Review on Kaito AN-100: Tunable Loop Antenna for AM Radios- Compatible with Kaito, Sony, Panasonic, Grundig, and More by Gilbert Cokky

This is an excellent loop antenna for collecting AM radio signals. It's passive, so it doesn't require power. The tuning knob maximizes reception on the frequency you are trying to track. I use this with Sangean WR-22. I suffer from electrical interference like many modern homes. The loop antenna works with the magnetic portion of the RF signal and can be rotated to "cancel" electrical noise. Most radios, including my WR-22, have an internal ferrite rod antenna and work well if you rotate the entire radio to minimize noise. Some radios, like the WR-22, have jacks for an external AM antenna, but they don't have a switch to disable the internal antenna, so noise is simply added to the combined signal. I opened up my walkie talkie and unplugged the ferrite antenna and now the walkie talkie only works with an external antenna. It's quiet and the reception is very good!