This circuit with an unusual configuration was found in the January 1974 issue of Radio Electronics magazine. The frequency is given by L1/C1, and the transistors admit equivalents.
This circuit was obtained from the November 1989 issue of Radio Electronics magazine. The circuit is...
This simple digital frequency meter using CMOS circuits reaches 5 MHz frequency. Input signals are...
We found this circuit in the 1960 Mullard transistor manual. The transistor is made of germanium....