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PSK-31 Reality Check



Wow.  Here is a great Demo of Acoustical Phase shift!

I had PSK-31 running in diddle mode through the PC speaker so I could
capture the waveform for students on a Scope across the room.  As you
know this sounds like a pure tone with pure warble...

But each time I went to move over to the O'Scope to look at it, it sounded
like the PC started to send text!  But I went back to the PC, and it was
pure diddile.  I tried this several times, and each time I moved, I swear,
it sounded like someone began sending text.

Bingo!  The accoustic phase shifts by reflection from objects in the room
as I walked was introducing  phase shifts which sound identical to the
random phase shifts that occur in random text.

I'm sure someone walking by thought I was nuts as I walked about the room
shaking my head...  I can imagine now that with a pure diddle from a
speaker and a microphone on a moving platform, one could build a
mechanical maze that could actually spell something!

The biggest problem was the big echo reverberation between my ears
(grin)...

Anyway, it was an interesting observation that anyone can do...

Bob, WB4APR




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