Re: LF: Windows Beacon TX/RX Software .. can anyone code such a thing ?

["Andy Talbot" <andy.g4jnt@googlemail.com>]

A problem with the scheme you suggest, Graham, is that PC clocks maintain time badly, and will drift by several seconds overnight which makes a mockery of the idea of precisely timed sequential listening.  They may be able to acheive Internet synchronisation, but can this be set up to automatically update at the rate you will need, ie. every hour or two 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 timing.  Passive receiving stations have their timekeeping reset by the actual 5MHz transmissions themselves.  On your website, you do mention MSF timing, but to do that in real time would consume another receiver / soundcard channel.    GPS is the only obvious way to go for transmitting stations.   PCs are not reknowned for their timekeeping abilities!

 

Otherwise, the software is straightforward, although rather a waste of a PC.   If the GPS is available, then a £1 PIC is all you need to control and 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 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' in
that band conditions in the north west where quite quiet, later to  prove a
hindrance,



There already exists a similar system on 5 Mhz , however the transmission
sites are defined and  participation is only possible by 'passive reception'
not too appealing for 'experimentation' This is a 'proposal' the concept 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 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  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  make
a reasonable job of time control ?

Click on 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.

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