Thanks for all the replies - many were direct to me. There was a range of
answers from: my 2m mast mount PA gets slammed, to I have the antennas
stacked 5' apart and there's no issue with legal limit. For filtering,
some used low power band pass filters before the amp, some used HP BPF's
after the amp, and one person used a stub.
It turns out one of my group has an ICE 6m 3KW BPF which I will use after
the 6m amp, and we have 2m BPF too. We figure that should do the trick.
While I was researching the issue, I ran into the following which may be of
use:
Bud Radio Inc variable low pass filter LF-601 or LF-601-A, which is rated
at 1KW AM and factory set to cutoff after 33 MHz. There are some on Ebay
right now. If you have a network analyzer, these should be easily retuned
to cut off after the 6m band, which will suppress the 6m 3rd harmonic into
2m
73, Kenny K2KW
On Wed, May 3, 2017 at 11:35 AM, Kenneth Silverman <kenny.k2kw@gmail.com>
wrote:
> Has anyone successfully used coax stubs on the output of the 6m amp to
> suppress 3rd harmonic interference into the 2m station (M/M station)? If
> so, did you use a single or double stub?
>
> The antennas will be on separate masts, spaced about 40' apart, and 6m
> will run about 700w. In most cases the antennas will side to side and
> roughly pointed in the same direction, but the beamwidth of the 6m antenna
> is wide enough where the 6m antenna could be pretty much looking into the
> (side) of the 2m antenna.
>
> Many thanks, Kenny K2KW
>
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