Its difficult Stefan because everyone is different, I didnt get much trouble
from DCF39 when I got a radio with a decent (Collins) IF filter. In some
part of the world its cleaner since the demise of Loran-C but some places it
is much worse because CFH and the other station at the mottom of the band
started using faster baudrates and GMSK.
My local interference level here was up around 10dB due to SMPS and TVs and
the occasional PC, about 4 years ago. I have not listened actively since
then, I can no longer get a clear run between my mast at the house and my
remote pole so have not had the same antenna up. (Time to get the chainsaw
out :-)) ) It is self inflicted, some Eucalypus trees planted as seeds in
the early 1970s are now 60 feet high!! :-(( it does a world of good for my
carbon footprint though . The trunks are about 40cms diameter so there is a
few tonnes of wood there!!
Some reported a big drop in the noise level on 136 when The Lessay chain
went off-air for maintenance. The Rugby experiment with eLoran made
conditions unworkable in the midlands of the UK until it was moved to
Anthorn. This effectively drove Dave Pick G3YXM off the band.
In general the UK noise "profile" was always accepted to be below the
standard lines in the ITU recommendations. The main reason being that we had
a very active Interference (Engineering) Department attached to the
"regulator". This ceased about 5 years ago. I dont think UK level is below
the line any longer though!
Alan
G3NYK
----- Original Message -----
From: "Stefan Schäfer" <[email protected]>
To: <[email protected]>
Sent: Friday, April 20, 2012 7:52 PM
Subject: Re: LF: Re: 136 propagation a QRO secret ?
> Hi Alan,
>
> What do you estimate, what is the average global background noise level
> increase in dB due to the rising QRM generators (SMPS, plasma TV, energy
> saving lamps.....) since these early days?
>
> 73, Stefan/DK7FC
>
> Am 20.04.2012 19:20, schrieb Alan Melia:
> > Hi Graham you may not be aware that the only modes that were available
in
> > the early days when the 1st TAs were achieved was QRSS3. Robert Horne,
> > author of Spectrogram saw now use or reason for a slower
> > waterfall.....remember he is a biologist and this suite was written for
> > recording and analysing animal and marine mammal sounds. The results
were
> > obtained in a period or high geomagnetic activity just after the peak of
the
> > last Solar max (Geomag activity trails sun-spots by about a year) We
have
> > just had the quietest minimum for years and the level of activity is
> > relative to the last max still quite low.
> >
> > The modern digital modes are around 20dB more sensitive than QRSS3 this
> > accounts for the difference between 100s watts and less that 10 watts,
even
> > allowing for quieter conditions. I think this is what you usually call
> > "progress" :-))
> >
> > Alan
> > G3NYK
> >
> >
> > ----- Original Message -----
> > From: "Graham"<[email protected]>
> > To:<[email protected]>
> > Sent: Friday, April 20, 2012 11:32 AM
> > Subject: LF: 136 propagation a QRO secret ?
> >
> >
> > Have the high power operators on 136 been keeping the real
potential
> > of 136 propagation a secret ? writing you name in neon light is
one
> > thing , but behind the glow of the sign , previously un seen, the
data
> > recording Op beacon system is starting to reveal some interesting
> > features of this band.
> >
> > Results from the first 'plug and play' 'peoples' beacon, seem to
> > show , DX operation on 136 is not quite as difficult as was
perhaps
> > made out , from the first TA decode of OP8 , using a
> > Parasol-on-a-Stick , with a few hundred watts , to RA3AGC long wire
to
> > the trees , with similar power and PA0A 'small array' .. 2000 Kmtr +
> > decodes are showing up on a quite regular basis , may be more than
that
> > offered by 500 KHz ?
> >
> > VK 136 operators have expressed interest in setting up sked's to
> > make, what could be the first full call sign decode , to down
under,
> > but to date, it seems there are no transmit takers this side ,
> >
> > Technically, the processing gain of OP32 , is very close to the
> > estimated -40 dB path loss , EU-VK and should require 16 mins
of
> > carrier above the s/n threshold in 32 mins to decode ...
> >
> > Anyone tempted to make a sked ?
> >
> > G,,
> >
> > 24 hour usage from http://pskreporter.info/pskmapn.html
> >
> > Txmtr Rcvr Band Mode Distance Time (UTC)
> > 7L1RLL 7L1RLL 2200m OPERA 0 kms 09:54:58
> > PA3BHT PA3BHT 2200m OPERA 0 kms 09:53:41
> > PA0WMR PA0WMR 2200m OPERA 0 kms 09:45:35
> > JH1ARY JH1ARY 2200m OPERA 0 kms 09:43:42
> > UA0SNV-1 UA0SNV-1 2200m OPERA 0 kms 09:36:19
> > JP1ODJ JP1ODJ 2200m OPERA 0 kms 09:34:55
> > JF1PSS JF1PSS 2200m OPERA 0 kms 07:38:29
> > UA0SNV UA0SNV 2200m OPERA 0 kms 07:33:19
> > JH1INM JH1INM 2200m OPERA 0 kms 06:39:52
> > JA8SCD JA8SCD 2200m OPERA 0 kms 06:29:50
> > 7L1RLL JH1INM 2200m OPERA 76 kms 03:34:10
> > 7L1RLL JA8SCD 2200m OPERA 26 kms 03:34:10
> > 7L1RLL JP1ODJ 2200m OPERA 50 kms 03:34:09
> > JH1GVY JH1GVY 2200m OPERA 0 kms 03:03:32
> > JH1GVY JH1INM 2200m OPERA 99 kms 02:53:27
> > JH1GVY JA8SCD 2200m OPERA 18 kms 02:53:27
> > JH1GVY JP1ODJ 2200m OPERA 29 kms 02:53:26
> > JH1GVY JH1ARY 2200m OPERA 8 kms 02:53:26
> > JH1GVY 7L1RLL/1 2200m OPERA 35 kms 02:53:25
> > JF1PSS JF1PSS 2200m OPERA 0 kms 00:05:54
> > JH1GVV JH1GVV 2200m OPERA 0 kms 23:52:38
> > RN3AGC RN3AGC 2200m OPERA 0 kms 22:14:04
> > PA0A PA0A 2200m OPERA 0 kms 21:41:06
> > PA0A RW3ADB 2200m OPERA 2017 kms 21:39:21
> > PA0A RN3AGC 2200m OPERA 2020 kms 21:39:04
> > RW3ADB RW3ADB 2200m OPERA 0 kms 21:29:27
> > G0KYE G0KYE 2200m OPERA 0 kms 21:24:03
> > PA3ABK PA3ABK 2200m OPERA 0 kms 20:36:47
> > PA0OCD PA0OCD 2200m OPERA 0 kms 19:45:48
> > G8HUH G8HUH 2200m OPERA 0 kms 19:01:25
> > PA0OCD PA0A 2200m OPERA 128 kms 18:50:46
> > G4MDH G4MDH 2200m OPERA 0 kms 18:32:30
> > YO2LDK YO2LDK 2200m OPERA 0 kms 18:31:21
> > PA0OCD PA3ABK 2200m OPERA 62 kms 17:44:05
> > LZ1LZ LZ1LZ 2200m OPERA 0 kms 15:12:01
> >
> >
>
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