[CW] "Magic" lamp QRM

[Mike Hyder -N4NT-]

Hi, Don--

That is a pretty common problem.  We just replace the electronics with a
switch.  Funny story about those things was told my John, W4SK.  He was
operating one night in his basement when his neighbor came over and was
banging frantically on their front door.  John's new touch-lamps beside his
sofa were cycling from off to dim to medium to bright and back to off with
every element of every character.  From his neighbor's house it looked like
John's house was afire.

Here is a link to my touch-lamp trouble as well as some other noise sources:

http://www.qsl.net/n4tn/noise.html

73, Mike N4NT

----- Original Message -----
From: "Donald Chester" <k4kyv@hotmail.com>
To: <cw@mailman.qth.net>
Sent: Saturday, October 05, 2002 6:10 PM
Subject: [CW] "Magic" lamp QRM

Subject: "Magic" lamp QRM
Body of Message:

I recently noticed a very rough, broad signal that wipes out 30-khz portions
of the spectrum from the middle of the broadcast
band through 10 m. It is especially bad on 160 and 80m. I did a little
sniffing with a portable radio and found the source to be a
table lamp my daughter just bought. The thing doesn't have a conventional
switch, but a metal base, and you turn in on and off
by touching the base with your hand. The thing must have some sort of
oscillator somewhere in the 450 kHz range, and works by
detuning the oscillator when you touch it. What kind of rubbish is someone
going to think of next to garbage up the radio
spectrum!

I have never seen one of these things before. Is this a novelty or
speciality item, or is this the way all table lamps are made these
days? (It has probably been 20 years since any of us bought a new table
lamp.) Surely, this must fall under Part 15, so I
wonder why the FCC even allows those things to be sold on the market. It is
far worse than my computer monitor, and I had thought that was already bad
enough. I'm surprised the AM broadcast industry isn't raising bloody hell
about stuff like this. I can't imagine polluting the rf spectrum with
rubbish because someone might be too lazy to flip a switch on a table lamp.

I'm wondering if anyone else has had problems with interference from those
things, and what might be the simplest solution. I tried an in-line rf
filter, but it made no improvement whatever. Unless there is something
simple to by-pass, the only solution I can think of is to go into the thing,
rip out the electronics, and mount a conventional swith with a knob on the
base. I'd like to hear from anyone who has successfully fixed one of these
things some way other than  clip-leading the power cord across the HV
terminals of the plate transformer and throwing the big switch.

Don K4KYV