[RFI] need ideas on hunting down QRN-like noise source

[dj2001 at mn.rr.com]

I have the APC LS-700 and it's quiet.

Dale



>I recently found a modest-level signal on various HF bands,
>20 to 50 kHz apart.  I finally got annoyed with it enough to
>start flipping breakers in my house.  Finally got to the breaker
>for the shack, and low and behold, the noise *changed*
>when I hit that breaker -- it didn't go away, but it got less
>and sounded somewhat different.
>
>It turned out to be a Tripp-Lite UPS that I just bought
>for the shack computer (model OmniSmart 1050 PNP) --
>it was generating the noise, and when it lost power, it still
>generated noise, but was less and sounded different.
>My other UPS (Tripp-Lite BC Pro 850) does not appear
>to have this problem.
>
>Moral:  just because you turn even the main breaker off,
>doesn't mean that everything is really off.
>
>And if anyone has ideas on taming a noisy UPS,
>I'm all ears.
>
>--
>Dave NØRQ
>
>
>
>----- Original Message -----
>From: "Scott Ginsburg" <k1oa at comcast.net>
>To: <rfi at contesting.com>
>Sent: Monday, June 14, 2004 8:50 PM
>Subject: [RFI] need ideas on hunting down QRN-like noise source
>
>
>>
>>  I'm currently plagued with two sources of HF RFI, and for the
>>  moment am concentrating on locating one of them. Any help
>>  I can get from the RFI sleuths on the list would be greatly
>>  appreciated!
>>
>>  The noise in question showed up about a month ago, and appears
>>  as a combination of white noise and random, rapid static crashes.
>>  The static crashes, or bursts, sound a lot like heavy QRN.
>>
>>  It is typically the loudest on 14 MHz, and can be heard from 7-24 MHz
>>  when it's at its worst, with peaks on 14 MHz of 10 over S9. I hear no
>>  buzzing when listening on AM. My noise blanker has no effect.
>>
>>  Its presence can't be correlated with weather. I hear it on both wet
>>  and dry days, wind or no wind.
>>
>>  It seems to peak from a certain direction when I listen on my HF log
>>  periodic. I've driven the neighborhood streets (up to 2 mi away) with my
>>  706 and hamstick in the car and can hear what I think is the noise in
>>  certain locations, but never loud enough to be a "smoking gun". I
>>  verified it's not coming from my house, by killing power and listening
>>  in the driveway on my 706 to the noise.
>>
>>  Early morning is typically very quiet. At 6:30 AM local time I usually
>>  hear only silence, or a few weak bursts of noise which sound like the
>>  problem. It typically peaks by noon. I almost always hear it in the
>>  evening and at night.
>>
>>  Any hints anyone might have as to what a possible source might be or
>>  the best way to continue trying to track this down would be
>>  appreciated.
>>
>>                                                    73,
>>                                                    Scott, K1OA
>>
>>
>>  _______________________________________________
>>  RFI mailing list
>>  RFI at contesting.com
>>  http://lists.contesting.com/mailman/listinfo/rfi
>
>_______________________________________________
>RFI mailing list
>RFI at contesting.com
>http://lists.contesting.com/mailman/listinfo/rfi