Yes, I suspected that it was part of the cable system.
I get S9 "powerline like" noise on HF all the way up through (and past
I suppose) 432Mhz. Sometimes the NB will knock it down, but not
always. The noise only appears when temps get above about 80 deg or
so. As temps rise, the noise gets stronger and more constant. Once
temps hit 85 or 90 degrees the noise is constant and S9 on 6 meters.
It goes away after sundown. The noise DEFINITELY came from this pole.
I just don't know if the noise came from one of these little boxes.
I DF'd the noise several times with a portable 432MHz radio and 5
element arrow yagi. A PG&E guy heard it while on the street in front
of my house, but by the time he went into my back yard to DF it to a
pole the noise went away. This was on a day that wasn't all that hot.
If the noise doesn't come from one of these boxes, then it sure is an
interesting co-incidence that one of these boxes blew on the very same
pole I reported to PG&E 1 month ago. Maybe it is a coincidence. Next
time temps get up to 90 degrees I guess I'll know whether it was this
box or not :-) Either way, PG&E is supposed to come out and fix this
pole (and another about 1 block away) regardless.
On 5/30/07, Roger D Johnson <n1rj@roadrunner.com> wrote:
> Kelly Johnson wrote:
> > Can anyone tell me what these little black boxes attached to powerline
> > poles around my house are? I suspect that one of them is a source of
> > RFI.
> >
> > Here's a link to pictures of the black boxes. They are about the size
> > of a shoebox with a cone on each end and wires running into the cones
> > on each end. The boxes are mounted on the wires close to the power
> > pole.
> >
> > http://www.kellyandshari.com/gallery/album18
> >
> > I reported a noisy pole to PG&E 1 month ago. The noise is only there
> > when outdoor temps go above about 80 or 85 degrees. A PG&E consultant
> > came out and heard the noise, but it went away before he could DF the
> > pole. I told him what pole it was based on my DFing. Last weekend,
> > something on that very pole blew up. It looks like one of these black
> > boxes. I'm hoping this solves my RFI problem :-) I won't know until
> > temps get hot again. In the meantime, I'm just curious what these
> > black boxes are for. The power went off for a second when we heard
> > the big "bang" from that pole, but went right back on. Nothing else
> > is out. None of the neighbors have reported a problem. I'm wondering
> > if these are cable boxes. Anyone know?
> > _______________________________________________
> > RFI mailing list
> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
> >
> I'm pretty sure they are amplifiers for the cable system. They normally
> don't cause any problems. What type of noise are you hearing?
>
> 73, Roger
>
> --
> Remember the USS Liberty (AGTR-5)
> http://ussliberty.org/
>
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