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VK5QX > CW 01.08.05 08:48l 56 Lines 1729 Bytes #999 (0) @ WW
BID : 9F0996VK5QX
Read: GUEST DF1GG
Subj: Re: Aldis lamps..
Path: DB0FHN<DB0CL<DB0PDF<DB0SM<DB0EA<DB0RES<ON0AR<IW8PGT<CX2SA<VK4TRS<
VK4DGQ<VK4WIE<VK2JSM<VK2PYU<VK2TV<VK5ZAR<VK5SPG<VK5LZ
Sent: 050725/0508Z @:VK5LZ.#ADL.#SA.AUS.OC #:47351 [Elizabeth] $:9F0996VK5QX
From: VK5QX@VK5LZ.#ADL.#SA.AUS.OC
To : CW@WW
SECURITY!
Mel G4WYW posted a very interesting bulletin describing, in some detail,
the makeup and functions of an "Aldis lamp".
I can remember that, as a lad, back during WW2 I was quite fascinated by
the usage of such a device.
One particular aspect that Mel did not mention was the benefit that these
signalling devices gave from the security point of view.
He did say, in part;
__________
" A highly polished silver concave mirror behind the bulb, concentrates
the
light to a narrow but highly intense beam of light that penetrates and can
be seen even in bright daylight... "
__________
As the light beam was so tightly concentrated and indeed very narrow, it
was usually possible, by correctly aiming the beam, to send a message to
another vessel without others, particularly an enemy vessel, intercepting
the message.
This of course would not apply IF the enemy was in the same line of sight
as the intended recipient, however, judicious use of such a system could
certainly result in messages being sent with a very good chance of
remaining secure.
A lamp type signalling system of such a nature obviously would only
(normally) be used for relatively short distance communication. Such use
also enhances security capability.
Messages can be sent on an immediate basis without a need for coding,
although such could be incorporated if thought necessary, despite the fact
that a little extra time for coding/decoding would apply.
Even with the use of very short radio messages one could not be sure of
providing security to the same degree as provided with the famous Aldis
Lamp.
Regards,
Ian
__________
73 de Ian, VK5QX
@ VK5LZ.#ADL.#SA.AUS.OC
25 July 2005
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