This is the receiver from the previous alarm system. The circuit is from Radio Electronics, April 1989, and has an LDR as the sensor. Optical devices should be used to improve performance.
We found this circuit in Harris' 90s documentation. The circuit applies to modern operational...
Found in a 90s magazine for radio amateurs, this circuit can generate frequencies up to 45 MHz...
This is yet another balanced modulator circuit for SSB transmission. This two-diode circuit was...