Envelope-to: dave@picks.force9.co.uk
Delivery-date: Fri, 02 Dec 2005 17:26:28 +0000
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From: "Laurence KL1X" <hellozerohellozero@hotmail.com>
To: rsgb_lf_group@blacksheep.org
Date: Fri, 02 Dec 2005 08:25:41 -0900
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Subject: Re: LF: loran c closure
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"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"

You can say that again - I can tell you the phase distortion and dalek 
effect is very noticeable in Aberdeen and makes the signal very difficult to 
listen too - luckliy they do a rebro on MW. More luckily I dont live in 
Aberdeen any more

Laurence GM4DMA as was


>From: "Alan Melia" <alan.melia@btinternet.com>
>Reply-To: rsgb_lf_group@blacksheep.org
>To: <rsgb_lf_group@blacksheep.org>
>Subject: Re: LF: loran c closure
>Date: Fri, 2 Dec 2005 16:39:06 -0000
>
>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
> >
> >
> >
> >
>
>