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rans6andrew
1st Jul 2016, 21:47
I was wondering how fast signalers would be able to send morse using those big post mounted lamps with the "venetian blind" shutters on the front. They obviously wouldn't get anywhere close to the speeds a telegraph operator with a morse key would achieve. The inertia of the mechanism and the distance the handle moves would limit the speed.

When reading morse beeps by ear, it is easier if they are going quite quickly, over 10 or 12 words a minute, when you start to hear the "shape" of the "letters" rather than counting the dits and dahs. The better training systems keep the letters fast, 15-20 wpm rate, but increase the spaces between them to give a bit of thinking time (Farnsworth method).

Does anyone know if the same "shape" recognition applies to fast optical signalling? Do our eyes learn intermittent light patterns like our ears pick up musical patterns?

Are there any fast optical systems in use? I'm only interested in those which are read by eye.

Thanks,

G0ULI
1st Jul 2016, 22:09
12 wpm is standard for light signals. 20 wpm is possible. Being able to read morse by ear is very different from reading light signals though. I can receive by ear and write a message at speeds of up to 35 wpm, but I struggle to read light signals at 12 wpm. I have to sound out the light signals to make the connection in my brain so that I can decode the message. Just what you get used to I suppose.

Cazalet33
2nd Jul 2016, 00:54
Methinks "semaphore" is entirely the wrong word for the question.

Hydromet
2nd Jul 2016, 03:11
Glad you flagged that, Cazalet.

PingDit
2nd Jul 2016, 03:21
When we passed out from AEOp training we'd had to achieve 18wpm Morse and 8wpm with the Aldis lamp. I could easily manage 25 Morse and probably around 12 for Aldis. However, to remain in my own personal comfort zone about 18 for Morse and 6 for Aldis ensured very few errors. The golden rule was that you should only send as fast as the other operator was able to receive and understand. If you were getting too many requests for a repeat, you were sending too quickly.

John Hill
2nd Jul 2016, 08:29
I have some experience of Morse code but none with lights except one instance when a warship hailed us with what I thought was a string of 'A's. We hauled numeric signals for the HF frequence we had on board and they soon called us on that.

Regarding sending speed, I remember from when I was writing code for test Morse sending skills that most operators reduce the length of the long elements as they increase the speed and instead of the nominal 3:1 ratio many reduced to 2:1 before competent operators lost the ability to copy. You may see comments that computer systems cannot copy hand sent Morse code which is true if what is being sent is not really Morse code.

Gordy
2nd Jul 2016, 09:04
When in the RAAF, I had to recieve at 21 wpm, and send at faster....

Sallyann1234
2nd Jul 2016, 09:47
I can read morse comfortably at the speed sent by Barrington Pheloung.

Cazalet33
2nd Jul 2016, 13:32
I have some experience of Morse code but none with lights except one instance when a warship hailed us with what I thought was a string of 'A's.

Yes. AAAA is very commonly flashed from one ship to another. It means "I wish to communicate with you". It's often used when someone on the receiving ship has turned down the audio volume on CH16 VHF, usually because they've become so pissed off with having to listen to Greeks slagging off Phlilipinos and vice versa on that calling/distress channel.

John Hill
2nd Jul 2016, 13:53
Yes. AAAA is very commonly flashed from one ship to another. It means "I wish to communicate with you". It's often used when someone on the receiving ship has turned down the audio volume on CH16 VHF, usually because they've become so pissed off with having to listen to Greeks slagging off Phlilipinos and vice versa on that calling/distress channel.


It is very unlikely we would have heard any Greeks on VHF deep in the South Pacific.

ian16th
2nd Jul 2016, 14:18
Methinks "semaphore" is entirely the wrong word for the question.

Me too.

Way back when I was a Boy Scout, there was a method of sending morse with semaphore flags.
A short movement of the flag being a dot and a long movement being a dash.

Pontius Navigator
2nd Jul 2016, 15:57
John, why? :)

On the RCI cruise ship Adventure of the Seas, all the officers were Greek except the doctor who was Honduran and the cruise director who was Argentinean.

Many sailors working the ship were Filipinos.

John Hill
2nd Jul 2016, 18:46
John, why? :)

On the RCI cruise ship Adventure of the Seas, all the officers were Greek except the doctor who was Honduran and the cruise director who was Argentinean.

Many sailors working the ship were Filipinos.

VHF as you know is light of sight or a little more and I think we saw no more than a couple of ships in our two months or so voyage.

rans6andrew
2nd Jul 2016, 21:11
you might be right about semaphore being the wrong term for optical telegraph but I didn't know what is. I considered Aldis signalling but Aldis was just one variety of signal lantern.

Do enlighten us Cazalet33.