1-Ttube reflex receiver (T1555E)

This one-tube circuit is equivalent to the previous one. We find it in a 1924 book by Gernsback, Power is made by batteries.

Differential relay (CB8839E)
Found in a 1969’s Electronic Design, this circuit operates in a narrow range of voltages....
Power stage (CB23766E)
This power stage with two counterphase transistors and coupling transformers was shown in Radio...
300 Hz Flasher (CB6800E)
Found in old documentation, this circuit uses special discharge lamps (neon) of the time. The...