From: Keith Wootten
Subject: Re: More on HF DF (or ADF)
User-Agent: Turnpike/6.02-U (<7r9OMDU2ooRJCQmjnYJxyjtHfm>)
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Date: Tue, 12 Nov 2002 13:13:53 +0000
NNTP-Posting-Date: Tue, 12 Nov 2002 13:14:09 GMT
Organization: ntl News Service
In message , Jim Weir
>There has been some discussion on this NG about how to detect the location of a
>transmitter in the HF region (80 and 40 meters is the subject of some interest
>here) using everything from a handheld radio's loopstick to a curtain
>will cover several dozen acres.
>Suppose, just suppose I wanted to fix a small, lightweight antenna in a single
>position and in some way figure out the direction of a distant signal relative
>to some known horizontal axis of the antenna.
Jim, http://www.uspto.gov/ (US Patent Office) is a useful resource.
Enter "radio direction finder" or similar in the patent search section -
you'll need to download a suitable viewer if you don't already have one,
the FAQ tells how and what. US patent 4,302,759 and 4,368,470 are
examples similar to what you want, but there are many more. This
particular patent uses two orthogonal loops with a whip and some phase
It never ceases to amaze me just what sort of obvious things can be
patented, along with their seemingly endless variations.
Extend surname and exorcise for e-mail.