Topband: 160m noise

[Garry Shapiro]

Topbanders:

I emailed the Reflector on 3 November asking for inputs re my discovery that
my Linksys BEFSR41 Router/Switch was radiating copious amounts of RF on
topband, apparently through the CAT 5 cables. I discovered this after
cruising the neighborhood with a car-mounted modified Loran loop and finding
that the biggest noise source was apparently in my own shack.

I received a bunch of responses to my original email, and I first would like
to thank those topbanders who responded--some of the information received
was extremely helpful:

* Dave, AB7E
* Tod, K0TO
* Larry, W7IUV
* Rog, K9RB
* Marc, ON4MA
* Mike, W5JR
* Tom, N5TW
* Hardy, N7RT

Thse responses ranged from commisseration to a wide range of similar
experiences with both Linksys and other systems, wired and wireless, on 160,
HF, VHF and even UHF. It seems that manufacturers are slapping Part 15 Class
B compliance labels on equipment which is not even close to compliance. Gee,
what a surprise!

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!

One respondent to my email suggested I Google "Linksys+noise", which I did.
What a revelation! Ten pages of Google references, indicating not only
longstanding and widespread awareness of this issue in the computer and
radio communities, but the intransigent indifference of the manufacturers
and the FCC. One fellow has had a complaint in with FCC for three years,
with no action. Gee, what a surprise! Other respondents indicated that
Linksys is not the only offender, either.

The Linksys box is plastic, with no conductive spray within, hence no
shielding. That and the unearthed string of complaints suggested
unambiguously that it was time to remove that product from my shack. How a
manufacturer has the gall to claim Part 15 compliance for such a device is
beyond me. And the fact that their "technical support" monkeys played it
dumb infuriates me, as does the apparent indifference of FCC.

On the advice of Paul, W6WA, a resident computer system guru for a large
Silicon Valley semiconductor company, I purchased a remanufactured Netgear
FR114P Firewall/Router via PriceGrabber for about $40. The unit arrived the
next day and was installed. It's in a steel box, is apparently well-shielded
and it's as quiet as a rock on 160. (I then had a problem talking to my
networked HP printer, which Paul quickly identified as due to the slightly
different IP numbers used by the Netgear--the print server address was
incompatible. It was a simple matter to change the numbers for the Netgear
box to match.)

One of my respondents warned that he had tried both Linksys and Netgear
without satisfaction and had settled on Belkin, so YMMV--this Netgear
product appears to work for me.

It is curious that the Linksys problem was only noticed after about three
years of use. It may have to do with the recent reworking of my ADSL
service, which replaced a Fujitsu modem with a Wesstel. I presume the
modulation scheme--I know of two systems in use--- changed.

Garry, NI6T