Medium impedance stage (CB20563E)

We found this circuit in an English publication from 1963. The circuit uses germanium transistors of the time.

144 MHz Super Regenerative Receiver (CB19600E)
We found this receiver for the 144 MHz band in a European publication from the 1970s. The circuit...
Receiver for remote control via powergrid (CB9577E)
The transmitter can be that of CB9574E. This receiver uses a PLL to directly trigger a sensitive relay....
Cardiac Monitor 2 (CB10962E)
This circuit was found in a 1987 magazine. It measures monitors the heartbeat through electrodes. The...