Topband: 160m noise

[Joseph Dube]

I had a similar experience with a brand new APC UPS for my computer. The
switching supply that recharges the battery was producing strong birdies on
just about every , worst on 160 meters. Strange thing though this was right
out of the box!!!!!!!! The unit was taken back to Staples and was exchanged
without question.  I guess they have seen this problem before.

Joe KK4TR


----- Original Message ----- 
From: "Bill Tippett" <btippett at alum.mit.edu>
To: <topband at contesting.com>
Sent: Tuesday, November 09, 2004 7:02 AM
Subject: Topband: 160m noise


> Ni6T wrote:
>  >I am also hearing that many new computer systems have power supplies in
> which the line filter component locations on the board are jumpered and
that
> lower-rated, cheaper parts--such as lower-current rectifiers-- are being
> substituted for beefier parts. These computers are both radiating noise
and
> failing at a high rate. Gee, what a surprise!
>
>          I recently had first-hand experience with this.  When TX9 started
> up on
> Topband on October 16, I had an S8 birdie exactly on his frequency 1826.5.
I
> don't have very many close neighbors, but do have one about 1000' away to
the
> Northwest.  I walked around with my Sony 2010 and was able to faintly hear
the
> noise as I got close to my neighbor's house.  I left a message on their
phone
> and later the owner gave permission to walk around the house even though
> nobody
> was at home that day.  Sure enough, I found the noise was strongest from
the
> center of their house.  I called back and they said it would be OK to come
back
> and locate the noise source when someone was home, but they were going to
be
> away several days.
>
>          Fortunately the next day, when TX9 had a very good signal, the
birdie
> had drifted to 1824.0, and I was able to work him with no problem.  Had
that
> birdie not drifted, I would have been completely unable to copy him on
1826.5.
>
>          To make a long story short, the problem was a switching power
> supply in
> a new white box computer they had purchased locally.  Rather than dig into
it
> myself, I simply took it back to the dealer along with my Sony 2010 and
> demonstrated the problem.  While I waited, they swapped power supplies and
> the problem was gone.  This was all done under warranty since the computer
> was brand new.
>
>          Unfortunately I have several other much weaker birdies I have not
> been
> able to locate.  The farther they are away, the weaker they are and also
much
> harder to locate because of the distance to be covered to find them.  I
> believe this is becoming a major problem at my location and there is
really
> not much I can do about it except identify each source myself and then fix
> it.
> It's a shame that the FCC is allowing Part 15 devices like these switching
> power supplies to be put on the market.
>
>          I should go back to the computer dealer, get the power supply's
model
> number and manufacturer, and file a complaint with the FCC to send a
message
> to the manufacturer.  At least Riley Hollingsworth seems to be favorably
> inclined to take action on power line interference and electric fencers.
>
>                                                  73,  Bill W4ZV
>


----------------------------------------------------------------------------
----


> _______________________________________________
> Topband mailing list
> Topband at contesting.com
> http://lists.contesting.com/mailman/listinfo/topband
>


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.789 / Virus Database: 534 - Release Date: 11/7/04