Envelope-to: dave@picks.force9.co.uk
Delivery-date: Fri, 02 Dec 2005 17:26:49 +0000
Message-ID: <003501c5f765$39f5ba10$2201a8c0@AUG2004>
From: "Walter Blanchard" <blanch@pncl.co.uk>
To: rsgb_lf_group@blacksheep.org
References: <003001c5f759$05b2c880$f500a8c0@Dell5150> <000601c5f75f$b4d15a60$44187ad5@lark>
Date: Fri, 2 Dec 2005 17:24:14 -0000
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Subject: LF: BBCR4
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Dave,
Last year I mentioned the LW R4 chaos in Scotland to a "senior BBC engineer" 
(in quotes because he won't let me give his name).
He just laughed and said you won't get anyone in the Beeb to take any 
interest in it these days - they've all gone to DAB and suchlike.
They look on LW/MW as obsolete "rubbish" bands, sooner they're phased out 
the better, but of course won't say so publicly.
Like many radio engineers these days they look on anything below 100 MHz as 
history. Shouldn't we put in a claim for one gigantic
ham band stretching from DC to 100 MHz????? I'll bet the UWB people would 
support us.
Walter G3JKV.


----- Original Message ----- 
From: "Alan Melia" <alan.melia@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
Sent: Friday, December 02, 2005 4:39 PM
Subject: Re: LF: loran c closure


> Hi Dave I dont think its the phase mod that is creating the "Dalek 
> effect".
> I think this is more likely to be interference between the two signals.
> Westerglen is not "controlled" (should be "measured" really) by NPL though
> it does have a rubidium source. Could the Dalek effect be due to the time
> delay in the program modulation reaching Scotland there must be up to 
> about
> a millisec. That means there is only very slow fading as the carrier phase
> difference is fairly constant but the mod is out of phase and beating. I
> know the wide area quasi sync PMR systems beloved of Pye-Philips (and
> laterly Simoco) used to have audio delay lines for equalising the delay
> between sites, as well as ovened crystal reference standards (the old
> HS400).
>
> Cheers de Alan G3NYK
>
>
> ----- Original Message -----
> From: Dave Pick <dave@picks.force9.co.uk>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: 02 December 2005 15:56
> Subject: RE: LF: loran c closure
>
>
>> That phase modulated data is a real pain. In the Scottish borders
> Droitwich
>> beats with Westerglen (between Glasgow and Edinburgh) which either 
>> doesn't
>> have phase mod data, or has different data on it. The net result sounds 
>> as
>> if the Daleks have taken over radio 4. Surely there are better ways of
>> signalling to electricity meters or whatever it's for?
>>
>> Dave G3YXM.
>>
>> -----Original Message-----
>> From: owner-rsgb_lf_group@blacksheep.org
>> [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Johan Bodin
>> Sent: 02 December 2005 11:14
>> To: rsgb_lf_group@blacksheep.org
>> Subject: Re: LF: loran c closure
>>
>> Warren,
>>
>> >   BBC 4 from Droitwich on 198 kHz  is kept in very close tolerance by
> the
>> NPL.
>> > http://www.npl.co.uk/time/droitwich_bulletin.html
>>
>> Yes, but it is not so easy to use "right out of the box" because it has a
>> lot of phase jitter (intentional PSK) that has to be smoothed out.
>>
>> 73
>> Johan SM6LKM
>>
>>
>> --
>> No virus found in this outgoing message.
>> Checked by AVG Free Edition.
>> Version: 7.1.362 / Virus Database: 267.13.8/184 - Release Date: 
>> 2005-11-27
>>
>>
>>
>>
>