What options do I have in bringing a longwire antenna and tuned
counterpoise ground to my tuner -- in addition to using the terminals
provided?

Unfortunately, the tuner is 15 ft from the window that both leads will
be coming in from. Rather then string the wires (both RF hot) across
the room, can I connect them to a balun and run co-ax? What balun?
Will I experience large losses in the coax?

Any point in hooking the two leads to ladderline and running that? If
that works, do I still use the ground and longwire terminals of my
tuner? Or the balanced antenna terminals?

If the ladderline works, how long can I make it? It would be more
convenient to have the longwire run to the trees from my attic (and
the counterpoise leave from there), rather than my shack. Could I go
to 50 ft of ladderline?

Ken KC2JDY



Ken
(to reply via email
remove "zz" from address)

On Tue, 21 Sep 2004 13:40:31 GMT, Ken wrote:

What options do I have in bringing a longwire antenna and tuned
counterpoise ground to my tuner -- in addition to using the terminals
provided?

Let me restate the question. The antenna is more properly a random
wire. The counterpoise is a multiband counterpoise made of rotor cable
with a separate [folded] resonant path on every ham band of interest
(here, 80 and 60/160)

Most sources say a random wire antenna is a dipole with one leg being
ground. Iam trying to apply this principle.

If my ground is instead a resonant [half wavelength] multi-band
counterpoise, Why can't this be treated like a balanced antenna? I
would like the random wire to leave my attic for a 225 ft [horizontal]
run through the trees and for the counterpoise to hang down along the
side of the house, leaving from the same spot in the attic. It seems
to me that connecting these two leads to ladderline should be the same
RF-wise as if I had a standard dipole there -- albeit with 50% less
efficiency.

The ladderline would run 50 ft to a tuner. I am not sure whether to
use the balanced antenna terminals (thereby involving a built-in 4:1
balun), or the random wire terminal and ground.

If I am missing something, I can't figure out what it is.

If I am onto something, Does the counterpoise have to resonant? Can
it, too, be a long [folded] wire? I understand that in some vehicular
apps, the counterpoise is made this way.

I am interested in knowing how RF hot the ladderline will be. It
would be best if it worked the same way it works with a standard
double zepp -- with each leg's RF cancelling out the other.

Ken KC2JDY

Ken
(to reply via email
remove "zz" from address)

On Wed, 22 Sep 2004 09:01:01 GMT, Ken wrote:

balanced antenna 225 ft [horizontal] +counterpoise to hang down along the
side of the house

Hi Ken,

Your question also contains the answer as noted above. This is a
formal definition in response which in an of itself does not negate a
practical outcome.

leaving from the same spot in the attic. It seems
to me that connecting these two leads to ladderline should be the same
RF-wise as if I had a standard dipole there

Reasonable assumption, but there is nothing balanced about it that
confers the characteristics/benefits of being balanced. Balance is
with regard to two sides of a dipole, each in relation to ground. If
one of those two is intimately associated to ground (you qualify in
spades here), then the system is unbalanced throughout.

This gives rise to unbalanced currents AKA common mode. However,
common mode may pass unnoticed, and in such case it simply doesn't
matter. This balance is easily qualifiable visually: does each leg
offer symmetry to the other AND ground? Yours does not. There is
nothing fundamentally balanced about a long wire in the first place
irrespective of counterpoise treatments. This does not diminish any
perceived benefits of that counterpoise, but the counterpoise does not
confer balance as you describe it.

As to the matter of ladder line and its practicability. At this point
its choice is driven by the expectation where you anticipate large
mismatches and losses that attend them. Thus the ladder line answers
the problem of loss, otherwise it has no particular merit over other
methods. To respond directly to your statement above, yes you can
attach ladder line RF-wise as if you had a standard dipole.

73's
Richard Clark, KB7QHC