On Mon, May 31, 2010 at 05:00:32AM -0700, sasas asasas wrote:
> thank you all of you for your answers.
>
> So more radials, means lower swr?
>
> Do you think that the variable capacitor is all i need for low swr? If
> i will not achieve swr<1.5 what do you think about to try to use a
> variable coil, which will be connected between the common point (of
> capacitor and 50ohm coax from transmitter) and ground. It will help to
> achieve low swr?
Typically, putting in radials raises the SWR, but you add them in
anyway because they make the antenna more efficient, allowing you
to radiate more signal instead of heating the ground with it. You
then add capacitors and coils to translate the antenna's native
impedence into something that will keep the coax feedline and
exciter happy. (And, to some extent, capacitors are preferred,
as they are less lossy than coils.)
Remember: A dummy load has a near perfect SWR, but doesn't radiate
worth a darn.
Rob
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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