Amazon.com: MLA-30+ Loop Antenna, 100kHz-30MHz Active Receiving Antenna, Rainproof Loop Antenna for HA SDR Short Medium Wave Radio, with 10m Feeder,Built-in Low Noise Amplifier,for Rooftop,Balcony : Electronics
Magnetic Loop Antenna - Schematic off the "military" coupling concept used here with printed circuit board and rotor capacitors... Works the same as other loops described here. Q is around 140 and
Feeding the Loop | Details | Hackaday.io
Portable magnetic loop antenna | VK3IL Blog
Comrod Communication Group - Army Technology
Nos WwII Military Aircraft Radio Bendix Army Navy MN-20E Rotatable Loop Antenna | eBay