LZ1AQ's page for SDR Radio and Active Loop Antenna
SDR Transceiver and Receiver Antenna Sharer TR Switch Box with Gas Discharge Protection 160MHz
0.1M-180MHz Active Loop with Receiving Antenna Kit For SDR Radio K-180WLA | eBay
Amazon.com: RTL‑SDR R820T2 V3 RTL2832U Software Defined Radio Smart HF Bundle Antenna with RTL2832U ADC Chip for Computer Based Radio Scanner 480 kHz to 1.87 GHz : Electronics
RTL-Software Defined Radio with Dipole Antenna Kit | Elektor
Wideband Antennas for SDR Radios (#396) - YouTube
Software Defined Radio for Mariners: AIS Antenna Design Review