[RFI] Power line or ? noise
dana.roode at gmail.com
Wed Apr 19 10:54:52 EDT 2006
I got busy after sending my note last Sunday about my RFI woes, but I
would like to thank everyone who has responded with their ideas and/or
"reality checks." I agree, my situation is far from unworkable, and I
am able to make many contacts on all bands despite my noise. I am
sorry to hear about the more severe noise problems some of you are
Noise was one of the reasons I helped my brother purchase a home 80
miles away in the desert - when we first setup a station out there it
was very quiet. The noise has built up in recent years.
Someone asked what the noise level was before SCE came out and fixed a
bunch of problems - I honestly don't remember S meter readings (I was
using a different receiver), but it was a good deal worse than it is
now and in different directions. I agree that SCE has done very well
for me thus far in dealing with noise. Larry Johnson was out on the
first day he and I were both available after I called SCE. He spent
at least 4 hours tracking down noise sources. The crew took awhile to
come out, but they were out, and they fixed everything Larry found.
Really quite excellent service.
I've got some good information to go on now, and I'm going to do some
driving around to help locate the current noise source. I realized my
ignition noise is not bad above 21 mhz, and it sounds like 50mhz might
be the best frequency to get an idea of where the noise is strongest.
My IC706 has 144 and 440 as well, so I will move up the band as I get
near the source and see if I can track it down to a few suspect poles
in the direction my Yagi thinks its the strongest. I've got a small
440mhz yagi and a portable receiver that may help as well.
If I can locate some suspect poles, I'll call Larry back and see what
he can do for me.
More later, and thanks again,
On 4/16/06, Dana Roode <dana.roode at gmail.com> wrote:
> RFI Folk,
> I have a station located at a house I own with my brother out in the
> California high desert - its a residential area, but on 2.5 acre lots.
> The nearest houses to ours are about 500' away (lots are 300' x
> I've had a bunch of noise problems that I have been trying to sort
> out. Last summer I contacted Southern California Edison (SCE) who
> sent their RFI guy out (Larry Johnson). Larry did a thorough check of
> the electrical poles within about 1000' or more of our house and found
> 7 noise sources that he reported. It took quite awhile for the SCE
> crew to come out, but they did in November. Afterwards, the nature of
> the noise I was hearing seemed to change, but there was still plenty
> of it.
> Larry came back out and checked the poles again and reported they were
> all clean, leaving me to think it was a problem with one of my close
> neighbors, but now I'm not so sure. Let me tell you all about what I
> hear and see if you have any thoughts about what I am dealing with.
> On my TS480 with the pre-amp on, the noise peaks at about S6 on the
> meter to the east. With the preamp off it is s0 with spikes up to
> s3-4 every few seconds. It sounds like garden-variety atmospheric
> noise but stronger with some sputtering interlaced. The noise is
> broad and fairly strong from just south of east, through north to just
> south of west. The power lines are closest to my house on the east,
> north and west, so it seems like the noise may be propagating over
> When I stand at the eastern part of our property with a portal SW
> receiver and a loop antenna, I'm not able to hear the noise much at
> all, and can't get any direction on it. My Yagi at 65' picks it up
> quite well. I have a 40m four square - the noise is clearly stronger
> NE and SE than it is NW and SW.
> When Larry was out he hooked up his receiver-scope to my antenna - the
> goal was to get a picture of the noise to make sure he was chasing the
> right one. However, it was never strong enough to show up on his
> I've done the standard thing of turning everything off in the house to
> verify it wasn't coming from my stuff. I do have a problem with my
> Internet service, which is wireless - it creates a pretty strong
> signal I've tracked down on 6 meters and 15 meters. I've replaced my
> Ethernet cable with shielded cable and added ferrites but haven't been
> able to solve it. However, the noise I am talking about above is not
> the same as I've turned the Internet equipment off while I've been
> tracking it down. The network equipment does not seem to cause
> problems below 21mhz and only peaks when I point my antennas toward
> the house. It also is frequency dependent, peaking every couple of
> hundred Khz or so.
> Some random questions for you:
> * Is it all in my head :-) ? I turn the pre-amp off, and its not bad.
> Larry's device couldn't even hear it, nor my portable receiver.
> Maybe I should just live with it. (I'm thinking not, but had to ask).
> My noise at my home in Irvine is much worse, however, but I gave up
> on that years ago (being surrounded by houses on 1/8 acre lots).
> * How far might this noise be from the house? Its not bad at all
> 15meters and up, its mostly a problem 20m and down. Could this be a
> half-mile away? A mile? Perhaps I or SCE needs to check poles
> further away.
> * I have an AR8000 portable receiver and a 4 element 2 meter beam - is
> this adequate to check poles out to see if they are noisey? Would it
> be better to do it on 220 or 440 (Ive got small beams for those bands
> too I could use). Use SSB and the Smeter or AM and audio level?
> * Would it be helpful to hear samples? I have some .wav files I could
> upload to a web site.
> * Ideally, I'd like to hear the noise on my portable receiver with a
> loop and track it down starting at my property. Otherwise, I need to
> wander around until I hear a noise and hope its the right one. Any
> thoughts on this?
> * I have a mobile rig in my Ford Expedition and can drive around
> looking for noise. However, the Ford has bad ignition noise so I have
> to stop and turn off the engine to really hear it. Is it helpful to
> use a mobile rig and a vertical whip like this to track down the
> noise, or am I better off on foot?
> * Does it seem likely the noise is coming from a neighbor's house even
> though I can't hear it without my yagi at 65'? My yagi is located on
> the east side of the property about 150' from our house and perhaps
> 300' from the neighbor's.
> * Is it useful to listen after a rain storm to see if the noise
> changed? The thinking being that if it doesn't change (get weaker)
> its more likely to be in a house than a problem on a SCE pole? I
> don't recall the noise changing much due to the weather, time of day,
> or anything else. Seems to be pretty solid.
> Thanks for reading my stream of consciousness post, any thoughts would
> be welcome.
> Dana K6NR
More information about the RFI