Roy, W7EL wrote:
"The response of electrically large (on the order of a half wavelength
and larger) dipoles and loops to electric and magnetic fields depends on
the direction and distance to the source."

Yes. The dierectional response of a 1/2-wave folded dipole is the same
as that of a 1/2-wave open-circuit dipole. The main difference may be
the difference in impedance presented to the transmission line.

Here is my experience. Lightning is an extremely large noise. My
corporation used VHF radios to interrogate remote data stations. For
decades we used Andrew Corporation folded 1/4-wave unipoles atop high
towers around the world in base stations to communicate with mobiles in
any direction. These had proved indestructable. Both the stainless steel
antenna and the radio used, with no lightning protection on the
feedline, other than the Heliax used to connect the antenna with the
radio. This was before we started the data radio operation. The Heliax
is a common-mode rejecter due to its equivalent circuit.

For the data radios, the operation was point-to-point. Directional
antennas were useful in this service. The data radios immediately
started to be destroyed by lightning strikes. Problem was the yagi
antenna. The driven element was an open circuit. We quickly fixed that
with an short-circuit 1/4-wave stub shunted across the antenna at its
feedpoint. No more lightning damage. The short-circuit removed enough of
the off-frequency noise (lightning) to save the radios. So the operation
continues decades later with Motorola transistorized mobile radios as
the data base and remote stations.

Best regards, Richard Harrison, KB5WZI