I acquired one at an estate sale. After testing it, I sold it. They do
work - however it seemed to depend upon the feedline for most of the
radiation. it does resonate - it is a top and bottom loaded coil. If you
can throw up an invisible 20 or 30 foot piece of wire, I think you would be
better off. It will work if you have no other options - but number of toher
antennas will work also. A motorized mobile antenna would work all bands
and be pretty hidden.

Colin K7FM