Found on a 1964 CQ this circuit is intended for tone frequency change modulation (FSK) telegraphic transmissions. It operates with signals of 2.975 and 2.125 Hz.
This low frequency circuit was found in documentation from the 1980s. The values of R and C...
The 4528 is a dual-retriggerable monostable that needs only the timing network formed by R and C...
This ttransistor test was found in a 1987 documentation. It is a simple oscillator that allows to...