[CW] Human decoding of weak CW sigs in noise

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I made high precision Morse sound files with each 4 groups of 5 random 
chosen characters.

The code is embedded in flat white noise with a bandwidth of
300-2800 Hz. tone pitch 712 Hz, speed 12 wpm

the S/N ratio is MINUS (10, 11, 12 and 13) dB

Also there are 4 files with use of a CW filter 150 Hz wide.

When you play the files it is important to experiment with the audio 
level for best decoding.
You may replay the files, the noise is exactly the same so that is not 
considered  cheating.

Please sent your copy to my mail address tuv at xs4all.nl

Results will be published here, unless you write me that you don't want 
that.

First file (-10dB 2.5 kHz bandwidth) can be found on

http://pa0wv.home.xs4all.nl/eham/a.wav

next files by changing in the URL a.wav by b.wav and so on till h.wav 
for number eight.

tks es 55
Wim PA0WV