This circuit can detect static charges or extremely low voltages. The circuit was found in ancient American documentation and makes use of a JFET. A BF245 which is a more modern transistor can be used.
We found this circuit in a 1973 documentation. The null adjustment trimpot is 10k. The circuit can be...
This commercial transistor radio was manufactured in Japan in the 1960s. The circuit has only 3...
This FM transmitter was described in the Radio Electronics magazine of June 1963. It operates in...