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Re: LF: SpecLab helps plane hunt

from [wolf_dl4yhf] [Permanent Link][Original]
To: [email protected]
Subject: Re: LF: SpecLab helps plane hunt
From: wolf_dl4yhf <[email protected]>
Date: Mon, 07 Apr 2014 17:44:51 +0200
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Hi Pete, Mike, Alan, and all,
I was also sceptic about the first "detection" (by the Malaysian or was it a Chinese search vessel).
But to me, the spectrograms taken by the US team aboard Ocean Shield is convincing.
The screenshot at ABC is a bit blurred but one can nicely see the "bipp-bipp-bipp-..." periodic ultrasonic bursts (aka "pings"), just as they should look like: 

http://www.abc.net.au/news/2014-04-07/ocean-shield-detects-possible-mh370-black-box-signal/5372616
It's not just a wobbly carrier that comes and goes. In slow-CW-terms, it would be an "outstanding signal". The signal is picked up by a towfish pulled on a long cable, to get away from the QRM (vessel) as far as possible.
Now keeping fingers crossed that the batteries last a bit longer than specified. The experts say the pinger's battery usually degrades slowly, instead of "going QRT" abruptly. 

73,
   Wolf  DL4YHF .


Am 07.04.2014 16:16, schrieb M0FMT:

  Hi all
If their kit is that shaky do 
  they understand that EM "breakthrough" into the
  long trailing  antenna like cables from the sensors at 37.5
  kHz is possible?  i.e. Powerful VLF TX operating in that
  frequency range because of its sea penetrating properties
  for very purpose of communicating with submerged Naval
  Submarines. Or is the acoustic PING encoded to avoid this
  confusion?
73 es GL Pete 
  M0FMT IO91UX
-------------------------------------------- 
  On Mon, 7/4/14, Mike Dennison <[email protected]>
  wrote:
Subject: LF: SpecLab helps 
  plane hunt
   To: [email protected],
  [email protected]
   Date: Monday, 7 April, 2014, 14:15
I have been amazed at the 
  low tech
   methods apparently being used in
the hunt for the 'pings' from the 
  black box of the missing
   Malaysian
   plane.
But 
  today the BBC lunchtime news showed the Ocean Shield
   search ship
   using
  DL4YHF's Spectrum Laboratory, presumably with a 96kHz
   soundcard
   as its input -
  exactly the kit used for the recent amateur
radio 
   transatlantic tests on 29kHz.
Well done, Wolf. Your 
  excellent software may help solve this
mystery. de Mike, 
  G3XDV
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