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Re: [RFI] RFI Direction Finding

To: "'Jim P'" <jvpoll@dallas.net>,"'Paul Christensen'" <w9ac@arrl.net>, <rfi@contesting.com>
Subject: Re: [RFI] RFI Direction Finding
From: "Ed -K0iL" <eedwards@tconl.com>
Date: Sat, 18 Feb 2006 08:50:00 -0600
List-post: <mailto:rfi@contesting.com>
The FM broadcast wouldn't be affect on an FM radio since noise is
"Amplitude" in nature.  FM rcvrs won't pick them up (usually, although some
rcvrs may).

Most powerline noise sources, when you are in the neighborhood, do emit into
VHF high-band real nice and sometimes even lower UHF portion locally if you
have a sensitive enough rcvr at those freqs.  I am not referring to ham
bands here, just generic VHF (30-300Mhz) & UHF (300-3000).  At work we use
somewhere around 250-300Mhz and usually have to start turning the gain down
when we get it down to the last couple of poles to figure out which one it
is.  Then we switch to ultrasonic to confirm the results and determine which
hardware is the offender.  

73, de ed -K0iL

-----Original Message-----
From: Jim P [mailto:jvpoll@dallas.net] 

This WORST HF noise source ever didn't make much of a fuss
on the FM Broadcast band either when close; no wonder the
other ham didn't find it in the 2M VHF spectrum.

> Track it on the highest freq at which you can rcv it moving to higher
> the stronger it gets.  You'll notice standing wave peaks and nulls as you
> approach the source--ignore those peaks looking for an overall stronger
> stronger peaking.

Very good advice.

I love those sources that radiate into 450 MHz area where I
can use a 7-element Yagi and DF right to the house or
pole. Those are kinda rare though, although shorted
doorbell transformers and arcing 'dust' filters are easy
to DF this way.

Jim P  -- WB5WPA --

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