Topband: [TowerTalk] 160 vertical question (Top Hat)

[Herbert Schoenbohm]

Paul, By doing this you are actually tuning out the inductance caused by
the longer than resonant wire by adding a series capacitance near the same
value.

Herb, KV4FZ

On Sun, Feb 4, 2018 at 8:35 AM, Paul Christensen <w9ac at arrl.net> wrote:

> >"Another technique that is often used for matching is to make the wires
> much longer than resonant (that is, resonant around the top of the BC
> band), so that the feedpoint Z is 50 +jX ohms (that is, inductive) on 160M,
> and tune the capacitance out by adding a capacitor of equal value in
> series.    NEC can easily model this."
>
> When over-resonating with a long T-top, the maximum current point moves
> away from the ground and up toward the center of the vertical radiator --
> another benefit.   Unless there's a deliberate need to resonate on the
> operating frequency (e.g., with some phased arrays), then over-resonating a
> single T-top vertical radiator should be the objective, subject to the
> availability of long, tall supports on either side of the vertical section.
>
> Paul, W9AC
>
>
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