|[AMRadio] Radio Noise, BPL?|
doxemf at aol.com
doxemf at aol.com
Tue Jul 15 02:39:20 EDT 2008
I went around inside the 4 story building and a bit outside using a
Radio Shack DX-390 but the RF gain control doesn't work for MW or LW
where the ferrite antenna is functional so only marginal D.F. ing was
done due to front end overload. But the noise does appear to be power
line radiated and from other places besides the Panel previously
The signal is so strong at 1230 that mixes heavily with the local 1KW
AM station at that Frq.
One thing that I could confirm is the perfect 10 KC spacing of the
harmonics? starting about the middle of the BC band and fairly
consistent in level right on up with a gradual drop in level to at
least 8 mhz. every 10kc. The strongest levels are in the B' cast band
but that might just be characteristic of the receiver since it switches
to the whip antenna above 1700kc. It is not really noticeable at 10
mhz. alongside WWV.
The signal looks like a square wave and gives very little zero beat
with the BFO engaged.
I won't contact the Electric company until I am sure where the source
Will use the old solid state Tandberg portable on Tuesday since the
ferrite antenna is functional up to about 5 mhz
and the off axis nulls are real good. The DX-390 has weak nulling and
Have got to get the Spectrum Analyzer running. Have yet to determine
the fundamental frq. or even if there is one.
It was real strong this evening/night making it near impossible to even
hear the strongest stations on 3885. due to the 3880/90 noise peak
being in both the lower and upper pass band edge.
I will find out where this is coming from and put a stop to it somehow
It is certainly strong enough to exceed the FCC spec for spurious
emissions and could be considered as interfering with licensed services.
From: Jim Miller WB5OXQ in Waco <wb5oxq at grandecom.net>
To: Discussion of AM Radio in the Amateur Service
<amradio at mailman.qth.net>
Sent: Tues, 15 Jul 2008 12:16 am
Subject: Re: [AMRadio] Radio Noise, BPL?
That is indeed strange. I can think of wireless intercoms, wireless
controls etc that use the ac line for their carrier usually at low
frequencies I believe. I really cannot think of anything else right
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