This circuit triggers a buzzer or other warning device when the light falling on the sensor is cut off. We found it in the Encyclopedia of Electronic Circuits Volume 5 of 1995.
This analog TV circuit can be used on a small transmitter. The circuit is from an 80's American...
This antenna or booster amplifier operates with signals from the midband (MW) range up to the VHF...
This circuit was found in a documentation for radio amateurs from 1978. The resonant circuit...