Subj : Da Di Dit  Dit - Rulz
To   : ROY WITT
From : STAN PHILLIPS
Date : Tue Aug 29 2000 08:12 am

RW> MSGID: 1:10/22 39a8d523
RW> REPLY: 2:252/171 fc9336dc
RW> PID: GEDW32 3.0.1
RW> CHRS: IBMPC 2
RW> TID: FastEcho 1.46.1 8614
RW> Hello STAN.
RW> 
RW> 24 Aug 00 21:50, you wrote to me:
RW> 
RW>  RW>> Since marine and aircraft no longer use CW, there's no need for CW
RW>  RW>> beacons. I think you'll find that they're all using digital
RW>  RW>> communications now.  I think it was France who announced back in
RW>  RW>> 1998 that the end of that year (or the following February) signaled
RW>  RW>> the end of their CW in their maritime service. I believe the
RW>  RW>> announcement said that they were the last country to do so.
RW> 
RW>  SP> Perhaps there is no need, however they are there and are still being
RW>  SP> used. They may indeed give a digital signal however I have no info on
RW>  SP> that, other than the operating frequency is rather low (below 500
RW>  SP> Khz) and I would have expected a digital to be heard as well as the
RW>  SP> code identification is.
RW> 
RW> A digital ID is in ASCII code 

Then the code ID is just that, code.

I have just taken a look at my 'aeronautical map' for this area (VFR
Terminal area chart) and the beacons giving code ID are all there. I
have just taken a listen on the rig and the local ones are still transmitting.
The signal is constant unmodulated RF with an AF tone modulation (MCW)
giving the ID in code at regular intervals.  The code ID on the maps
is given as 'dots and dashes' and is transmitted quite slowly so
those using the maps can easily identify them. The ID in in the form
of 2 or more characters.

The frequecies are all below 300 KHZ so that echoes do not give wrong
DF readings. 

RW>  RW>  SP>> The satelites I am referring to include the commercial
RW>  RW>  SP>> television satellites. Each transponder has it's own
RW>  RW>  SP>> identification in code.
RW>  RW>>
RW>  RW>> In a digital format.
RW> 
RW>  SP> Well,  I suppose that normal morse code could be classed as
RW>  SP> 'digital'.
RW> 
RW> Not unless it's dual tone.

Then it is normal MCW code.

RW>  SP> They are not using radios. They are using normal AF though a
RW>  SP> loudspeaker.
RW> 
RW>  SP> Some are now using code to ascii converters as input to a normal
RW>  SP> computer.
RW> 
RW> Then there's no longer a need for the loudspeaker, just a set of
RW> headphones for those who can't type.


Take a look at this web page. It gives info on one of the paralyzed
people using code to communicate.  This is only one of many.

http://www.healthweek.com/features/ahfeat4.html

Just out of interest, if you know anyone that has a C band TV
satellite system, pick any transponder (channel), go to the sound
setup.  If it is digital sound, change it to normal and tune to above
the normal upper limit of 6.8 Meg to just above 7 meg. You will hear
the morse code "transponder and user ID". In MCW.  Unlike the
navigtional beacons, the code is about the 18-20 WPM speed.

73  Stan


 * Being "nice" doesn't cost, but it often pays.
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