In message , Cecil
Moore writes
Merlin-7 KI4ILB wrote:
Now all I need to figure out is how to keep the 10 meter and 11 meter
antennas from interacting too bad or place them in such a way that the
interaction does something that is usefull...

Here's an idea. Use the 11 meter antenna for 10 meter
operation by switching in a series capacitor. All you
need to do is to neutralize the small amount of inductive
reactance on 10m caused by the antenna being a tad too
long. The capacitor could be switched in and out by a relay.
I get a value of ~330 pf to perform that function. The
SWR on 10m will actually be better than it is on 11m.

Or you could use the capacitor with the second 102 inch
vertical without having to cut it.

I did exactly this (20 years ago). I used a variable compression trimmer
capacitor to check that I could actually get a low SWR, measured it, and
fitted the nearest value disc ceramic (rated at 500VDC). I think it was
330pF. No problems with 40W.
Ian.
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