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[TowerTalk] Static interference

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Subject: [TowerTalk] Static interference
From: (
Date: Fri, 21 Mar 1997 11:13:31 -0600
Gene wrote: 
>It tends to shift around but seems to remain about 20 
>to 40 khz wide all throughout HF.  The static appears at 
>about every 150khz from 2mhz clear through 20mhz. 
Hi Gene,  
What you're hearing is the RF emissions from the free running oscillator found 
in a cheap touch controlled lamp.  I'll bet you a new QRO amplifier on it!  
They're made in Taiwan and are not UL listed.  Some are worse than others 
depending on age.  As long as they're plugged in they'll generate noise up to 
2 or 3 blocks away!  I have tracked down 4 nearby lamps in my neighborhood in 
last 5 years. 
If the signal's really strong, you may be able to trigger the on/off or 3-way 
level control.  I was able to do this to a new neighbor's lamp.  The day they 
moved in I was at the rig and actually heard them plug it in.  I tuned to the 
bottum edge of one of the 40Khz wide pulsations and keyed up on CW briefly.  
The pulsation shifted up in frequency!!!  So I retuned and keyed again.  It 
shifted again!  I repeated the whole sequence a third time with same result.  
On the forth transmission it shifted way down back where it started.  
Definitely a I continued to cycle the lamp like this for a few 
minutes IDing every now & then.  Suddenly I heard them unplug it!!  Then they 
plugged it back in so I very deliberatley and with rhythm cycled it through 
the levels and off again.  They'd turn it back on and I'd turn it off again!  
Boy was this fun!!  They finally unplugged it and left it unplugged. 
...until the next day.  When I got home there it was again!!  So I waited 
awhile before playing the "Haunted Lamp" game again.  Near bedtime I struck up 
another conversation with the lamp.  In no time at all it was unplugged again. 
 I never heard from this lamp again!  This may not be the best solution, 
however, especially if they figure out your causing the lamp to go on & off. 
In another case, I was to far away to trigger the lamp. (I hv no amplifier.)  
So after locating the house I contacted the young woman that lives there and 
explained what the situation was.  I tried the "Your lamp must be 
malfunctioning and might be a fire hazard" story, but it didn't seem to phase 
her.  She said they were too pretty to get rid off!  She had two of these RF 
monsters, one on each night stand.  So I asked if I might take one in to get 
it repaired. 
I researched who makes the lamps and who sells them here in Omaha.  I then 
contacted Imports Intl. here in Omaha and bought a new controller for $6.00 
and installed it.  Only a slight reduction in noise.  Interestingly, I found 
one AC outlet in my kitchen which didn't propagate any noise at all!!  Might 
be because of the GFI on that outlet or wiring configuration.  I then tried 
some of the cures found in the ARRL's RF Interference book (GREAT BOOK!) and  
in some old QSTs.  You can get this information via the ARRL e-mail server by 
sending an email with 
in the text to , or if you'll send me your e-mail address, 
I'll send it to you direct.  Also, if you call the ARRL they'll send you 
reprints of Hints & Kinks and Technical Cooresponance dealing with these 
lamps.  I wrote up my experiences and sent it in to QST, but they said they 
couldn't publish it because they said didn't want to promote my "Haunted Lamp" 
method as a solution.  But Al Brogdon, K3KMO, sure thought it was real funny 
and wrote me a nice letter relating an RFI story of his own from his college 
I was able to clean up one of the young woman's lamps to a tolerable level.  
While the other lamp was still annoying when on low or high level only!  I 
asked her to use only the mid-level setting if possible, but she seemed to 
like to use the low level for mood lighting always after about 1am or 2am.  
She was a young single woman after all ;^)... If she only new how little 
privacy she had with these lamps.  She has since gotten rid of both lamps to 
my delite!  Now what can I do about my other neighbors new RF/wireless fence 
for his German Shepherd.  The poor dog is going to hate contest weekends! 
de ed 
-.-. --.-  -.. -..-   -.-. --.-   -.. .   -.- ----- .. .-..   -.- 
Eddie Jay Edwards                       E-mail: 
P.O. Box 375                             Amateur Radio Call: K0IL 
Elkhorn, NE  68022-0375       AK-SAR-BEN ARC Past-President, 1996 
Visit Ak-Sar-Ben ARC home page at URL> 
.-- .... -.--  .-.  ..-  .-. . .- -.. .. -. --.  - .... .. ...?;^) 

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