Questions tagged [cw]

Continuous Wave (CW), the modulation mode of switching a carrier on and off to encode information, or sending Morse code tones over AM or FM modes. Questions that are about Morse code alone and not about radio at all, such as a question asking about some Morse code in a movie, should use the "morse-code" tag instead. Questions about keying a radio should use this tag. Questions about Morse-code-related radio procedures, e.g. Q-codes, should use this tag.

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Best CW Low Cut & High Cut Slope Settings on the Yaesu FT-991A?

I am running a Yaesu FT-991A and am wondering which low and high cut slope settings would be the better to use on CW mode as far as making sure I don't get key clicks. The default menu # 051 = CW LCUT ...
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1 vote
2 answers
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POTA and SOTA Spotting networks?

How do spotting networks specific to POTA and SOTA activities work? ("parks/summits on the air") Are POTA and SOTA spotting networks a subset, a superset, or a completely different network ...
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3 votes
2 answers
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how to sink 9-15v under control of 5v or 3.3v pin to 'key-down' transceiver?

I want to use an Arduino to control keying transmission on a simple CW-only transceiver (think: forty-9er or Pixie). Looking at the schematics of various such transceivers, they basically 'key down' ...
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6 votes
1 answer
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Simple circuit for acceptably clean CW in homebrew TX?

I'm working on a design for a home-brew 10 metre transmitter for CW. My oscillator is running cleanly, and I need to add a (small, probably 1/2 ~ 1 Watt) power stage to it, and I need to "...
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5 votes
1 answer
334 views

bizzare CW on 2m

I'm currently in Kershaw, SC. Yesterday an automated signal popped up on a 2m simplex freq (147.455 MHz) and has been running since. It sounds like Morse, but it is random letters that don't seem to ...
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5 votes
3 answers
358 views

Transmitting Morse Code as Tone vs. Carrier

Normal CW is just carrier on/off; this means simple transmitters are possible. The BFO of the receiver is adjusted to give a tone in the speaker within the audio passband. Narrow band filtering is ...
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2 votes
6 answers
186 views

Looking for a way to create a radio link between a pair of antique telegraph keys

I'm trying to design a way to link up two antique telegraph keys wirelessly. This is for a friend to use with his granddaughter between the house and the playhouse, so we plan to use FRS to avoid ...
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2 votes
2 answers
93 views

Connecting a Katsumi Elekey EK-150 to my transceiver

I picked up a used Katsumi Elekey EK-150 (manual) electronic keyer. I'm trying to get it working with my Kenwood TS-570S (manual), which has a 3.5mm Key jack. With a male-male audio cable connected to ...
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1 vote
1 answer
70 views

CW speaker and volume control

I'm building a kit for the LNR precision mountaintopper 3 band qrp radio. I'm having problems wiring a panel mounted volume knob and speaker to hear the cw output. I'm new to home brew electronics ...
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4 votes
4 answers
178 views

Could keying cw with your mouth using a sip-n-puff be as efficient as doing it by hand?

I know Morse code is sometimes used by people with limited use of their hands to interact with their computer. One way is by using a straw connected to a pressure sensor, a so-called sip-n-puff or SNP....
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3 votes
2 answers
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what am i listening to when i listen to morse code?

morse code signals are only carrier waves, right? so a transceiver transmits a 14 MHz wave, unmodulated, or nothing at all. but i can't hear 14 mhz. i know my radio plays a 700 Hz "side tone"...
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1 vote
1 answer
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Sunspot numbers? forecast? broadcast on CW/HF

I have vague memories from the early 1990:s of some sort of service that broadcast something related to sunspot numbers, in CW, probably shortwave. I think the world "BOULDER" was in there ...
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5 votes
3 answers
631 views

Why are contest signal reports always "59" or "599"?

I've heard lots of contest exchanges, and the signal report almost always seems to be 59 for phone or 599 for Morse, even when the operator giving the report has to request information to be repeated ...
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2 votes
1 answer
286 views

What is an Audio Peaking Filter?

What is an Audio Peaking Filter? And how might that be different from an ordinary (narrow) CW bandpass filter, or from tunable audio filters (with fully configurable upper and lower cutoffs)? Does a ...
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4 votes
4 answers
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What nations still require Morse code testing for Amateur radio license?

Going a bit further I'll ask, for which licenses (all or just for licenses for HF operation) and at what speed (5 WPM, 10 WPM, none specified)? The reason I ask is because every so often I'll see ...
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1 vote
3 answers
831 views

Why can I hear Morse when not in CW mode?

I don't "get" CW. I can't understand the chatter on an FM radio broadcast when my radio is set to AM. This makes sense, the signal is modulated using frequency modulation and I am trying to ...
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2 votes
2 answers
668 views

What is the current state of the art in CW filters?

In the 1970s I made a CW “filter” based on a phase locked loop that detected a specific audio frequency, and this drove an NE555 oscillator: the result seemed at first like a “zero bandwidth” CW ...
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1 answer
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FT450D no cw tx unless ppt is held

FT450D in cw mode does not transmit unless PTT is actuated. "BK-IN" not in display despite pressing function followed by vox/store button.
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3 votes
2 answers
483 views

Maximum legal QRQ CW speed?

Computer generated and decoded Morse Code seems to be a not-uncommon operating practice in the HF bands. Given this, and that there's no reason why Morse/CW signals can't be synthesized and decoded ...
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4 votes
1 answer
133 views

How proper HIHI sounds like?

Recently I've read Zen And The Art Of Radiotelegraphy by Carlo Consoli, IK0YGJ. I must say, it's a great book, and as a new CW operator I've found plenty of useful information in it. What especially ...
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1 vote
1 answer
81 views

Info on this Bunnell J-38 key

I've been trying to find manufacturing date info on the J.H. Bunnell key ("J.H. Bunnell&Co" is stamped on top of the frame), but it seems to be somewhat unique. Most J-38 keys that I've found ...
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2 votes
2 answers
221 views

What is NR and a number instead of city and state after my QTH?

I have been a ham for almost 20 years, and when on CW I have always sent my call, name, RST, and full QTH. I have noticed that now many operators send NR 5280 or something similar instead of their ...
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5 votes
2 answers
444 views

What gain and power are required for successful DX contacts on 2m/70cm bands in CW?

I would like to practice in CW on 2m/70cm bands when and if there will be a tropospheric or sporadic-E propagation. However I don't have mush space for the antenna. There is a possibility to install 3+...
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7 votes
2 answers
845 views

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

I'm new to CW and one thing I couldn't figure out is when I supposed to send "E E". Let's say I'm calling CQ and somebody answers me. The QSO is almost over. Should it be ended like this: ...
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9 votes
1 answer
638 views

Calculating the signal-to-noise ratio for CW (Morse Code) signals?

How is the signal-to-noise ratio for received CW and QRSS CW (and/or other ultra narrow-band DSP digital modes) typically computed? e.g. What noise bandwidth should be used to measure the spectrum ...
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1 answer
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Both OOK and FSK used in the same transmission

My gas burning heating unit takes its temperature readings from a 433 MHz thermostat, which is emitting precisely the same data packets in a packet train at some ~100 ms interval like this: 2 x OOK ...
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5 votes
1 answer
147 views

Last Morse call for Thomas?

What does this mean: CQ de KYHP QTC? K My father-in-law was a radio operator in the merchant marines during WWII — this was his last writing.
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2 votes
1 answer
180 views

Repeater identification ending (CW)

I am just starting to learn CW, and for practice I have been recording and transcribing repeater identifications that I hear. This is what I heard today: DE W9KIC/R BBG What is the meaning of "BBG"?
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0 votes
1 answer
226 views

What is the most common CW audio filter center frequency?

For older receivers with a fixed (crystal?) audio filter for CW, what is the usual center frequency of the audio bandpass of the filter? Or cut-off frequency for low-pass CW filters? For newer ...
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11 votes
2 answers
602 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 ...
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1 vote
1 answer
327 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 ...
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4 votes
1 answer
656 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 ...
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11 votes
1 answer
635 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 ...
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2 votes
6 answers
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 ...
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6 votes
5 answers
1k 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?
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2 votes
2 answers
671 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 ...
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2 votes
2 answers
174 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 ...
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8 votes
2 answers
526 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 ...
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1 vote
1 answer
102 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 ...
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4 votes
1 answer
345 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 ...
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16 votes
5 answers
11k 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 ...
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3 votes
2 answers
142 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 ...
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0 votes
2 answers
633 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 ...
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4 votes
1 answer
331 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 ...
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9 votes
2 answers
179 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 ...
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15 votes
11 answers
7k 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 ...
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5 votes
1 answer
112 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 ...
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3 votes
1 answer
5k 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 ...
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8 votes
2 answers
498 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 ...
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6 votes
2 answers
369 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, ...
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