[amsat-bb] Re: Comparison Quadrifiar verses TMP ll

[i8cvs]

Hi Norman, VE3CJE

I don't know how the Texas Potato Mashers II works and if it can be
switched between RHCP to LHCP or not but the Quadrifilar Helix
antenna cannot be switched between RHCP to LHCP because for
RHCP the bifilar loops must be left hand wounded and for LHCP they
must be right hand wounded just the reverse of what happens with
a conventional helical antenna.

The only effect that can be obtained properly switching the bifilar loops
at feed point in a Quadrifilar Helix is to get the radiation pattern become
endfire or backfire as described in the AMSAT Journal May/June 2004
and so if you want to switch between RHCP to LHCP with Quadrifilar
Helix you need two antennas.

73" de

i8CVS Domenico

----- Original Message -----
From: "Norman W Osborne VE3CJE" <nwosborne at shaw.ca>
To: <amsat-bb at amsat.org>
Sent: Friday, November 17, 2006 5:09 PM
Subject: [amsat-bb] Comparison Quadrifiar verses TMP ll


> Just wondering, how the comparison of Texas Potato Mashers ll verses the
> Quadrifilar Helix
> for Leo's. Both with the ability to switch RHCP and LHCP
>
> Norman.
>
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