Found in a 1964 Electronic Design, this circuit uses a common LDR and transistors from that time. The relay is a high sensitivity type.
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...