Variable Phase Inverter (CB8143E)

Found in a 1966 American publication, this circuit invert the phase of a low frequency signal. The circuit has an intensity adjustment.

| Clique na imagem para ampliar |

Optical control notch filter (CB6717E)
This 1967 Raytheon circuit uses an optical coupler of the era and has a range of 800 to 200 Hz....
Even and odd counter (CB23780E)
This interesting digital counter with relays with complementary outputs was found in the Radio...
Dosimeter (CB5922E)
This circuit uses a diode as a radiation sensor. The operational ones are old because the...