Topband:mode separation...small stndx oppty

Brad Rehm brehm at ptitest.com
Fri Apr 23 18:47:21 EDT 2004


"...One of them suggested
that DSL might be responsible for some trash on 160. Any thoughts on
this?  I don't have DSL myself -- I use a cable modem, with its own
(much higher frequency) set of problems."

Jim K9YC

DSL routers or the DSL service on the outside phone lines might be the
source of the noise you're hearing.  On the other hand, I've heard of
interference from DSL on the higher HF bands and of hams who've been
able to tell when they're in DSL neighborhoods by listing to their
mobile FM transceivers.  But I haven't run into any complaints about
DSL noise on 160.

You might want to look for noisy switching power supplies in your
house or in a neighbor's house.  Many of these operate in the 50-100
kHz range and can generate a lot of hash at the low end of the HF
spectrum.  It's easier to suppress the high-end noise, and emissions
below 5 MHz can be very close to the FCC Part 15 limit.  The result is
that they can be very bad neighbors for 160 ops.  Your friend might be
hearing another power supply at his QTH--not the same source you're
hearing.

73,
Brad, KV5V



More information about the Topband mailing list