Cecil Moore wrote:
Jim Kelley wrote:
I agree that electromagnetic traveling waves are the kinds of waves
that propagate on and cause radiation to emanate from an antenna. But
your claims about 'standing waves not changing phase along the antenna'
...

Jim, I thought you have EZNEC.
Here are the currents at all of
the segments along a 20m dipole with 21 segments from end to end.
Please note that in a dipole that is 180 degrees long, the phase
of the (mostly standing-wave) current varies by less than 3 degrees.
How can the current in a 180 degree antenna vary by less than 3 degrees?

It seems to me that computers are completely stupid about certain
things. Could it be a case of garbage in, garbage out?

Quoting my web page: "Standing wave current cannot be used to directly
measure either a valid amplitude change or a valid phase shift through
a loading coil. All of the reported conclusions based on loading coil
measurements using standing-wave current on standing-wave antennas are
conceptually flawed."

And what more authoritative reference could someone cite than their own
web page? :-)

I've never actually known what it was that made you believe Roy had
measured standing wave current - whatever that means. Or, how his
measurements compare with your own measurements of the phenomenon.

Owen had an epiphany of a sort when he realized
that fact of physics.

It may not even be as elusive a fact as one is given to believe around here.

73, ac6xg



20m dipole 3/18/2009 5:28:50 PM

--------------- CURRENT DATA ---------------

Frequency = 14.2 MHz

Wire No. 1:
Segment Conn Magnitude (A.) Phase (Deg.)
1 Open .0836 -2.75
2 .23595 -2.57
3 .37707 -2.38
4 .50791 -2.17
5 .62692 -1.95
6 .73226 -1.71
7 .82218 -1.44
8 .89511 -1.13
9 .94979 -0.78
10 .98539 -0.37
11 1 0.00
12 .98539 -0.37
13 .94979 -0.78
14 .89511 -1.13
15 .82218 -1.44
16 .73226 -1.71
17 .62691 -1.95
18 .50791 -2.17
19 .37707 -2.38
20 .23595 -2.57
21 Open .0836 -2.75