> In addition to the Mosley tri-bander I have acquired a 5 element 6M beam
> that I want to mount above the HF antenna. Does anyone know the minimum
> distance that should be maintained between these two antennas to reduce
> any interaction? Something stays in my mind about 1/4 wavelength
> separation. That would result in about 6 ft of vertical separation between
> the two antennas.
>
> Am I on the right track or do I need to put this 6M antenna on it's own
> mast/tower??
The general rule, although it sometimes varies with the particular antennas
used, is the higher frequency antenna determines the minimum spacing. This
is because in almost all cases the higher frequency antenna is transparent
to the lower frequency antenna. The lower frequency antenna is almost never
transparent to the higher frequency antenna.
A good rule is to keep the higher frequency antenna 1/2 wave at the higher
frequency band above the lower frequency antenna. That would be three meters
for a six meter antenna.
Many times in a case like yours it can go much closer, especially if the
higher frequency antenna has a similar or longer boom than the lower
frequency antenna or you get lucky with avoiding six meter resonances in the
lower frequency antenna. The best practice is just model it, or if you
can't..... keep it as wide as possible but not over 10 feet.
73 Tom
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