HI Bill,
you do not want to reinvent "THE QUICK BROWN FOX JUMPS OVER THE
LAZY DOGS BACK", do you? ;-)
73 de Goetz
dj3iw@t-online.de
----- Original Message -----
From: "Bill Turner" <wrt@dslextreme.com>
To: "Kok Chen" <chen@mac.com>
Cc: "RTTY Reflector" <rtty@contesting.com>
Sent: Wednesday, April 21, 2004 4:44 AM
Subject: Re: [RTTY] A repository of (poor) RTTY recordings?
> On Tue, 20 Apr 2004 13:53:25 -0700, Kok Chen wrote:
>
> >It is perhaps useful for the RTTY community to have available a
> >"standard" collection of digitized sound files of various RTTY signals.
> > Not the clean loud stuff that we already have on the web as examples
> >of FSK, but some watery fluttery hard to copy, etc. stuff.
> >
> >All of us could then use the same digitized sound files to play back
> >into whatever system we are testing so there would be some consistency.
>
> _________________________________________________________
>
> Would it be a good idea to come up with a standard text message we could
> all use for this? I'm thinking if we knew in advance exactly what was
> sent it would make it possible to count the errors on a particular
> transmission and thereby have some hard numbers to compare various
> filter and demodulator settings. If we had numerous examples of the
> same text, sent under many different propagation conditions, we could
> run them through our different programs and TNC's and begin to come up
> with some meaningful statistics.
>
> As a first stab at it how about:
>
> RYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRY
> RYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRY
> RYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRY
> RYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRYRY
>
> For a total of 200 characters, not including the carriage returns. This
> is visually easy to scan for errors and then just count them. For a
> given file, one might get five errors with one setting, four errors with
> a different setting, zero with a different one and so on. You could
> then use a different file with different amounts of flutter and
> multipath and repeat the experiment. Then yet a different file, and so
> on.
>
> As an alternative, perhaps blocks of text might be easier to count:
>
> RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY
> RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY
> RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY
> RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY
> RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY
> RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY
> RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY
> RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY
> RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY
> RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY RYRY
>
> For a total of 100 blocks. Then just count the correctly received
> blocks and that would be the score. 100 = perfect.
>
> These are just my first couple of thoughts on the subject. There are
> probably other text groups that would be easier to score.
>
> Comments?
>
> --
> Bill, W6WRT
> QSLs via LoTW
>
> _______________________________________________
> RTTY mailing list
> RTTY@contesting.com
> http://lists.contesting.com/mailman/listinfo/rtty
>
_______________________________________________
RTTY mailing list
RTTY@contesting.com
http://lists.contesting.com/mailman/listinfo/rtty
|