[R-390] Re: Noise...(somewhat long)...

[Kenneth G. Gordon]

> As to the odd interference, on my early to middle
> afternoon listening, at a large freq area, from aprox.
> 14mhz to 18 mhz I am getting an impulse type noise at
> aprox 5.2 times a sec that sounds like you would get
> from an engine running, but I have taken a small
> handheld all over within a few miles, and can't find
> anything. It never gets louder or softer from moving
> around in the area...(As I live almost on the water, I
> guess it could be on the other side, in areas it is
> difficult to get to, like a few factorys with the
> buildings a mile behind the no access gates....)
> 
> Anyone know what else I could look for? I am in Panama
> City FL. area.

I have been reading your e-mail describing this problem. Although 
your e-mails aren't totally clear, to me at least, when you are 
describing what is going on, I think I can make some suggestions:

1) First of all, you must determine positively that the noise isn't 
coming from something inside your house or on your property.

So, with a battery operated portable radio tuned to the noise go to 
your breaker or fuse panel and turn off breakers or remove fuses 
one at a time, leaving them off when you do the next one, until ALL 
are off, or until you determine that one of the fuses or breakers 
eliminates the noise. If, when turning off a breaker, the noise goes 
completely away, trace that out till you find the source. If you still 
have noise, even if it is weaker, go to the next step.

2)  Get a portable radio of some sort with a built-in loopstick 
antenna. If you choose a multi-band portable radio, keep in mind 
that the loop-stick is usually only connected to the input stage on 
the standard AM broadcast band.  The rod antenna is the used for 
the SW bands and possibly for the FM band, so don't use either 
SW bands or FM band.

The radiation pattern for a loop stick is broadside to the loop-stick 
(in most cases), and there is a fairly sharp null off the ends. You 
can determine which direction the null is pointing by tuning in a 
fairly strong local station, which you know the direction to, and 
turning the radio around on its center axis until that station is 
nulled. You may have to open the radio up to see what the 
orientation of the loop is. In some radios it is horizontal near the top 
under the handle. In others it is vertical to the radio.

Tune the radio to a quiet spot in the band (best to do this during the 
day) and, then, starting in one corner of your property, swing the 
radio back and forth with the loop HORIZONTAL until you get a null 
on the noise. The length of the loop will be pointing AT the noise 
source. Mark the direction somehow. I use a crude, hand-drawn 
map of my place.  Walk to another corner and repeat. Do this for 
all 4 corners. IFF the noise is on your property, you should be able 
to get a pretty good idea of where it is coming from.

3) If the results of this "triangulation" technique are either 
inconclusive, or you find them pointing TO A POINT off your 
property, you will have to take things a step further.

4) If you determine either that the noise is coming from someplace 
OFF your property, or are unable to determine exactly where it is 
coming from, visit your neighbors and ask them if they have started 
experiencing noise or static on either their radio or their TV sets 
recently. Tell them that you are trying to track it down and any help 
they give you would help both you and them.

At this point, I would most strongly suspect a problem with the 
power company's equipment. Power companies use aluminum wire 
to connect from the transformer to your house in most cases, and 
this is notorious for failing.

In fact, after reading what you told us, I immediately suspected that 
the connections from the power line to your panel AT THE PANEL, 
or the connections at the transformer that feeds your house, or the 
connections from the transformer to the main power line, are loose 
and arcing. To fix this, you will have to call your power company, 
and be REALLY insistent that they come take a look. DO NOT try 
to fix this yourself unless you are a licensed electrician.

I know of at least one incident wherein when the power company 
opened the pad-mounted transformer door, they found a puddle of 
molten aluminum on the floor.

In my own case, I had been troubled with terrible noise for a 
number of years. It would come and go, pulse, get louder and 
softer. I tried to triangulate it and I found several nulls up and down 
the power line which follows the street in front of our home, yet the 
strongest noise was right at our panel. When I turned ALL the 
breakers off, the noise diminshed, but was still audible.

A few months ago, in the process of adding a new bedroom, we 
had the feed from the pole to our house, the downlead from the 
roof to the meter base, the feed from the meter base to our panel, 
and the complete panel replaced with all new parts.

We discovered that the cable from the meter base to the panel, 
AND that from the meter base to the roof jack, AND that from the 
roof-jack to the pole, ALL of which was aluminum, had never been 
installed properly, or had deteriorated with age. There were burned 
or arcing marks under the sealant in several places. 

Now my noise is completely gone and I can listen in blessed 
silence.

Let us know if this helps.

Ken Gordon W7EKB