Hi John,
Sorry to hear of your noise problem. Don't give up, despite the
effect it's having on your reception right now. I had a similar problem up
to quite recently, as you know, but I was lucky that it more or less solved
itself. However, I had put in train an investigation by a unit in our
National Broadcasting organisation , Radio Telefis Eireann, RTE, who check
out interference to their broadcasts, since there was an element of that in
my case. Seems like you have some of that too. As it happened, before they
were to come on site to check, a power line near our house was removed and
connected to another circuit, when the Office of Public Works undertood a
complete restoration of a national monument, just across the field from our
house. The Celtic cross, dating from the 6th century, is one of the earliest
examples of worked stone, producing a simple cross, and is engraved with
patterns and figures. It has been moved slightly to a purpose built site
and is now roofed over to provide protection. Just as well, for it and for
me, since the re-routing of the power line restored my sanity.
During my qrn/qrm war, I could be seen with my HF225 rx, prowling about
trying to get the source, without effect. When I got set up in the car and
drove about, everywhere but my location seemed to be free of noise. This
lasted for over 4 months and nearly drove me mad. I kept switching off my
radio gear in disgust and then would slink back and switch on again in the
vain hope it had somehow gone away. When it did , finally go, I did not
trust the situation, still don't, and half expect it to come back at any
time. At one time I considered having an rx at a remote site and feeding
back the audio, but the sheer effort of finding a site etc etc put me off
that idea.
If it really does carry on, I feet the radio investigation branch
approach would be your best bet. I had a lot of help and advise from many
of the LF gang, and it really helped me keep going.....thanks to all for the
help.
Don't give up , John, we want you back on the band.
73'
Finbar EI0CF
-----Original Message-----
From: Kate Moore <[email protected]>
To: lfgroup <[email protected]>
Date: 03 June 1999 09:07
Subject: LF: Noise problems
I guess it had to happen eventually; after months of generally low-noise RX
on LF, I have suddenly got a serious local QRN problem. It started abruptly
at the beginning of last week and has been on continuously since then. The
'850 s-meter reads a steady S9 on 136kHz, with a continuous roaring in the
speaker (like a cross between motor spikes and wider pulses), so I am
struggling with even the loudest LF signals, let alone weak DX. It extends
below LF and up past 7MHz, so even 40m work is difficult.
We first noticed it on the BC RX in the kitchen, when listening to a
medium
wave station from Coventry (which we are JUST outside the coverage area of)
which was noisey, as if their TX was running low power - not so. Local and
national LW/MW signals intended for this area aren't noticably affected. I
went out with a Walkman on Monday trying to DF it and it is easily
detectable
beyond the block our house is on - peaking about 200m behind our house,
over
a busy main road. I couldn't get an accurate fix on it due to local phone
lines and buildings giving false nulls, and whilst I was wandering back and
forth, a local dog-walker challenged me as to what I was up to and clearly
didn't accept my explanation, so I gave up!
It's difficult to decide what is causing the noise - the area is very
mixed
large domestic plots with some shops and tiny industrial units, but mostly
housing. From the physical and frequency range it is detectable over, it
must
be causing BC problems to houses closer than we are, but I imagine most
people wouldn't understand what was happening. It is on continuously and
must
either be a large 'dirty' installation, something very seriously breaking
down or possibly one of the new broad-band signalling systems (although I
doubt the latter).
Whatever it is, whilst it's on, I'm effectively QRT on 136, topband, 80m
and 40m; so I need to get to the bottom of it. From what I've said, does
anyone know whether the authorities would be sympathetic to tracking it
down and getting the owner to clean it up, or am I on my own? Has anyone
had any success in similar circumstances? I think Derek had trouble with a
noise source last year - did you get it cleaned up, Derek, or did you have
to work around it? All hints and suggestions gratefully received.......
John G4GVC near Leicester, IO92JP
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