Shoot back in the 60s they could listen in on cradled phones in a room due to the micro voltages created by the transducer.
Shoot back in the 60s they could listen in on cradled phones in a room due to the micro voltages created by the transducer
And a few years later, the line powered transmitter.
Trim the antenna for your desired frequency on the am band.
They used to be ~ $2.00 each.
Simply installed in the network interface box outside the house.