Re: Turnstile antennas for mode A

[John W Wilson <z004391b@xxxxxxxxxxxxx>]

You might try an eggbeater antenna. Circular polarization straight up and 
horizontal polarization to the horizons.


John W. Wilson, KN4HX
z004391b@bcfreenet.seflin.lib.fl.us


On Sat, 11 Apr 1998, Robert D. Brown wrote:

> Ladies and gentlemen of AMSAT,
> 
> I am currently installing a ten-meter dipole in my attic for, among other
> things, mode A work.  I was wondering if the "turnstile" for 10m receive is
> worth the trouble (not MUCH trouble but if it doesn't buy me anything i'll
> save the coax)?  Will this configuration significantly improve receive over
> a standard dipole?  For terrestrial work, what will be the impact on transmit?
> 
> Finally, a question for the RF-impaired:  Davidoff's Handbook calls for a
> 1/4 wave phase delay line between the two turnstile dipoles- a 90 ohm
> line...why 90 ohm and how critical is this (ie would 50 or 75 ohm work?
> Not that I have a problem buying 10 feet of coax... just curious on the
> sensitivity of the application)?
> 
> Thanks for the help,
> 
> Rob WB2DVX
> 
> PS  Other than listening to a couple of the RS birds on a shortwave I have
> NO experience working any of the satellites- this will be my first foray.
> 
>