This receiver, whose tuning range depends on L1 and L2, was found in the 1992 special edition of Radio Electronics Experimenter. The circuit is relatively simple and has good sensitivity.
This General Electric circuit is from the 80's. The PUTs used in this meter are not common...
This circuit provides a power of the order of 2 W, characterized by high performance. The output...
The sensor can be made using two bare wire or two screen with a piece of tisse between them. One...