this looks like it would be a nice portable option. You can build your own loop and loop-like antennas, of course. Some of them can be quite portable.

In this video, learn how to create the world’s strongest antenna right from home. With a few simple materials and expert techniques, you can build a powerful antenna that outperforms commercial ...

“Fast Multi-Polarized Magnetic Field Measurements in the Frequency Range Between 150 kHz - 30 MHz,” investigates key aspects of existing low-frequency magnetic field measurements below 30 MHz and ...

The 360° rotating AM antenna pulls in even the weakest of signals ... COMPACT TRAVELER RADIO - Tune in to your favorite AM, FM, longwave or shortwave bands with manual & digital tuning!

Or in the case of [MM0OPX] trying to find fly fishing reels that are suitable for his Adjustiwave multi-band VHF-HF ham radio antenna ... out the walk around and build discussion videos ...