We found this circuit in the December 1998 issue of Electronics Now magazine. RF transistors such as the BF494 or BF495 can be used. The circuit works at lower frequencies.
The integrated circuit used is a voltage reference from Motorola. This configuration was obtained in...
This circuit is from a Radio Electronics from October 1970. The circuit uses transistors from that...
This circuit was obtained from a 1977 magazine, but can still be mounted using BC548 for TR1 and...