Found in Mallory documentation from 1968 this circuit uses an integrated circuit from that time. The circuit has a flat response from 10 Hz to 700 kHz.
This 80's National Semiconductor circuit uses an era integrated circuit and symmetrical 5V power...
This CMOS circuit is re-triggerable. It was found in the April 1988 issue of Radio Electronics...
The frequency of this circuit depends on the crystal. The transistor supports a modern equivalent. We...