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
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