Final resolution;
There were some power company workers replacing old wiring on local
poles and instead of calling, I asked them if they could replace the
light and they had an extra sensor which they did put in. That did
not help. I took a night video of the light and got ahold of a
portable AM radio and recorded the interference to the radio along
with the synchronized startup sequence of the light. It was pretty
ugly.
Took that to the Public utilities office this last Friday and asked
to talk to one of the PR folks. She watched and listened and said it
was pretty unplesant. As of Monday it was repaired and last night was
the first night in a very long time I didn't have that constant RFI
on my radio.
I think the video along with the audio made a good impression on her.
Gary
KA1J
P.S. Yes, High Pressure Sodium
> Many thanks to the on & off list replies to help me on this. I kept
> trying to hear this problem on the AM broadcast radio but when it was
> on 40M it was not showing up at all on the AM radio.
>
> I went on a snipe hunt & walked the neighborhood looking for anything
> that was an issue. The only thing I noticed was some kind of flicker
> on the street lights (only one street for a long way & I'm at the dead
> end of it). So I looked for it but all the lights were lit. I walked
> 1/4 mile & saw no unlit lights so I turned around and while walking
> back, saw a flicker again.
>
> I couldn't tell for sure but the flicker seemed to be coming from the
> last light which is close to my house. I went in, turned the tape
> recorder on & left the radio on to 7.000 and went upstairs to see the
> light & listen to tha AM radio. Sonofagun, the light was out and the
> AM radio showed nothing though the light was 70 feet away. The light
> lit and nothing on the AM radio so I marked the time,immediately went
> downstairs & listened to what was recorded & yup, that was it.
>
> I went out and waited for it to happen again (and recorded the 40M on
> the Ten-Tec again to co-ordinate events once again. The light went out
> and again I timed the sequence in the dark (one elephant, two elephant
> & so on) and about 38 seconds later the light switched itself on the
> light be it High pressure Sodium or Metal Halide, the prolonged firing
> sequence was the long sound and the 2-3 seconds at the end of that is
> when it sparked into life.
>
> I went back to the recording, checked it and yes, that was it.
> Problem solved. The thing is how the AM radio did not pick up a
> single thing but it was well over +20 when it was heard in the Ten-
> Tec on 40M.
>
> I am assuming that the frequency is that faulty ballast must be
> closer to 7Mhz than 1.6Mhz but perhaps if my radio was portable it
> would have made the difference if I were under the light when it went
> out. I suppose I could have moved my car under it & turned on AM but
> for it to be so powerful in the shack and not to show in the house AM
> radio was indeed a surprise,
>
> Calling the power company tomorrow.
>
> Again, thanks for those that replied!
>
> Gary
> KA1J
>
> > Hi,
> >
> > O'course it's always bad RFI but I'm stumped on this one (and I used
> > to think the dog fence down the street was the issue...
> >
> > Here goes; I live at the last house on a dead end with 1 mile worth
> > of trees to the north, 3/4 mile of trees and ocean to the East, 2
> > miles of trees and ocean to the west with a small airport about
> > three miles away. And there is the street leading in a straight line
> > to my house.
> >
> > Pristine, eh? Problem is there is an electric train Amtrak uses that
> > passes by frequently (there are 12' high Hurricane fences on both
> > sides of the track so hikers from one state park crossing the tracks
> > to the other won't get hit by the "silent" train. In addition, there
> > are power lines (not the really big ones) that intersect at the
> > corner of my 2 acre lot. But these are lines that carry the power to
> > a nearby island so they are not the normal residential variety.
> >
> > When it's quiet here radio wise, it's what you would expect and the
> > only bugger was 8 houses away there is a hidden dog fence that
> > splatters in the 160 meter range.
> >
> > Recently though something new has happened RFI wise at this QTH and
> > I'm pretty stymied as to what it is & what to do about it or who
> > even to complain to; the sound can be heard on the links I have
> > provided below:
> >
> > http://doctorgary.net/QRM-1.mp3
> > http://doctorgary.net/QRM-2.mp3
> >
> > The sound is intermittent but frequent. I asked my father to use his
> > icom with a scope to see what he could see and it is detectable from
> > the 1.6Mhz broadcast band through 18Mhz with the worst being around
> > 7Mhz. Perfectly regular pulses.
> >
> > I thought perhaps it was from something in the line so I
> > disconnected the antenna but the interference stopped. I set up a
> > remote receiving antenna alongside the salt marsh but the sound
> > comes in just as strong on that as it does on my Butternut Vertical,
> > as it does the Inverted V for 80M & 40M. It registers a solid S20 on
> > 40M and S6 on 80M but it is always the loudest sound I can hear and
> > the noise blanker in the Corsair does only a fair job of removing
> > it. The Omni V has a poor noise blanker.
> >
> > Can't imagine it will help much but here's an overhead of the house
> > from Google Earth http://doctorgary.net/QTH.jpg
> >
> > Finally I decided to run the remote antenna (small receiving loop)
> > to the corsair & via battery so there is no connection of any kind
> > to this gear and yes, the problem was the same on battery & an
> > antenna 300' from the house.
> >
> > So tonight I got tired of hearing it and started writing down the
> > times it started & stopped. I only did this for a half hour but I
> > discovered the RFI is almost always 38 seconds long and tapers off
> > and stops in about three seconds. For awhile it was coming almost
> > every 2 minutes but around 11PM it became less frequent, being two
> > times over the space of a half hour. I have noticed that the
> > interference is less in the late evening but this was the first time
> > I tried putting times to the occurrances.
> >
> > So those two recordings, they're the same for all practical purposes
> > only they were separated by two minutes.
> >
> >
> > Any ideas?
> >
> > Thanks!
> > Gary
> > KA1J
> > _______________________________________________
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> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
> >
>
>
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