Cecil Moore wrote:

Mark Keith wrote:
Yep, fed with coax, but being the mismatch wasn't that large in the real
world, the loss shouldn't have been overly bad.

Egads, that is the whole problem. The mismatch was terrible.

No, it wasn't terrible. Not by a long shot. But I'm sure height,
surroundings, etc, etc influenced this outcome. On paper, yes, it
*should* have been bad. This sure wasn't the problem in the next
example.

It's like when I was out camping using a ladder line fed 80m, 130 ft
dipole. I tried it on ten. It was pathetic due to the overly high takeoff
angles.

Absolutely false! The TOA of a 130 ft. dipole on 10m is about 10 degrees.
MOM+physics, not your feelings, dictate that fact.

My feelings had nothing to do with it. My friend, who was the one that
wanted to get on 10m in the first place, called people until he was blue
in the face. Not a single one answered him. It was like all our signal
was shooting off into space overhead. Which is what was happening for
some reason. It wasn't excess tuner loss, because I always use the bare
min inductance needed to tune. It wasn't the feedline. It was overly
high angles of radiation. Probably because the antenna was fairly low.
The TOA of a 130 ft dipole will depend on the height above ground. You
state gain numbers, yet you don't ask how high the dipole I used was.
It's the all important "missing link". The dipole we used was probably
15-20 ft off the ground. Model that on 10m at 20 ft and see how it
looks. Probably even worse at 15 ft. Looking at the elevation plot, the
angle of max gain is 24 degrees at 0 degrees azimuth angle, and 28
degrees at 90 degrees angle. I show negative gain "dbi" at all angles
below 10 degrees.

Compare this with a lowly 10m 1/4 wave GP at 8 ft off the ground. This
leaves the sloping radials at 2.5 ft off the ground. Max gain is at 13
degrees. You don't see negative gain until 4 degrees or less. It will
beat your gain-daddy dipole in most all directions on long low angle
paths or ground/space wave I suspect. I know my mobile antenna trounced
the one we used. MK


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