From: John Woodgate
Subject: Re: Alan Blumlein site
Date: Mon, 16 Sep 2002 21:20:09 +0100
Organization: JMWA Electronics Consultancy
Reply-To: John Woodgate
NNTP-Posting-Date: Mon, 16 Sep 2002 21:26:25 +0000 (UTC)
X-Newsreader: Turnpike (32) Version 4.01 <5Z8C9wtxbnpWyFnyfFzqmVF739>
I read in sci.electronics.design that Jack Smith
wrote (in ) about 'Alan
Blumlein site', on Mon, 16 Sep 2002:
>I had a chance to dig out my copy of "The Wizard War" (R. V. Jones),
>and refreshed my recollection of his discussions.
"Most Secret War" in Britain.
>This technique was well known, I believe, before WW II, in the form of
>the LF A/N beacons. One antenna modulated with morse A (dot-dash) and
>the other antenna with morse N (dash-dot); when flying down the
>equal-signal locus, steady tone. To one side, hear the A or the N.
>These were in the 190-535 KHz range, formed from two "figure 8"
>antennas. See http://www.navfltsm.addr.com/ndb-nav-history.htm for a
>nice illustration. The A/N blend point provided a sharp 3.5 degree
>"beamwidth," something that would require an antenna size measured in
>miles if done with conventional techniques.
That is probably what made me think that the WW2 systems used 1 MHz or
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
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