I suggest you put up the 15M and check how much the SWR on the 20M
antenna changes. I don't think it will change much at all. If the SWR
doesn't move then you don't have a problem.

Also, if you use a relay to disconnect the 15M antenna from it's coax
at the base of the antenna then you get a 42MHz resonant half wave
which will be even more out of the picture for your 20M antenna.

Bob AC7PN


Zommbee wrote:
Hello again,

How close to my 20-meter mono-band vertical could
I put a 15-meter version of the same? I have a great
spot that's only about 10 feet away - will there be
negative interactions of the two? (Of course, it would
be nice if the sun had a few more spots!)

Thanks

Dave WB7AWK