[TowerTalk] Wire antenna?

[David Gilbert]

That is correct.  Phase flips every half wave as you travel away from 
the feedpoint.

At one point in the past I had a 160m Inverted-V that I fed in the 
center for approximately a dipole pattern (I say "approximately" because 
it was low enough to be more omnidirectional than not).  For 80m, I fed 
that same antenna at 25% from one end to get the cloverleaf pattern 
while still having a low feedpoint impedance. With the antenna aligned 
north/south, the 80m pattern from here in Arizona gave me NW 
(Washington/Oregon), NE (most of east coast), and SE (Caribbean) with 
California workable via the high angle "backside" because they were so 
close.

The cloverleaf pattern was actually more effective than a classic dipole 
figure 8, although of course I have no idea how much feedline radiation 
I was unable to choke off.  In any case I never noticed any problems 
during the fairly brief period I used it.

73,
Dave   AB7E



On 7/1/2019 9:27 PM, K9MA wrote:
>
> For an end fed wire, this is not true. Its pattern has 4 lobes, a 
> cloverleaf. It is like a full wave fed 1/4 wave from one end. That's 
> two half waves OUT of phase. A center fed full wave is indeed two half 
> waves in phase, and has the dipole-like pattern, a bit sharper, with a 
> bit of gain over a dipole, and a very high feedpoint impedance.
>
> Because of the cloverleaf pattern, an end fed full wave can be quite 
> useful. At higher harmonics, the lobes proliferate, and tend to get 
> concentrated towards the axis of the wire, which is often less effective.
>
> 73,
>
> Scott K9MA
>