Using a 4046 PLL we found this circuit in the December 1989 issue of Radio Electronics magazine. The circuit operates at 220kHz, but this frequency can be changed by changing C3.
This low frequency doubler requires a 50 mV signal at the input. The circuit is from an old...
AEM's FM12 (QPL) series components are included in the latest edition of the European Space...
This simple circuit has its trigger point set in the trimpot. The transistor can be any general...