[BC] Slant wire feeds vs series fed

[Phil Alexander]

On 25 Jan 2006 at 7:08, Richard Fry wrote:


> Does anyone know of a shunt-fed, monopole installation where the feed wire 
> is inserted at the tower base, makes a 90-deg bend, and extends up in the 
> vertical plane on the tower vertical C/L to attach at the feedpoint?

> That would eliminate feedline radiation in other than the vertical plane, 
> and remove the "skywave" and DA issues with slant -wire feeds.  

While that would be accomplished, it would work like an inside-out skirt,
only with less flexibility WRT wire location, hence (I'd think) Q. IOW,
the b/w could not be manipulated as it can by extending the support arms
as with a skirt.

> The tower might also shield the feed wire somewhat from lightning/EMP 
> problems.

Maybe I'm missing something, but I don't see that. The current through
the tower in the event of a strike is going to induce current in the 
feedline regardless of where the feed line is located. Since the entire
tower will "receive" or be sympathetic to lightning activity within a
few miles. The feedpoint "snapping" activity for a slant wire feed is 
at least as vigorous the base of a series fed tower during a nearby
thunderstorm.


Phil Alexander, CSRE, AMD
Broadcast Engineering Services and Technology 
(a Div. of Advanced Parts Corporation) 
Ph. (317) 335-2065   FAX (317) 335-9037





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