On 6/2/2022 1:14 PM, Steve London wrote:
There is a 40 meter beam about 30
feet above it, but the 15 meter SWR does not change when either the XA or
40 is rotated, so I don't think there is significant interaction.
Hi Steve,
I've used NEC to study the possibilities of interactions like this on
other bands. The method is pretty simple. Build a model of a simpler
antenna like a 2-3 element 15M Yagi, and add a 40M dipole spaced like
your antenna is. Build that dipole with a load at the center that you
can set to either a short or an open. Driving the Yagi, set the visual
display of the model to display currents, and look for current in the
dipole. Do this for various positions of the dipole with respect to the
forward direction of the Yagi.
If you find current, I'll try to figure out what you might be able to do
in the 40M feedline to kill it.
73, Jim K9YC
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