RE: [HCDX]: Noisetrouble

["Rauhala Jyri (NMP)" <Jyri.Rauhala@xxxxxxxxxxxxx>]

Afew years back I had VERY similar problems, everything was blanketed
completely from LW up to around 6 MHz.

After long studies (you'd better do this at night, otherwise your
neighbours will thing you are out of your mind... on the other hand, IF
they see you THEN, they will definitely think that...) of walking around
with a portable radio and headphones as well as momentarily switching
off the electricity from the entire house of mine (not that easily done
if you are living in an apartment building) I found out that the source
of noise was somewhere NOT in my house but within 100-200 m from it. AND
it seemed that after all the noise was coming through the electricity
wiring and then jumping to the antenna (so it wasn't entering my radio,
Lowe HF225 through the AC adapter but through the antenna...)

OK, then I had to start talking to the neighbours...
The first mains switch: no effect
The second mains switch: complete silence in my headphones.
I never bothered to try the third, fourth, fifth, sixth and seventh
potential one...

After some further studies we found out that the reason for the
interference was my neigbour's set of christmas lights he had hanging
around the bushes in the garden. He had bought a VERY nice looking set
in the US (110 Volts) and the nice guy in the shop had then given him a
nice downconverter (very lightweight, the size of a typical AC adapter)
so that he can use them here in Europe (230V).
Apparently the converter was made with a thyristor brutally slicing the
AC voltage to effectively create something that the lamps would regard
as 110V. Unfortunately the VERY UNBRANDED gadget seemed to have no
filtering, so it acted like a good noise supply polluting the wiring in
the neighborhood.
My neighbour is a nice guy, he took the gadget away and promised never
to use it again.

If you cannot find the source of noise together with your neigbours then
you can call your electricity company. It is their responsibility to
supply you with clean electricity and at least here in Tampere, Finland
there was a very friendly guy (there was quite some trouble finding him,
it took me several phone calls to different people in the electricity
company before someone could guide me to the right people) who had
apparently been doing a lot of measurements, mainly in order to find
faulty wiring and transducers causing interference to people's TV's.
The thing with the electricity company is that once they bring in their
measurement equipment it starts costing money. If it is in their system
they'll pay of course, but if it is something a neighbour has bought...

Good hunting,
Jyri



> -----Original Message-----
> From:	EXT jm [SMTP:jm@xxxxxxxxxxxxxxxx]
> Sent:	11. elokuuta 1998 21:58
> To:	hard-core-dx@xxxxxxxxxxxxx
> Subject:	[HCDX]: Noisetrouble
> 
> At very irregular times I suffer from a very hard buzzernoise going
> from
> MW till 7000 KHz.  The signal of this noise is at its strongest
> between
> 2400 KHz and 2500 KHz with peaks up to Signal 9+15 db.
> I tried to cut off all electric devices in my house but the noise just
> continued.
> It also doesn't come via the electricity way because when I unplug my
> antenna, the noise is completely gone.
> I also went out with a portable (Panasonic RF-B65) to try and localyse
> the source of this buzzing noise but all attempts without result.
> The noise appears in the late afternoon and mostly stays on for the
> rest
> of the night.  I have never noticed it around noon.
> I use a Kenwood R5000 and R2000 (never sold my first rx) and a
> longwire
> in sloper with balun.
> Can someone help me to reduce this annoying noise.
> All advice is very wellcome.
> tnx in advance.
> Johan
> 
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This is a message from "Rauhala Jyri (NMP)" <Jyri.Rauhala@xxxxxxxxxxxxx>
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For more information, please check http://www.iki.fi/rko/hard-core-dx/
or email Risto Kotalampi, risto@xxxxxxxxxxxxxx
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