Message-ID: <001a01c86d95$ce1f6da0$0300000a@AGB>
From: "Graham" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <001e01c86bd7$38723a90$0301a8c0@ken> <000701c86bed$4f9a69c0$0900a8c0@Lark> <0f9b01c86bf5$dda5a880$0300000a@AGB> <fc7eccec0802110007t420a05dds20aff3877bb83bfe@mail.gmail.com> <001801c86c9f$31f97110$6d01a8c0@JAYDELL>
Date: Tue, 12 Feb 2008 16:39:05 -0000
MIME-Version: 1.0
Subject: Re: LF: Windows Beacon TX/RX Software .. can anyone code such a thing ?
Content-Type: text/plain;
	format=flowed;
	charset="iso-8859-1";
	reply-type=response
Content-Transfer-Encoding: quoted-printable
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org


Thank you for that Jay,

The idea is to  have a system thats quite relaxed , with wide guard bands to=
=20
allow for
system 'cycle time' and clock errors , so anone can join in with a pc ,=20
sync'd to  the
internet or a time signal

G..




----- Original Message -----=20
From: <jrusgrove@comcast.net>
To: <rsgb_lf_group@blacksheep.org>
Sent: Monday, February 11, 2008 11:13 AM
Subject: Re: LF: Windows Beacon TX/RX Software .. can anyone code such a=20
thing ?


> Been using Dimension4 for several years now on a number of different=20
> computers. You can pick any time server and choose the synchronization=20
> down to seconds - if necessary. Not sure if this is accurate enough for=20
> your work but it might be worth a look.
>
> http://www.thinkman.com/dimension4/index.htm
>
> Jay W1VD  WD2XNS  WE2XGR/2
>
>
> ----- Original Message -----=20
> From: Andy Talbot
> To: rsgb_lf_group@blacksheep.org
> Sent: Monday, February 11, 2008 3:07 AM
> Subject: Re: LF: Windows Beacon TX/RX Software .. can anyone code such a=20
> thing ?
>
>
> A problem with the scheme you suggest, Graham, is that PC clocks maintain=20
> time badly, and will drift by several seconds overnight which makes a=20
> mockery of the idea of precisely timed sequential listening.  They may be=20
> able to acheive Internet synchronisation, but can this be set up to=20
> automatically update at the rate you will need, ie. every hour or two=20
> based on some of the clock drifts I have seen.
>
> That is why the existing beacon chains, both 5MHz and the IBP set, use GPS=
=20
> timing.  Passive receiving stations have their timekeeping reset by the=20
> actual 5MHz transmissions themselves.  On your website, you do mention MSF=
=20
> timing, but to do that in real time would consume another receiver /=20
> soundcard channel.    GPS is the only obvious way to go for transmitting=20
> stations.   PCs are not reknowned for their timekeeping abilities!
>
> Otherwise, the software is straightforward, although rather a waste of a=20
> PC. If the GPS is available, then a =A31 PIC is all you need to control an=
d=20
> key a standalone transmitter that doesn't need soundcard drive.
>
> Andy  G4JNT
> www.scrbg.org/g4jnt
>
>
> On 10/02/2008, Graham <g8fzk@g8fzk.fsnet.co.uk> wrote:
> Hi all,
>
>
>
> This is something that may be of interest  .. To a programmer or two or
> three ? There exists collectively the expertise, but can anyone see a way=20
> of
> producing the system?
>
>
> The idea  came initially from the 'Beacon Bedlam' , that existed south of
> Watford gap .. about the only time the skip distance on 500 was 'useful'=20
> in
> that band conditions in the north west where quite quiet, later to  prove=20
> a
> hindrance,
>
>
>
> There already exists a similar system on 5 Mhz , however the transmission
> sites are defined and  participation is only possible by 'passive=20
> reception'
> not too appealing for 'experimentation' This is a 'proposal' the concept=20
> is
> proven , but 'we' need the
> services of a programmer or two !! Similar thing's exist but are coded to
> use 'pics' ,
>
>
>
> One of the main criteria is , that 'anyone' with a windows based pc should
> be able to download and install the tx/rx  software and join in, be it as=20
> a
> TX station, simply claim a 'time slot' ,  or a passive observer being
> presented with all 5 slots as a amplitude/time plot.
>
>
>
> One of the  main attractions would be : TX stations will be able to=20
> observe
> the other beacons in the chain , eliminating the lonely vigil of being in
> perm ante
>
> transmit mode, while providing , at a glance, band conditions  for all
> involved as well as reducing tx duty cycle time !
>
>
>
> The number of TX stations is proposed as 5 in the chain , more may be
> possible , but the time control factor may prove too difficult to achieve
> within windows , but cw type software in beacon mode would appear top=20
> make
> a reasonable job of time control ?
>
> Click on=20
> http://groups.google.com/group/uk500khz/web/the-big-beacon-project
> - or copy & paste it into your browser's address bar if that doesn't
> work.
>
>
>
>
>
>
>
>
>
> --=20
>
>
>
>
>
> --=20
> No virus found in this incoming message.
> Checked by AVG Free Edition. Version: 7.5.516 / Virus Database:=20
> 269.20.2/1271 - Release Date: 2/11/2008 08:16
>
>=20