[UK-CONTEST] Data contests

[geoff plucknett]

Also agree with the general sentiment.

And to add to an earlier thread, turn off your speech compressors. Some of
those PSK signals on Thursday looked like a 6 lane motorway!

Geoff G4FKA

On 22 January 2011 10:36, David G3YYD <g3yyd at btinternet.com> wrote:

> I agree, it is always up to the receiving station to ask for a repeat if
> there is any doubt about the received exchange being correct. Repeating
> the exchange back wastes time at the best and at the worst adds confusion.
>
> N1MM software by deliberate design does not have a macro to allow the
> received exchange to be repeated back.
>
> Same with RYs all that is needed is a space character before the first
> printable character is sent. This separates the wanted text from the
> previous garbage characters. Same goes for CRLF please do not do that as
> it means having to chase data as it scrolls up the screen. A space at
> the beginning  and at the end of a callsign helps callsign
> identification software to work and automatically grab the call cutting
> down operator fatigue. The same goes for the exchange bracketing each
> part of the exchange with space helps the software grab the correct data
> when clicked upon.
>
> Also turn on UoS - Unshift on Space - for TX and RX this helps copy when
> figs/ltrs shifts become corrupted saving a repeat being asked for.
>
> Also set the software to work with TX stop bit of 1.5 and RX of 1. This
> is selectable in MMTTY configuration menu. This setting gives more time
> for the RX to resynchronise if a corruption has caused the RX to respond
> to a false start bit.
>
> On the sound card settings do not use 11025Hz sampling rate as modern
> sound cards will not provide an accurate rate. It is better to use
> 12000Hz. Modern sound card sample at 48KHz or integer multiples of
> 48KHz. The driver software then converts the 48KHz to the requested
> speed. As a result 12KHz is easy to do by sending every 4th sample to
> the decoding software. Generating 11025 from such a card will result in
> a compromise rate, which could be significantly different. This does
> result in TX/RX baud rate being incorrect along with the received tone.
> If using FSK this can mean you call people off frequency another reason
> for using AFSK rather than FSK.
>
> The baud rate setting should be 45.45 and not 45.
>
> 73 David G3YYD
>
> On 21/01/2011 20:11, Colin Chidgey wrote:
> > I'm with Robin G3TKF on this one.
> > Its plainly daft to send my report to you back to me!
> > In poor conditions with broken reception I am likely to take
> > a guess at the numbers coming back and the last number I need is
> > mine repeated to me.
> > Strings of RYRY are also silly.The RY sequence was used with mechanical
> > teletype machines to exercise the cogs! My DSP/FFT software does not use
> > cogs (I think).
> > Colin G3YHV
> >
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