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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