[CQ-Contest] RFI Issue

I4UFH i4ufh at libero.it
Mon Aug 29 16:23:20 EDT 2005

Did you have a IC2KL amp connected to your 756PROII ?

I had noticed same problem, with my 2KL connected to the 781 and switched

It was really difficult to find it, was the Switch power supply of the 2KL
with some caps with high ESR. replacing them and added caps on the power
wire cable, fixed the problem.

73 de Fabio I4UFH

----- Original Message -----
From: "Joe Stepansky" <kq3f at comcast.net>
To: <cq-contest at contesting.com>
Sent: Sunday, August 28, 2005 7:11 PM
Subject: [CQ-Contest] RFI Issue

> I hope the group doesn't mind me taking a little bandwidth on this, but
> I've been searching for a solution to an RFI for months to no avail.  If
> anyone knows what this might be, or has seen this before, I'll be in your
> eternal debt.  It's my luck that this is roughly in the direction of
> Since about April I've had RFI issues on 20 through 10 meters, but loudest
> on 15.  I have an IC756PROII, and on the scope it appears to be a series
> spikes moving right to left (seems to be a switching power
> supply?...unstable and decreasing frequency).  When it's just the spikes
> the noise has a grinding sound on SSB.  But there's another
> component.  This is a series of little blobs moving very quickly left to
> right on the scope, which I take to mean unstable and increasing
> frequency).  This is accompanied by a rushing water sound (best I can
> describe it).
> Here's another kicker....it NEVER occurs during rain.  Never.  The local
> power company has now been out four times trying to find this thing and
> have tightened the hardware on a number of poles, but the noise
> persists.  I'm convinced it's not the power company.
> To give you an example of the sequence, today is a good example.  It
> last night/this morning, no noise.  Then the sun came out about 11 AM, the
> little spikes appeared, moving right to left on the scope.  The the little
> blobs appear.  This goes on for about an hour, then it's only the spikes
> and then the noise (and spikes) abruptly stops.  Then, the little spikes
> (and grinding noise) appear sporadically for maybe 2-3 seconds at a time.
> I've never seen the noise appear at night,  And though it never appears
> when it's raining or damp, it's not there all the time when the sun's out,
> either.
> I've pegged the direction at 60 degrees, and have drawn a line with that
> heading from my QTH on the map I use for APRS.  I've driven that way a
> number of times, but nothing.  I've often come home to find the noise
> so it's possible I was chasing a ghost.  Oh, I've shut off breakers in my
> house and it doesn't matter (besides the house is not at 60 degrees, but
> who knows?)
> My wife was all set to drive me around this afternoon when the noise, once
> again, stopped.
> Does anyone have a clue what this might be?  If you got this far, thanks
> for reading.
> 73, Joe KQ3F
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