Jim,
You got it. That is why my first recommendation is for ground
independent antennas. For portable use, any antenna that can be hung by
a single support should work nicely so long as it approximates 1/2 wave
on the lowest frequency. An inverted V with it's center up a tree fed in
the center with ladder line from a small current balun will work nicely,
and it could even be sloping if the center can't be high enough. I have
found sloping delta loops work nicely when fed with ladder line and a
4:1 balun. DO NOT worry about matching. If you are reading this, you
probably have Elecraft gear. That means you really need a truly awful
mismatch for your tuner not to be able to deal with it.
73,
Barry
K3NDM
------ Original Message ------
From: "Jim Brown" <[email protected]>
To: [email protected]
Sent: 8/13/2017 1:10:17 PM
Subject: Re: [Elecraft] Is it my KX3/antenna or is it lousy band condx?
On 8/13/2017 9:09 AM, Walter Underwood wrote:
The 16 foot wire on the ground is a radial “system”. One radial is a
lot better than none, but you could use more. The length isn’t
especially important
Right.
because it is capacitively coupled to the ground.
It's also inductively coupled. BUT -- that's NOT how or why radials
work. AND a connection or coupling to earth does NOT make a
transmitting antenna work better. That's because the earth is a big
resistor, so it burns any power fed into it, whether with a direct
connection or by capacitive or inductive coupling. In other words, it
WASTES transmitter power.
Ground resistance swamps any resonance.
Yes, but as noted above, not in a good way. :) There's a folded
dipole antenna made with a big resistor in the middle of it, the effect
of which is to "broadband" it by "swamping" the resonance, AND to burn
half of the transmitter power. In other words, the transmitter puts
power into the antenna, but half of it is wasted in that resistor.
73, Jim K9YC
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