Questions tagged [cw]

Continuous Wave (CW), or Morse code over audible tones. Use this tag for any question relating to Morse code.

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57
votes
16answers
6k views

Why is Morse Code still in use?

Why do people still use Morse Code? What are its advantages over newer Voice or Data communication modes?
31
votes
11answers
3k views

Are there well-known methods that can help improve my CW copying speed?

I've been having a hard time getting my Morse Code copying speed above 7-10 words per minute. Are there any techniques I can use to improve my skill?
17
votes
6answers
18k views

Using a Morse code key with a computer?

Are there standard ways to connect a hand key (straight or paddle) to a contemporary computing device (PC laptop with no parallel port, Mac, Android, iOS device, etc.) for developing or improving ones ...
14
votes
11answers
5k views

Is Morse code a digital, binary mode?

At first glance Morse code looks like a digital mode - there are dits and dahs, two values which contain the information of the transmission. Alternatively, at any point in time there either is a ...
14
votes
4answers
6k views

If I receive an SOS signal, what is the proper response?

My 5-year old son loves sending out an SOS signal using a toy Morse code generator (wired, don't worry about false alarms for real authorities). He has learned to send the SOS signal and was asking ...
14
votes
6answers
1k views

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

I need some recordings of CW / Morse code for use in a project. Most of what I find is either nonsense (it just exists for the 'sound of CW', but doesn't contain a message) or is generated by a ...
12
votes
2answers
2k views

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

I am studying for my FCC General Class license, and question/answer G4A02 reads as follows: Q: What is one advantage of selecting the opposite or "reverse" ...
11
votes
6answers
352 views

Key CW on zero crossings - zero bandwidth?

I remember being surprised to learn that a CW signal has a bandwidth (albeit small), but when I thought it over, it made sense. Essentially, we are modulating the carrier with a low frequency square ...
10
votes
1answer
968 views

Fastest Speed allowed for CW FM repeater ID in USA

What is the fastest legal WPM I can use for my repeater's Morse code identification? I am in the USA.
10
votes
1answer
136 views

Dominant speeds of Morse Communications

5 wpm is easy to learn and better than nothing in emergency. Speed Morse Coding is fine for "sport competition" I am trying to find out which is the typical speed for what I call "conversation" and ...
10
votes
2answers
578 views

Scoring quality of Morse Code “fist”?

When learning, teaching oneself, or training a class in Morse Code sending using a hand key, how can acceptable quality be scored (other than the letters being correct terms of dot-dash sequence)? ...
9
votes
2answers
2k views

Is Morse code allowed on FM in the USA

Let's say I get my little 2 meter FM handheld out and make a little sine-wave generator with which I pulse a morse code and if I connect it to headphones a speaker, I hear the dits and dahs of a nice ...
9
votes
3answers
6k views

Bandwidth of a CW signal?

What is the RF bandwidth of a typical CW signal? How is the signal bandwidth affected by WPM and/or transmitter rise-time? What is the narrowest bandwidth that can still be copied by a human? Or ...
9
votes
2answers
118 views

What is the purpose of the German CW exam if it is not required to use CW?

To receive the amateur radio license Klasse A (HAREC) in Germany it is since 2005 not required anymore to pass a CW exam, due to a corresponding change in the Radio Regulations. However, the exam is ...
9
votes
1answer
294 views

CW on phone band

In the U.S., regulations permit CW operations throughout the amateur bands. That makes the phone section of a band look tempting when the CW/digital part of the band is busy with a contest. I wonder ...
8
votes
3answers
1k views

What is the origin, history behind “Ben's Best Bent Wire”?

Bens Best Bent Wire My uncle, who was a Merchant Marine in WWII used to tell me this. He was a ham, and said it would develop my fist musically. I was a small child at the time, and through his ...
8
votes
1answer
3k views

Audio frequency used for Morse code in licensing exams?

Back when Morse code proficiency was required for certain radio licenses, what audio frequency was used by the exam tapes, equipment or examiner that generated the Morse code audio? Was there a ...
7
votes
5answers
3k views

Should I learn morse at “both” speeds?

There are many anecdotes of hams learning Morse Code at e.g. 5wpm and then "hitting a wall" trying to gradually speed up to 15wpm. David G. Finley, N1IRZ claims the reason is this: Morse at 5 wpm ...
7
votes
6answers
4k views

International characters in Morse Code?

Does the official International Morse code include alphabetic characters other than the 26 letters of the English alphabet? If so, what are the most common other alphabets or characters that one ...
7
votes
4answers
660 views

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

In Morse code, hams use "hi" to indicate a laugh, and "es" to mean "and". Where did these abbreviations come from? Both being all dots, they are short and easy to send and easy to recognize, but why ...
7
votes
2answers
173 views

Are there any rules/conventions for transmitting coordinates in CW?

I am wondering how hams transmit coordinates in Morse code. Considering that coordinates can be represented in many different formats (such as DD, DDM, DMS, WGS84, etc.) and that an error in the ...
6
votes
5answers
2k views

Is Morse code a requirement for ham licensing?

As I recall, it used to be in the U.S. that the ability to read and send Morse code over CW was a requirement for an amateur license (and was tested, I believe). Is that still true in the U.S.? If ...
6
votes
4answers
809 views

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

I ended up with an old straight key that has a curious feature: below the main arm that you would tap on, there's an extra metal flange that can sort of loosely pinch an extra sliding lever underneath,...
6
votes
4answers
2k views

Single or Dual Paddle Key?

I want to eventually use a CW paddle and built in keyer in my Yaesu FT-890. What are the merits of each style. Single or Dual Paddle. Does it make any difference if I start with say a dual paddle then ...
6
votes
4answers
607 views

How many new amateur operators can currently use CW?

Given that it is no longer a license requirement, are there any current statistics available on what percentage of licensed amateur radio operators still learn Morse Code to some degree of proficiency?...
6
votes
3answers
246 views

How do I send negative numbers or below zero in CW?

Sometimes when operating CW I want to send numbers that are negative. In particular when operating outdoors during the winter and someone asks the temperature, I would like to come back in CW with -...
6
votes
1answer
607 views

Coherent CW synchronization?

When using coherent CW, how is the receiver frequency and/or Morse Code dot clock synchronized to the transmission precisely enough to allow for synchronous decoding?
6
votes
2answers
2k views

Configuring an SDR for CW?

So I'm developing my own SDR software from scratch (I like to "own" the code). The channel between the RF-to-USB hardware and the software is 192kHz sample-rate IQ audio samples. The degrees of ...
6
votes
2answers
111 views

Is CW necessary to be competitive in most ARRL contests?

The ARRL hosts many contests throughout the year, and maintains a leaderboard of sorts to encourage competition. Is it possible to rank on any of the leaderboards without knowing or using morse code?
6
votes
2answers
2k views

Preventing CW key clicks

What are "key clicks"? How much does the rise time or bandwidth of a CW signal need to be limited to prevent other QSOs on adjacent frequencies from being annoyed by "key clicks"? Is there a legal ...
6
votes
3answers
446 views

Morse Code Key Grease

I just got an old brass key at a hamfest, and it appears to be in pretty good mechanical condition, aside from some dirt and dust. Taking it apart, the key (apologies for not knowing the exact ...
6
votes
2answers
485 views

Morse Code meta-command sequences?

When using Morse Code as an accessibility/disability communication or input method, are there any non-alphanumeric dot-dash sequences that are more common or more suitable for meta-commands, such as “...
5
votes
4answers
294 views

Are QRP transceivers only meant for CW communication?

I was just thinking about making a QRP transceiver, but are they only used for CW (Morse code) communication? If it is so, can I modify a QRP for two way audio communication?
5
votes
4answers
527 views

What if someone responds to my CQ, but I can't hear him?

I tried making a CQ on 20 m, 14.060 MHz (the QRP CQ frequency) and parallel to that I had a WebSDR on my computer just to keep an eye on the band. I saw someone responding on the WebSDR, which is ...
5
votes
2answers
244 views

What does QSL mean in a CW conversation?

When the other party sends QSL, do they just want to know whether I received the previous message and expect RR or ...
5
votes
3answers
730 views

How slow is slow telegraphy?

On the UK Band Plan there are frequencies stating “QRS (slow telegraphy) Centre of Activity”. For example, 14,055 kHz on 20m and 3,555 kHz on 80m. What is considered slow? (<15 wpm?) How close ...
5
votes
6answers
19k views

How to convert a Morse Code Message/QSO from Mp3 file into text?

I tried to use both: Cwget CW decoder But neither one worked. Can you recommend a tool or an alternative approach to decode a Morse message saved as an Mp3 file?
5
votes
4answers
2k views

Shaving Quartz Crystal for New Frequency

Back in the 1960s during my Novice days I operated on the 40-meter band only with 4 different quartz crystals that determined my transmitting frequency with my Eico 720 CW transmitter. I had heard ...
5
votes
3answers
361 views

Characteristics of a “bad fist”?

What are some characteristics, when sending CW, of a "bad fist"? How bad can it get, typically, and still manage to communicate the message text sent to a human operator on the receiving end? Contra-...
5
votes
2answers
137 views

Air gapped digital communications mode on VHF?

According to this question MCW (modulated continuous wave) is allowed on large portions of the VHF bands in the U.S. Is using MCW suitable for passing small amounts of digital data between 2 PCs or ...
5
votes
3answers
2k views

How are capital letters sent in Morse code?

There is only one alphabet in Morse code, so is there a recognised way to indicate a capital letter?
5
votes
2answers
399 views

Circuit to send MCW on 2m FM

I regularly practice Morse with a friend on 2m NFM by holding our tone generators, which we also use for personal practice, close to the microphone. We send text by CW, read it back, and discuss how ...
5
votes
2answers
2k views

What is the record for the highest non-automated over-the-air CW WPM speed?

Related to this question, but using humans, and in an actual QSO, not lab conditions: Is there a record for QSO QRQ speed? And, if so, what is the record for the highest non-automated over-the-air ...
5
votes
2answers
239 views

Has anyone actually heard or used rare Morse code characters on the air?

When I got my license about 50 years ago, I believe the only punctuation marks on the test were the period, comma, question mark, and slash mark. Once on the air, I heard and used the usual prosigns, ...
5
votes
1answer
240 views

History and significance of term “lid”

What is the history on the term “lid” when referring to a telegrapher’s capability? How did it originate and what is the significance if any of each letter?
4
votes
1answer
97 views

Will I get cleaner keying by keying the oscillator, or interrupting the amplifier B+?

One of my goals as a new ham is to homebrew my own transmitter (using vacuum tubes, aka valves). Initially I'll stick with CW for the transmitter, though over time I might build an AM modulator or ...
4
votes
1answer
83 views

Is a US Extra class exam from the '90s valid to upgrade from Advanced class today?

If one passed the Extra written test in the late '90s at an ARRL test center but did not get the 20wpm endorsement, yet is an Advanced operator, would they now be upgraded to Extra class or do they ...
4
votes
1answer
223 views

Listening below the carrier frequency gives a weaker signal than above the carrier frequency - why?

I have a 20m CW transceiver with an option for a wide or a narrow filter. When the narrow filter is selected, a crystal ladder filter is used in the intermediate frequency filter, between two mixers. ...
4
votes
1answer
182 views

What would letter T mean in this radio beacon message?

I'm currently picking up signal from a beacon using RTL-SDR and decoding the Morse code on a computer using gMFSK program. The beacon is sending message which decodes as "T DE YU1VHF LOC KN04OO". I ...
4
votes
3answers
2k views

How low a sidetone frequency will allow QRQ CW to be copied?

What sidetone frequency range (or VFO/BFO receiver offset) will allow one to copy CW when trying to learn to copy QRQ? (high-speed Morse code, 40 WPM and higher) It seems like there will be very few ...