On Sep 18, 4:58*pm, "Dave" wrote:
"joe" wrote in ...
Many antennas are built using tubing for light weight. So, if there is a
current flowing in the middle, it is good that the ends of the tubes are
crimped, or plugged. I wouldn't want the flowing electrons spilling out
onto my lawn.

thats why they put those plastic plugs on elements, to keep the magical
mystery dielectric particles from falling off instead of going back up the
middle... if you ever lose the plastic caps you will notice the antenna
starts leaking and the particles pileup in your yard making a real mess.

If the inside is covered with an eddy current field the particle
cannot get to the aluminum
which debunks the idea that the electron can penetrate evreything.
Forgeting the fact that it is searching for a
diamagnetic surface to rest upon. The same situyation is repeated
inside a wave guide.
Do you think I could put "Doc' with my name to impress people?
Art Unwin...KB9MZ