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Date: Mon, 07 Apr 2014 17:44:51 +0200
From: wolf_dl4yhf <dl4yhf@freenet.de>
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Subject: Re: LF: SpecLab helps plane hunt
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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 <mike.dennison@ntlworld.com>
>   wrote:
>   
>    Subject: LF: SpecLab helps
>   plane hunt
>    To: rsgb_lf_group@blacksheep.org,
>   rsgb_lf_group@yahoogroups.co.uk
>    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
>    
>
>
>
>