[Elecraft] Diversity at 50 MHz

[John Huggins]

Mike Scott wrote:
> I am building a 3-element 6-meter quad while waiting for my 2nd batch K3.
> Before final build a new thought...
> 
> Instead of building a quad I could alternatively make the spreader arms a
> little longer and configure two cross-polarized 3-element yagis. The thought
> would be to drive two receivers in polarization diversity.
> 
> Does anyone have any experince with the value of polarization diversity at
> 50 MHz? I am inexperienced on this band. I know everyone goes horizontal
> polarization for VHF weak signal work but once the signal gets refracted
> back to ground level the actual polarization may be rotated.
> 
> BTW, Lyle have you thought about ways to optimumly combine diversity
> receiver outputs other than just piping them into seperate ears? I could
> imagine actually calculating a time averaged received polarization angle and
> differential delay between channels and then combining...

For what it's worth many folks take the 3dB hit and combine the
horizontal and vertical feeds with a quadrature combiner (or you can
phase lag the horizontal and vertical antennas by 90 phase degrees).
This goes a long way towards reducing signal fade via polarization
rotation.  This is, of course, combining in the RF domain which I don't
think is what you were seeking.

The other folks in this thread suggest the polarization issues are not
too big a deal in the 6M band.  Perhaps.  One thing is for sure... your
high water mark in complexity need not exceed your dual Yagi with both
feeds ending up in your station where you can then select or combine
with arm chair comfort.  That kind of flexibility would be cool.

> 
> 
> Mike Scott-AE6WA
> Tarzana, CA (DM04/near LA)
> QRP-ARCI #12326/ KX1 #1311/ Swan 350C
> 
> 
> 
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