[RFI] Re: Disconnecting from Internet

Spammers Must Die wsanders1 at yahoo.com
Tue Apr 29 10:40:07 EDT 2003

I don't know whether you are talking about a DSL or dialup connection
with internal or external modem but the phone line is not the only
place where RF can get into a system. Also, with ladder line, the
feedline length can be critical.

I would suggest moving the SGC tuner close to the antenna itself and
eliminating the ladder line as much as possible. I didn't realize the
SGC tuners had balanced outputs, either - it may be designed only to
work into a long wire, in which case you may get better results moving
the tuner to one end of the antenna (coax has low losses at HF so a 100
foot run shouldn't be a big deal) and running a long wire all the way.

I have DSL with a mix of wireless and wired conenctions. The antenna is
a 140-ft dipole fed with ladder line. I used to knock my wireless
connection off the air on 20m, until I added 15 feet to my feedline
(this cured all my RF in the shack problems and let me tune up on the
80 and 10 CW bands, too.) Since I'm taking the Element 4 exam soon, I
should know why this worked :-).

Also, my wired ethernet connections are the main source of RFI from my
netwoking equipment. I have to turn the stuff off to work some
frequencies. It is possible to buy shielded Cat-5 cables, and as soon
as I find a source I'll upgrade. For now, ferrite chokes on the
ethernet cables help. I have a Speedstream 5100 DSL modem and Linksys
BEFW11S4 WAP/router which are pretty quiet except for the ethernet.

-Wiley KF6IIU (who's been waiting 3 weeks for PG&E to call him back
about the power pole across the street that is radiating S3 to S9).

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