[Elecraft] Long wire antennas MORE

[David Gilbert]

There is only a fixed amount of total energy contained in all the lobes 
of an antenna.  You almost definitely did get lots of lobes ... but you 
also got lots of nulls that exactly offset all those lobes.  You just 
never heard the the hams that were in those nulls and they never heard 
you.   Whatever you gain in one or more directions is sacrificed in one 
one or more other directions.  This is basic physics.

More lobes is not necessarily better.  In fact, taken to the extreme it 
is self defeating because a very large number of lobes (assuming they 
were somehow all of equal strength as you stated) begins to approximate 
a unidirectional antenna with no azimuth gain in any direction.

Just for grins I modeled your 700 foot antenna in EZNEC+ and on 20m it 
gave a maximum gain of about 9 dbi in a fairly narrow lobe at 16 degree 
elevation in both directions along the axis of the wire.  It also gave a 
total of 36 other sharply narrow lobes arrayed symmetrically in all 
other directions, each with a gain of about 6 dbi.  Between each lobe 
was a deep null of around minus 10 dbi. This was all at the same 16 
degree elevation angle ... there were literally too many lobes to count 
on the 3D pattern, with lots of lobes and nulls at every azimuth and 
elevation angle.

A simple dipole at the same 40 foot height would have given similar gain 
with a much broader lobe (both azimuth and elevation) in the two main 
directions, but of course without the multiple smaller side lobes.  
Three poles and two perpendicular dipoles would have given better 
overall single band results ... the only advantage of the long wire 
being that it gives a similar pattern along with similarly ugly match on 
multiple bands.

Dave   AB7E


On 1/11/2018 9:41 PM, William Levy wrote:
> Let me tell you what I observed with 700 feet of long wire.
>
> QSB disappeared. What faded on one end was rocketing in on the other end.
>
> I pointed the antenna at the USA from Kenya. There was nobody in the USA
> that could not hear me. I ran 100 watts.
>
> I had lobes going in every direction. I had huge gain forward. Check the
> ARRL antenna book. It worked off the end and the front and the side.
>
> It was the best wire antenna I ever used.
>
> Best of all the elephants walked around my old Army Signal Corp 40 foot
> poles bought new from Fair Radio Sales. That's right. The Elephants walked
> around the poles. The sag in the middle was pretty deep but still taller
> than an Elephant.
>
> The longer the wire the more forward the gain. The better the lobes.
> I never used a better wire and if I had to do it again I would do it again.
>
> 73 all, Bill
>
> The science is simple. The more wire hanging out the more signal radiating.
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