This circuit generates signals whose frequency depends on C1 and C2. JFETs are common types like BF245 or MPF102.
This 6 transistor TR26 commercial radio was sold in Japan in the 60s. It is a super heterodyne circuit...
This circuit indicates the resistance of the skin of those who hold the electrodes. RV1 makes the...
This transmitter, found in Raytheon documentation from 1957, has a range of a few meters. L1 can...