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21 votes
Accepted

Is Morse code a digital, binary mode?

According to Shannon (in A Mathematical Theory of Communication - and who's going to argue with Shannon?) there are really only four symbols in Morse, not five: "dit" (defined as one unit time on ...
19 votes
Accepted

How does selecting the opposite sideband when receiving CW on HF reduce interference?

CW signals are not “transmitted on the upper sideband”, nor the lower one. A CW signal is approximately at a single frequency (with only the additional bandwidth required to allow the key-up and key-...
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19 votes
Accepted

Why do some straight keys have a slider that shorts the contacts continuously?

My understanding is that in at least some telegraph systems, the principle of operation was as in this circuit (where the coils depicted are actually telegraph sounders): simulate this circuit –...
  • 23.2k
12 votes
Accepted

What was the origin of the Morse code abbreviations "hi" and "es"?

Many Morse abbreviations and conventions come from before the days of radio, and we are relative latecomers to the game compared to the telegraphy guys. For this question, I found an old reference ...
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12 votes
Accepted

What does QSL mean in a CW conversation?

Generally, QSL means "I acknowledge receipt". "QSL?" (with a question mark) means "please acknowledge". Sometimes when listening to QSOs you will hear someone say QSL VIA BURO or QSL DIRECT or ...
  • 4,419
11 votes
Accepted

Where can one find recordings of Morse code, generated by humans and not machines?

Try to find the allocated amateur radio band plans for your country. You will notice that there are reserved sections of the band plan that are for CW only. Usually they are in the first few kHz (i.e. ...
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11 votes

Why is Morse code still in use?

Because it's fun to send and receive messages by Morse code! It's something that can be done without any specialized equipment for sending and receiving. It's a shared historic experience. It's a ...
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11 votes
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If I receive an SOS signal, what is the proper response?

Since you're simulating the situation with non-transmitting equipment, you get the play the part of actual emergency agencies. You'd start by asking the SOS caller to identify themselves (call sign, ...
  • 3,901
11 votes

Is this strange Morse signal type common?

That is Morse code, in Norwegian, being sent with a "bug" (Vibroplex type mechanical key). The two operators are LA6UH and LA7JS. Probably not something you want to figure out how to decode with a ...
  • 7,713
11 votes

Dominant speeds of Morse Communications

Data from the Reverse Beacon Network provides an answer. RBN receivers and computers decode CW (and other "digital" modes) to identify stations calling CQ and posts information about signal strength ...
  • 7,713
10 votes

Why is Morse code still in use?

I love Morse code for these reasons: It's fun. There is something satisfying about pulling a really weak signal out from the noise just 10s of Hz away from another really strong semi-local signal, ...
  • 4,419
10 votes
Accepted

What is the decimal in Morse Code?

In the International Code of Signals (an International system of maritime communication, including radiotelegraphy), AAA (over-bar) is designated for both full stop and for decimal point. (See ...
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10 votes
Accepted

CW: when I supposed to send "E E"?

First, some history. As I understand it, the "dit-dit" (E E) comes from an old practice. There is a short tune in popular music that was often used to end a musical performance in a humorous way, ...
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9 votes
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Morse code for hash (#)

There isn't one. Why? Because it's not defined in the standard. "#" isn't the only symbol in common computer use which is not defined in Morse code. For example, Morse code can't distinguish upper ...
9 votes

Single or Dual Paddle Key?

Single-lever paddles have a single lever that generates dots when pressed to one side, and dashes when pressed to the other. Dual-lever paddles have two paddles, one of which generates dots and the ...
  • 8,942
9 votes
Accepted

Are QRP transceivers only meant for CW communication?

QRP only means low power, often 1W or less. While you could technically have a 1W SSB transceiver and call it QRP, the practical range of such a radio would be limited. It is much easier to hear a ...
8 votes
Accepted

Using a Morse code key with a computer?

A really easy way to do this is to take an old USB mouse (or even a new cheap one) and solder the key across the left mouse button. You can then use key directly as mouse button input on most ...
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8 votes

Why do some straight keys have a slider that shorts the contacts continuously?

Land line telegraph keys are fitted with a circuit closer switch. Radio telegraph keys were not but many radio operators used land line keys because they were so readily available. This includes the ...
8 votes
Accepted

Why do CW signals get converted to pure sine wave tones at 750 Hz?

The tone you hear when receiving a CW signal is generated inside your receiver. Originally, a motor-driven variable capacitor or interrupter was used to put an AC component into the detector circuit, ...
  • 3,901
8 votes

What does QSL mean in a CW conversation?

Especially true in a contest, or noisy environment: Hearing a "QSL?" from someone can mean they want to know specifically if what they've sent to you has been sent correctly. They may have been ...
  • 1,013
8 votes

What is the decimal in Morse Code?

The web sites of Kent Morse Keys and of the AC6V reference compendium document use of the Morse letter 'R' (dit-dah-dit) as an abbreviation for 'decimal point.' 'R' can have other meanings, of course, ...
  • 7,713
7 votes

Why is Morse code still in use?

It was all I could afford when I was a kid. AM and SSB gear was expensive and still is! Stuck with it because: Signals are stronger, More of a challenge, and a CQ gets answered faster. Great people on ...
  • 71
7 votes

International characters in Morse Code?

È grave •-••- (ex) (French) or È grave or ••-•• (el) (Italian) Ë diaresis or ••-•• (el) Ę hook or ••-•• (el) (Polish) É acute ••-•• (el) (French, Spanish) or É acute or -••-• (xe) Here's a list of ...
7 votes
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Decoding the Morse code

If you would like to decode Morse code with an existing program: My personal recommendation is Fldigi, which is a software modem that runs on most major operating systems, including Windows and Linux....
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7 votes
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CW contact content

Didn't you need to study basic contact procedure for your license? In any case, my advice for situations such as these is simple: Listen! Since you have a transceiver, just listen and try to find ...
  • 2,715
7 votes

Do I need a Balun for a single band QRP antenna?

You don't need a balun, in that it will work and it won't hurt you. But your antenna will not work as well as it ought to. When you are transmitting, the effect of a balun used to connect a coax (...
  • 23.2k
7 votes

Is Morse code a digital, binary mode?

The mode hams call "CW" is also called "on-off keying" (OOK) - a hint to the fact that it is a binary code. Dots, dashes and spaces are usually sized in multiples of the "dot time": one dot time on ...
  • 7,713
7 votes
Accepted

Why can I hear Morse when not in CW mode?

You don't say where you are hearing the Morse code. You say "on the same channels", but don't specify where you are listening. If you send Morse code using a buzzer, then that generates an ...
  • 4,419
6 votes

How many new amateur operators can currently use CW?

From my experience, not many. Not many at all. Learning CW at speeds that facilitate conversation, vs just sending callsigns and signal reports, is, frankly, daunting. I've only been a ham for a few ...
  • 61
6 votes
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Characteristics of a "bad fist"?

Some characteristics that make code harder to copy: The dahs are are too short compared to the dits. Not enough space between words. Not enough space between characters. An out-of-place pause when ...

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