[Elecraft] Long wire antennas

Don Wilhelm donwilh at embarqmail.com
Thu Jan 11 00:09:04 EST 2018


Frank and all,

While it is true that radiation off the end of a long wire is a deep 
null,  The maximum radiation will be at an angle to the wire greater 
than 1/2 wavelength (less than 90 degrees).  That angle will depend on 
the length relative to wavelength.

A look at the radiation pattern of long wires and other Traveling Wave 
antennas will reveal that fact.  The rhombic antenna and V-beams use 
that characteristic for their gain and directionality.

73,
Don W3FPR

On 1/10/2018 11:40 PM, donovanf at starpower.net wrote:
> Ron,
> 
> 
> What you've come to understand is absolutely false except for the
> special case of a long wire close to the ground. That special case
> is called a Beverage antenna that radiates vertically polarized
> radiation off the ends.
> 
> 
> When you raise a long wire antenna more than about 0.05 wavelengths
> above the ground, horizontal polarized radiation becomes dominant
> and the radiation pattern always has a deep null off the ends.
> 
> 
> 73
> Frank
> W3LPL
> 
> ----- Original Message -----
> 
> From: "Ron D'Eau Claire" <ron at cobi.biz>
> To: "Elecraft Reflector" <elecraft at mailman.qth.net>
> Sent: Thursday, January 11, 2018 4:08:40 AM
> Subject: Re: [Elecraft] Long wire antennas
> 
> Understand that a true "long wire" (greater than 1 wavelength) starts to be
> directional off of its end (if fed at one end, that's the opposite end).
> 
> 73, Ron AC7AC


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