Are you trying to pull our leg? A google search for "Chelton Loop"
antenna turns up only references to a street, Chelton Loop, in Colorado
Springs. If there's a "Chelton Loop" antenna, it must not have had
much written about it.

If you want to detect magnetic fields at HF, a small coil of wire
should work well. The size would depend on the size of the magnetic
field you're probing, and the spatial accuracy you want. If you want
to receive electromagnetic signals, as others have posted, be careful
about claims of sensing "only" the H field.

Cheers,
Tom

wrote:
Is anyone aware of any sources of information/theory on H Field
antennas, such as the Chelton Loop for HF?