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.

Delay Circuit (CB10930E)
This circuit was obtained in a 1991 Electronics Handbook. The publication no longer exists, but...
Timed Relay (CB21866E)
We found this circuit in Ferranti's 1974 transistor manual. The components are from the period. Note...
Instrumentation Amplifier (CB12173E)
This instrumentation amplifier was obtained from Popular Electronics in 1993. The operational...