Found in documentation from 1924, this receiver has several sets of coils. Power is supplied by several batteries and listening on high-impedance headphones.
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...