Re: LF: SpecLab helps plane hunt

["iz7slz.domenico" <iz7slz.domenico@gmail.com>]

Hello all,

Also Voyage Data Recorders (VDR), i.e. the black-box for the vessel, is equipped with an acoustic beacon.

See picture of one VDR "capsule" (protected memory)

https://www.dropbox.com/s/22jk0ht3xx9soag/20131128_145029.jpg

The small cilindred is the beacon.

It is able to send a beep in the range 25 - 50 kHz for a period of minimun 30 days when ship sinks.

During mandatory annual surveys , beacon need to be tested. I use one small "pinger" instrument and Spectrum Lab to do these checks.

Once again thanks Wolf!

73, Domenico iz7slz

Sent from Samsung Mobile

-------- Original message --------
From: Graham

Date:07/04/2014 7:02 PM (GMT+01:00)
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: SpecLab helps plane hunt

Or is the acoustic PING encoded



The  recovery sonic beacons  send only  a  pulse    

flight  boxes are not the  only  things  that  have
locator  beacons , other  'things'  that  occasionally
are lost by accident  or design  also  have  ping'ers
that  work  round this  frequency ,  the  surfacing
radio  boys  have encoding etc 

lower  freq  would  travel  better  , but  be  more  vague
as to  location of the  source , no  one has mentioned the
Sub (s ?) for a  while ?

G,



--------------------------------------------------
From: "M0FMT" <m0fmt@yahoo.co.uk>
Sent: Monday, April 07, 2014 3:16 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: Re: LF: SpecLab helps plane hunt

> 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
>  
>
>