From: "Mike Dennison" <mike.dennison@rsgb.org.uk>
To: rsgb_lf_group@blacksheep.org
Date: Tue, 23 May 2000 13:14:36 +0100
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Subject: Re: LF: Re: Re: Morse tones / filters etc.
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> In message <Pine.GSO.3.95.1000522110818.17635D-100000@oso.slonet.org>,
> Clifford Buttschardt <cbuttsch@slonet.org> writes >Interesting observation
> on real time listening on LF.  When I was at sea >as a radio officer I
> arranged two receivers one vertical and the other >horizontal using the
> longwire 500 kHz antenna tuned to the same frequency >within one hertz. 
> Then by using two headphones, each arranged so that >opposite ears
> listened to opposite polarizations, results were simply >amazing! 

M.J.Powell wrote:
> I did something vaguely similar with 6m SSB, but I switched by hand a
> vertical and a horizontal antenna into the receiver. Fades were virtually
> eliminated. Showing I think that there was a lot of polarisation rotation
> on the incoming signals, but at LF?
> 

This is a variation on the well-known technique of diversity 
reception - which is what the old AR88D receiver was for (D for 
diversity!) - used by commercial HF fixed stations for many years. 


Mike, G3XDV (IO91VT)
http://www.dennison.demon.co.uk/activity.htm