[RTTY] A repository of (poor) RTTY recordings?

[DJ3IW Goetz]

HI Bill,

you do not want to reinvent "THE QUICK BROWN FOX JUMPS OVER THE
LAZY DOGS BACK", do you? ;-)

73 de Goetz
dj3iw at t-online.de
----- Original Message ----- 
From: "Bill Turner" <wrt at dslextreme.com>
To: "Kok Chen" <chen at mac.com>
Cc: "RTTY Reflector" <rtty at 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
> 
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