Topband: Beverage feed line...too long?

[K9AY]

from IZ4EFN:

> The beverage is 200m long (600ft) and 6 feet (2m) above the ground. The 
> feeding line is a 300m (900ft) RG-58 MIL line.
> The K9AY is feeded with 200m (600ft) of the same cable.
>
> Actually, the two antennas show the same noise level, and almost same 
> signals in that direction.
>

Alessio,

Since you say the two antennas have the same noise level, I believe that 
both of them are experiencing common-mode problems on the long feedline.

There are many ways to help, which have been discussed on this reflector, 
and noted on W8JI's fine web site. The 'easy' first things are to be sure 
the transformer has separate primary and secondary windings, and that the 
antenna and feedline are grounded to separate ground rods. Next is to choke 
the feedline, as others have described.

73, Gary
K9AY