Cecil -

I was starting to think that this antenna is acting like a Carolina
Windom - and I was going to ask how to determine if there are common
mode current on the coax (thanks for the tip on the MFJ) . Is the 22'
length of the coax of the Windom critical or is that just a minimum
length? Also, if the coax is burried right below the balun at ground
level, does this at all act like a choke? Since I have a barrel
connector there I could also ground it at the point - any point to
that (besides lightning protection)? I guess if the choke
is working then grounding at that point will have no effect.

-Scott


Cecil Moore wrote:
wrote:
If the current is unbalanced, this would mean current is likely to flow
on the coax then? So perhaps the reason a voltage balun is used is to
merely transform the impedance 6:1 and purposely allow the feedline to
radiate? The maker of the antenna (Buckmaster) doesn't indicate any
particular length of 50 ohm coax be used, but I saw a huge change in
SWR and bandwidth on the upper bands when I lowered the antenna by 5
feet. Maybe this explains the behavior I saw.

The Carolina Windom is designed to radiate from the vertical
section of the feedline. You could duplicate that function
by installing a husky choke a few feet above ground. The MFJ-
853 is an inexpensive current meter that allows one to
measure the current on the coax braid. Mine arrived today.
It needs a little modification to allow the core to open
without needing the strength of Sampson.
--
73, Cecil http://www.qsl.net/w5dxp