This Vienna bridge multi-band oscillator circuit was found in a 1974 Ferranti transistor manual. The circuit generates signals from 25 Hz to 1 MHz in 5 bands selected by the capacitors.
This protection circuit for standing waves was found in a manual of high frequency circuits and...
We found this circuit in a Popular Electronics of the 80s. Used integrated circuits are uncommon...
This experimental circuit with Nixie tube was found in the Radio Electronics magazine of March...