAX4007 from Maxim Integrated in its inventory, an...
This circuit was obtained from an English magazine from 1979, but can be easily assembled today...
Found in a 1978 publication, this circuit uses germanium transistors and drives a small 20 to 50...