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Canadian_Guy_NS t1_iubrdlo wrote

I was a commercial radio operator. I qualified sending and receiving international morse at 20 words per minute.

Later, in the Military, I knew people who could receive at 60+ wpm. At those speeds you can hear whole words.

So, at the slower speeds, you have an element of time that is 1 unit. That is the length of a "dit", a "dah" is 3 units long. The space between the dits and dahs of a character is 1 unit long. The space between characters is 3 units long, or the space of a dah. As you get faster, the timing should stay the same, but what happens once you get proficient, the dits get shorter, and the dahs just become slightly longer dits, say 1.5x the length of a dit. Then you make the spaces within a character as short as possible, and shorten up the spaces between characters as well, but keep them slightly longer.

A good operator has a nice rhythm, and will work with the receiving operator up to that operator's most efficient speed. It is the rhythm that makes it all work. Think of it as like someone's speech cadence.

Also, most modern movies just have nonsense, and you don't hear the whole message because it would take too long.

dah ditditditdit ditdah dahkit ditditdit, ditditdahdit dahdahdah ditdahdit, ditdahdit dit ditdah dahditdit ditdahditdahditdah

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TwentyninthDigitOfPi t1_iuc9jbn wrote

How does the sender figure out the receiver's top efficient speed? Is there some sort of "hey slow down" or "go faster if able" code (formal or informal)?

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teh_maxh t1_iucndsc wrote

QRS to slow down, QRQ to speed up.

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Canadian_Guy_NS t1_iuf6g89 wrote

absolutely, if I was on a duplex circuit (two freqs) the receiver would send a dah, for every word received correctly, and if he wanted it resent, then send a ditdit.

People are lazy, so didn't really have to use Q codes in that situation, you just increased your send speed until either you weren't comfortable, or the receiver started asking for lots of repeats.

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GoodmanSimon t1_iue20ut wrote

Sorry, can I ask a sub-question that I think you can answer.

How did operator 'A' know the speed operator 'B' could read/understand?

I mean, by your example if one guy is firing 60 words a minute, how does he know he wasn't talking to 20 words per minute guy?

Ho about new guys? Were they all expected to understand 60 words per minute? If not... How would they tell the sender to slow down?

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the_original_cabbey t1_iuev3ay wrote

From what I’ve seen/heard so far, most folks if they don’t know the party on the other end will start fairly slow, and each response will be a little faster than the previous until one party or the other stops accelerating, or there is interference and they have to request a retransmission. But if they know each other, they’ll just start at whatever speed they are mutually comfortable at.

There are also a whole pile of three letter shorthands called Q-Codes. They act as meta or control instructions, and speed adjustments are one of the universal uses. They function in both a question and statement mode, and often have madlibs style fill in the blanks. Eg:

QRQ? Shall I go faster? QRQ40 Go faster, up to 40 words per minute.

QRS20 Go Slower, 20 words per minute max

QOD12? Can you communicate in English or French? QOD073 I can communicate in Dutch, Norwegian, or German.

QRE KRST? What is your estimated time of arrival at/over KRST? QRE KRST 0945 I will arrive at/over Rochester Intl. Airport at 9:45a UTC

There’s a pretty thorough list in Wikipedia: https://en.wikipedia.org/wiki/Q_code

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Canadian_Guy_NS t1_iuf63au wrote

Yes, pretty much. If you are on a duplex circuit, the receiver will throw a "dah" for each word received, and if they missed something in that word, will throw a "ditdit", and the sender will resend the last word.

When you are doing this style, you can quickly figure out how fast the other guy is.

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