SV: LF: 137 Carrier

["Johan Bodin" <sm6lkm.jbeab@swipnet.se>]

Hello Rik and others.

A selective voltmeter can be built using a gyrator. If you
have "The LF Experimenters Source Book" (RSGB), take
a look at the gyrator tuned VLF receiver on page 3.7.
The gyrator is described in more detail on page 5.1.

With suitable OP-amps (fast!), I guess that such a circuit
can be useful as a QSB monitoring receiver on 137 kHz.

73 de Johan