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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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6
votes
5answers
915 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,...
9
votes
2answers
149 views

What is the decimal in Morse Code?

The ITU's International Morse Code recommendation ITU-R M.1677-1 specifies a "Full stop (period)" as ".−.−.−", however it falls short of specifying a decimal point. Even the examples, though they ...
1
vote
1answer
40 views

Wiring a CW paddle and straight key to a TRS connector?

Some transceivers come with a TRS plug input labeled "key". When wiring my paddle or a straight key for these TRS connector inputs, is there any current standard for which key connection goes to ...
3
votes
1answer
66 views

CW skimmers and spotting networks?

What are CW skimmers, especially with regard to spotting networks? Are there more than one (of each)? How do the skimmers interface with spotting networks? (Or are they combined into a single ...
2
votes
1answer
162 views

How does this circuit work? Why is the antenna connected to the output of the amplification stage?

What is the function of the configuration of R1, C3,C10 and R3? How does the LC tank in this circuit work?
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 ...
2
votes
3answers
723 views

How to use a Linux computer as a paddle key code practice oscillator

I'm working on learning Morse code, and I'm looking for a way to use my computer as a practice oscillator with a double paddle key. I'm using a Linux PC, but a Raspberry Pi solution would be cool to. ...
6
votes
4answers
661 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?...
58
votes
16answers
7k 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?
10
votes
1answer
152 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 ...
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 ...
2
votes
6answers
2k views

Is this strange Morse signal type common?

I, just as a hobby project, am writing a program for decoding Morse code. I am not a ham, but generally interested in radio and programming. I have a first version of the project, but it failed to ...
5
votes
4answers
367 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?
1
vote
1answer
72 views

Problem recording morse with sdr#

I have a problem with recording SWS-morse using SDRSharp and RTL-SDR. I want fixed gain, not audio automatic gain control. The problem is that all signal but the weakest will cause the recorded audio ...
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?
5
votes
2answers
265 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 ...
2
votes
2answers
173 views

How does keying a CW transmitter work?

In my handbook it talks about keying the transmitter to produce the dots and dashes. Does this mean that the operator is turning the transmitter on and off, or does this mean that the key is turning ...
0
votes
2answers
122 views

If I send periodic SOS and nothing else, what would be the response by hams and/or government?

TL;DR: If I blast out a periodic SOS, what rescue action should I expect? Similar to if I activated an EPIRB, or something less? This question is inspired by If I receive an SOS signal, what is the ...
7
votes
4answers
771 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 ...
4
votes
1answer
117 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 ...
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 ...
15
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 ...
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 ...
5
votes
2answers
249 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, ...
2
votes
2answers
348 views

How to transition CW ability to listening instead of simply copying - software assist?

I was recently reading this article from the ARRL web site, Morse Code at 140 WPM (ARRL) about Chuck Adams, K7QO, who claims to be able to handle this speed all by himself. Very interesting article....
3
votes
2answers
102 views

Do MRI machines use the ISM band, and do they generate audible CW signals?

I've recently had an MRI, and after studying chapter two and three of the ARRL manual, I've got a better understanding of how my MRI machine might have worked. Now, I am curious to know what would ...
0
votes
2answers
129 views

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

I've been reading about the history of telegraphy, and I knew that back then radio signals were produced in massive strength by using powerful dynamos and magnetos, with a telegraph key to interrupt ...
3
votes
1answer
128 views

Why were “PARIS” and “CODEX” considered “typical words”?

In the context of wondering how to convert characters per minute to words per minute, it was pointed out that CODEX and PARIS are used as typical words for measuring speed of CW operators. As the ...
2
votes
1answer
1k views

Converting WPM to CPM

I'm using an Anroid app for learning CW. In Germany, it's common to define the speed in CPM ("characters per minute", or German BPM for "Buchstaben pro Minute). However, the Morse trainer I use ...
9
votes
2answers
122 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 ...
5
votes
1answer
84 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 ...
6
votes
1answer
632 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?
3
votes
1answer
1k views

Yaesu FT-450D CW from computer - DATA and CAT connectors

Yaesu FT-450D Transceiver USB-to-DB9 cable installed to the CAT interface Computer runs the ADMS-450 channel-programming program fine. Computer can run the PCC remote-control program fine. DATA ...
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 ...
6
votes
2answers
1k 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 “...
17
votes
6answers
19k 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 ...
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 ...
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" ...
1
vote
1answer
225 views

Morse code in a puzzle

I'm working on a morse code geocache puzzle. Firstly I had to listen to Morse code and I got the following words from it SYGYO UMPET KUSIK MUMWY MOPPE MACOP TUGNY WAAXT MUFAJ MIAMG TUGND I suspect ...
11
votes
6answers
387 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 ...
7
votes
2answers
200 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
3answers
254 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 -...
1
vote
1answer
84 views

“;” in morse “-.-.-” or “-.-.-.”? [duplicate]

What is the correct sign for ";" in morse? FLdigi converts "-.-.-." to ";" whereas in various code lookup tables I see "-.-.-" Can both be used or is one of the morse codes valid?
3
votes
4answers
460 views

What's this maybe-morse-code “CQ CQ GE EDEN” and “DD” in Le Eden de la Grisaia?

The ending song of an anime television series called Le Eden de la Grisaia here has a light flashing. I suspect it may be Morse Code. By watching the video a little more slowly than usual (frame by ...
2
votes
1answer
3k views

Decoding the Morse code

I am using a crystal to transmit morse codes, and I am using Kenwood radio receiver to obtain the signal. It receives the signal with a lot of noise, though we can figure out the morse code sound. I ...
3
votes
1answer
461 views

Difference between Iambic keyer modes?

What is the difference between Iambic Keyer mode A and mode B? Are there any other popular keyer modes? Why would one choose one mode over the other? If only one Iambic keyer mode is to be ...
5
votes
3answers
767 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 ...
2
votes
4answers
259 views

CW “training” recordings

I'd like to get some recordings of typical receiver audio output of HF CW transmissions. I'd like to both train my mental copying capabilities and look into improved automatic (software) CW ...