Topband: Silent Feedline for RX antennas

[K9AY]

> Actually using fully balanced line won't fix any problem, the
> problems will remain and likely increase significantly.
> 73, Tom W8JI
---------

Tom is right. Balanced line is not a "silver bullet" fix for feedline pickup.
And he is right that it can make matters worse -- any added complexity
introduces new opportunities for problems.

To reduce feedline pickup of noise and extraneous signals, the fundamental
techniques are:

* Reduce coupling between the feedline shield and the antenna due to proximity,
by common-mode coupling through the matching network or via ground currents. All
have been discussed at length on this reflector.
* Reduce coupling to other antennas, towers, power lines, etc. by careful
placement of the antennas and feedline routing, and by improved shielding (e.g.
buried feedline).
* As a last resort, you can increase S/N by placing the preamp at the antenna
end, before the feedline effects are added.

73, Gary
K9AY