Today this frequency corresponds to the end of the FM band. However, in December 1958, when the circuit was published in Radio Electronics magazine it was the frequency used by American satellites.
For times in the range of seconds to a few minutes we found this timer with the CK722 in a Radio...
We can use this amplifier with low impedance headphones with good performance. Possible...
Found in a 1964 Electronic Design, this circuit uses transistors from that time. Equivalent...