In fact, this circuit from the 60's applies to photographic printers of the time, timing the lighting of a 20 W lamp. The components are from the period.
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...