3-tube receiver (T1602E)

Found in a 1949 Radio Electronics, this circuit employs vacuum tubes of the time. Power supply not provided.

Flat Response Low Pass Filter (CB9770E)
Found in American documentation from the 90s, this circuit can be applied to other operational ones. We...
Darlington Photo Trigger with Reset (CB14659E)
We found this circuit in the Texas Instruments opto-electronics manual. The button resets and the...
Field Strength Meter (CB13267E)
We found this circuit in an old American publication. The transistors can be BC558 and diode 1N34....