G8MNY  > TECH     15.12.25 08:15l 44 Lines 1573 Bytes #196 (0) @ WW
BID : 47274_GB7CIP
Subj: AF Standing Waves
Path: ED1ZAC<ED1ZAC<CX2SA<F3KT<F3KT<GB7CIP
Sent: 251215/0751Z @:GB7CIP.#32.GBR.EURO #:47274 [Caterham Surrey GBR]
From: G8MNY@GB7CIP.#32.GBR.EURO
To  : TECH@WW

By G8MNY                               (New Apr 17)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)

While laying around for a week in Hospital and a noisy night time drug pump
Alarm on the adjacent bed, I found myself playing sound games when I could
not sleep.

   ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
   ³               Bed               ³
   ³Bed±±±±         ±±        ±±±±Bed³
   ³                ±±               ³________
   ³                                   Corridor
   ³                                  ________
   ³  ±±            ±±           ±±  ³
   ³  ±± []         ±±           ±±  ³
   ³  Bed Alarm     Me          Bed  ³
   ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ

I was in the middle of a 6 bed ward. The alarm was a loud pure note (1.5kHz?)
and I found with my head on one side and moving just a few mm, I could get a
VERY deep nulls (60dB) in the tone from the reflections bouncing up & down the
room.

   |  _    _    _    _    _    _    _    _  |
   | / \  / \  / \  / \  / \  / \  / \  / \ |
   |/   \/   \/   \/   \/   \/   \/   \/   \|
   |       ³            ³                   |
 Wall    Alarm        Nulls               Wall

Then when the nurse approached from the corridor, I could detect this with the
standing wave reflections were being disturbed. This gave a loud multiple
Doppler ping sounds for each node the nurse went through.


All quiet interesting when you have nothing else to do in Hospital at night!


Why don't U send an interesting bul?

73 De John, G8MNY @ GB7CIP


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