On Tue, 08 Feb 2005 00:06:25 +0800, Dan Jacobson
wrote:

Can one in theory still transmit if rain
water creates a bridge across the driven
element, or even also to 'ground'?
A DC short circuit but not a RF short circuit?
Or is it just salt water that is worrisome?


I have a multi-band dipole, similar to the fan-dipole. A couple of
weeks ago the rain coated my antenna and bridged the gap between
center and shield on my coax. My antenna went from matching 80, 40
and 20 to matching 12 and 17. This was short lived, but it lasted
long enough for my friend and I to get a good laugh.

Typically, without the ice, the weather shifts the center of resonance
on my antennas. Sometimes it kills the use of a band or in case of 80
meters, it shifts from the SSB to CW (or visa versa).

I threw this antenna up in a hurry and added to it off and on over
time. It was supposed to be temporary so I didn't use a balun or
weatherproof the so-called cobra-head, which is really only a piece of
PVC with three holes drilled in it and the center to one wire and the
coax to the other.

I also have a properly built 20 meter antenna where I ran the coax
into a PVC t-connector and the wires connect at points several inches
away so there is no water bridge and the coax stays dry.


--
73 for now
Buck
N4PGW