A signal lamp (also called an Aldis lamp, named for its inventor Arthur C. W. Aldis) is a visual signaling device for optical communication (typically using Morse code) – essentially a focused lamp which can produce a pulse of light. This pulse is achieved by opening and closing shutters mounted in front of the lamp, either via a manually-operated pressure switch or, in later versions, automatically. The lamps were usually equipped with some form of optical sight, and were most commonly used on naval vessels and in airport control towers (using color signals for stop or clearance).
Aldis lamps were pioneered by the British Royal Navy in the late 19th century, and continue to be used through the present day on naval vessels. They provide handy, secure communications during periods of radio silence as well as other times and were particularly useful for convoys operating during the Battle of the Atlantic. There were several types. Some signal lamps were mounted on the mastheads of ships, some small hand-held versions were also used ('The Aldis lamp') and other more powerful ones were mounted on pedestals. These larger ones used a carbon arc lamp as their light source with a diameter of 20 inches (50 cm). These could be used to signal to the horizon, even in conditions of bright sunlight. Although it was originally thought that it was only possible to communicate by line-of-sight, in practice it was possible to illuminate cloud bases both during the night and day which allowed for communication beyond the horizon. A maximum transmission rate possible by using flashing lights is no more than 14 wpm.
They have a secondary function as simple spotlights.
The idea of flashing dots and dashes from a lantern was first put in to practice by Captain, later Vice Admiral, Philip Colomb in 1867. His original code, which the Navy used for seven years, was not identical with Morse, but Morse code was eventually adopted with the addition of several special signals. Flashing lights were the second generation of signaling in the Royal Navy, after the flag signals most famously used to spread Nelson's rallying-cry before the Battle of Trafalgar.
The Commonwealth Navies and NATO forces use signal lamps when radio communications need to be silent or electronic "spoofing" is likely. Also, given the prevalence of night vision equipment in today's armed forces, signaling at night is usually done with lights that operate in the infrared (IR) spectrum making them less likely to be detected. All modern forces have followed suit due to technological advances in digital communications.
The posted coordinates are relevant to the cache, however, the cache is not hidden here and there is no need to go here, unless you are going to locate JFNZ by CommanderB0rg.
The final coordinates bring you to a location of some relevance too. Read the sign at the entrance gate for a better understanding.
More information on the Aldis Lamp can be found here.
The cache is a micro container with log book only. There is no space for trackers or swag.
replace the cache carefully so that it is there for others to enjoy after you- thank you!
