My 2 - penn'orth is that from frequent observation [reception in moving
car ] R4 LW ceases very abruptly at Lyon.
-----Original Message-----
From: flo flo <[email protected]>
To: [email protected] <[email protected]>
Date: 12 August 2003 21:44
Subject: Re: LF: Re: Re: BBC R4 LW "Frequency Standard"
...and R4 is pretty weak here in Alaska too compared with its Eureopean
counterparts across the Marche/channel (often some 20-30 dBs stronger) -
Ive
only managed to listen to cricket test match special on a few occasions -
and the freq is shared in an NDB Canadian Beacon some 600 miles south too
which doesnt help.
R4 LW 198Khz in Aberdeen Scotland was appauling - and that why they had a
MW relay...AM phase and all that...
Given the Power differences in some of the European LW stations R4 is very
much weaker than I would have imagined here, but, there are more than one
variables that influence signals quality and strength. I presume the R4 LW
station doesnt "beam" or does it?
Given the "speed"/sheer of the particles in the ionosphere - and they would
have to be moving quite fast; might we not see some blurring of phase from
the two locked sources?
Beacon
...and the WD2XDW beacon will be on from 0001Z on around 137.773Khzish
until
advised. I might get the locked freq source sorted tonight. The matching
system is now under cover and no deterioation of aerial current has been
seen. Around 2.3 amps.
Laurence - rainy Anchorage
From: "Alan Melia" <[email protected]>
Reply-To: [email protected]
To: <[email protected]>
Subject: LF: Re: Re: BBC R4 LW "Frequency Standard"
Date: Tue, 12 Aug 2003 20:30:48 +0100
Hi Hugh, yes I supose it would have some effect. The advantage is that all
the transmitters are under "atomic" control so there is almost a
continuous
phase difference between their carriers. The "mush" area, I think, refers
mainly to the reception and demodulation of the AM program material. I
suppose within ground-wave range there is "beat" when the strengths from
Droitwich and say Westerglen are approximately the same ....the beat
frequency would not more than 0.00001Hz or about 1 cycle in 30 hours (I
hope
my thumbnail calcuation is right....but I sure someone will tell me if it
isn't). I dont expect that would give much problem but the path
differences
from the different tranmitters might give some interesting effects at
distance. The only person I know who does monitor R4 is Laurence in
Anchorage.
Cheers de Alan G3NYK
[email protected]
----- Original Message -----
From: "Hugh M0WYE" <[email protected]>
To: <[email protected]>
Sent: 12 August 2003 16:21
Subject: LF: Re: BBC R4 LW "Frequency Standard"
> Hi Alan, Group,
> Interesting article about BBC R4 LW.
>
> Does the fact that there are multiple transmitters on this frequency
have
> any bearing on those who might use the 198kHz signal as a propagation
> indicator outside of the UK ?
>
> Presumably the interference pattern ("mush area") extends way beyond
our
> shores, and someone monitoring, say in the 'States might receive a weak
> signal, not because there was no propagation, but because the two
> transmitters happened to be in cancellation.
>
> I assume the signals that we might use for reference, such as DCF39,
have
> only one source.
>
> 73
> Hugh M0WYE
>
> ----- Original Message -----
> From: "Alan Melia" <[email protected]>
> To: "LF-Group" <[email protected]>
> Sent: Tuesday, August 12, 2003 3:57 PM
> Subject: LF: BBC R4 LW "Frequency Standard"
>
>
> > Hi All, I have posted the latest DTI Time & Frequency Club Newsletter
to
> my
> > web site. It contains a short description of the frequency control of
the
> > BBC Radio 4 Longwave transmitters on 198kHz, together with details
of
the
> > phase modulation data service it also carries on the carrier. This
will
be
> > interesting information for those of you who, like me, may have a
198kHz
> > off-air standard in your workshop.
> >
> > Download of the 68kB pdf file is available from the link in the
contents
> > section on the index page.
> > http://www.alan.melia.btinternet.co.uk/
> >
> > Cheers de Alan G3NYK
> > [email protected]
> >
> >
> >
> >
>
>
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