Terry, r2000swl, gave me this link to help me understand
antennas. It is an online version of a printed US Navy
electronic tech traning manual.

It covers many interesting topics.

I have a Log Periodic Dipole Array for my VHF/UHF scanner.
I didn't know that vertical versions for HF existed.

There are sections on the inosphere and propagation. All in all
a very good refference. I have ordered the CD version to have
it on hand.

Will