The speed indication of this circuit is made on an analog instrument. The circuit is used to count pulses (rpm) and was found in April 1976 Radio Electronics magazine.
Using two 567 PLLs, this circuit recognizes two audio tones in sequence providing a signal for a...
We found this transmitter in a documentation on espionage from the 90s. The circuit is...
We find this circuit in a Radio Electronics of July 1984. It consists of the traditional version of 1 A...