Receiver for the 40m band LM602 (CB25305E)

This circuit uses an FM IF transformer for tuning. The circuit is from a Radio Electronics magazine from April 1990.

Triac driver (CB22446E)
The presented circuit uses an optocoupler to trigger a triac. We found it in a Popular Electronics from...
Triac Night Switch (CB12246E)
This circuit turns on incandescent lamps (do not use any other type) when it gets dark. The...
Divide-by-7 TTL (CB225E)
This circuit shows how to use the TTL IC 7790 to divide a square TTL signal by 7. Duty cycle is...