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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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Configuring an antenna for (short distance) ground wave propagation on 40 m?

I'd like to use 40 m for short distance (ground wave) QRP CW. My criteria for antenna selection is simple: Works short distance (ground wave) As simple as possible As small as possible Ideally, some ...
SRobertJames's user avatar
1 vote
2 answers
58 views

Will a LPF filter on the transmitter prevent CW key clicks?

Reading about key clicks, it would seem that they are primarily caused by the fact that the square wave of turning the key on and off must, by definition, have higher frequency harmonics, which sound ...
SRobertJames's user avatar
1 vote
1 answer
43 views

What are the electrical properties and connectors of a CW key?

I'm working on a simple homebrew design and want to connect a CW key to it. (The basic design can use a simple built in pushbutton key, but I'd like to be able to purchase a proper key and use it as ...
SRobertJames's user avatar
4 votes
0 answers
65 views

A first homebrew design: Band, antenna, and ground wave propagation

I'm working on a very simple homebrew transceiver and request review of our selected band, antenna, and power. Background: A child got very interested in ham radio, as an incentive for to earn his ...
SRobertJames's user avatar
7 votes
2 answers
276 views

What is an undulator (as used for CW)?

There are historical references to a device called an "undulator" used for CW reception circa before and during WWII. What is an Undulator (as used for CW recording)? How did they work (...
hotpaw2's user avatar
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0 votes
1 answer
60 views

Help implementing a custom signal source in GNURadio for FMCW

I am trying to implement a custom signal source for FMCW in GNU Radio, but I am stuck. The idea is to generate a CW chirp signal using the formula $ \text{chirp} = \exp\left(1j \cdot 2 \pi \left(f_0 \...
Raj Patil's user avatar
1 vote
1 answer
177 views

Advice on keyer: two paddle on old Kenwood with 'straight key' only

I am using a Kenwood TS-130S, which has only a 1-pole jack for the key (it is a 1/4" telephone jack, aka "monoaural", tip and barrel only). I know that I need to have an aftermarket ...
Birdman's user avatar
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2 votes
0 answers
67 views

How can I key low voltage and still keep a tube VFO running constantly?

I'm interested in building a VFO based single tube CW transmitter. These devices are known to have issues with frequency drift and chirp; frequency drift can apparently be mitigated by ensuring ...
Zeiss Ikon's user avatar
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1 vote
0 answers
28 views

FT-818 - no xmit in CW

I have a nearly brand new FT-818. It works fine on digital modes, phone, etc. however, when I plug in a straight key, and key the unit, it never breaks squelch. I’ve checked the Breakin setting, ...
Marvin Gabriel's user avatar
5 votes
1 answer
183 views

Hearing impairment and CW?

Do there currently exist profoundly deaf operators who operate CW? If so, how does one operate without being able to hear a sidetone? If licensed in the U.S. before 2006, how did they pass the Morse ...
hotpaw2's user avatar
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1 vote
1 answer
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On KENWOOD TS2000, the CW messages don't record even after the "recording wait" pops up in the display. But the sidetone works fine

I'm working on a miniproject where i'm asked to demonstrate the recording of some signal. I made a keyer connection using a earphone cable to my Kenwood. The Keyer works fine - the sidetone is audible ...
Oviya Sankar's user avatar
1 vote
1 answer
164 views

Swapping crystal from HF to VHF in a QRP tranceiver

I am trying to build a short-range QRP weak signal VHF 2m CW transceiver. I found a small circuit that fit my needs, but it was made for use on 40m instead of my target frequency. The circuit included ...
Jayanta Pandit's user avatar
1 vote
1 answer
72 views

I have suddenly lost the ability to transmit CW on M IC-7200 xnxceiver. I am able to receive sigs but keyer does not work.makes dits but no dahs

My trusty IC-7200 has worked flawlessly for over 15 years but now I can't transit CW which is the only mode I work. I think something in the set for paddle connection is wrong. The directions in my ...
Jack Wooldridge's user avatar
1 vote
3 answers
212 views

QRP CW on HF using FT-817ND - filter/dsp recommended?

I'm just getting into amateur radio, so just starting to gather the things I want/need. I'm only really interested in CW, and almost exclusively on HF. I'm looking into a mobile/portable setup which ...
upasaka's user avatar
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1 answer
306 views

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 ...
Cliff-KU4GW's user avatar
3 votes
4 answers
1k views

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 ...
hotpaw2's user avatar
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3 votes
2 answers
129 views

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' ...
Bitbang3r's user avatar
  • 401
7 votes
1 answer
413 views

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 "...
Toby Eggitt's user avatar
5 votes
1 answer
767 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 ...
Aaron's user avatar
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6 votes
3 answers
1k 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 ...
Autistic's user avatar
  • 469
2 votes
6 answers
244 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 ...
soupwell's user avatar
2 votes
2 answers
256 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 ...
Edward Anderson's user avatar
1 vote
1 answer
110 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 ...
Skaiser's user avatar
  • 11
4 votes
4 answers
237 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....
EdvinW's user avatar
  • 378
3 votes
2 answers
585 views

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"...
SRoberts's user avatar
1 vote
1 answer
86 views

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 ...
Ture Pålsson's user avatar
5 votes
3 answers
1k 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 ...
rclocher3's user avatar
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2 votes
1 answer
617 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 ...
hotpaw2's user avatar
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6 votes
4 answers
2k views

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 ...
MacGuffin's user avatar
  • 359
2 votes
3 answers
2k 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 ...
Cimm's user avatar
  • 145
2 votes
2 answers
1k 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 ...
RiskyScientist's user avatar
0 votes
1 answer
101 views

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.
Gordon Jackson's user avatar
3 votes
3 answers
1k 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 ...
hotpaw2's user avatar
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4 votes
1 answer
201 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 ...
Aleksander Alekseev - R2AUK's user avatar
1 vote
1 answer
153 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 ...
joshperry's user avatar
  • 111
2 votes
2 answers
442 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 ...
user16406's user avatar
5 votes
3 answers
1k 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+...
Aleksander Alekseev - R2AUK's user avatar
7 votes
2 answers
2k 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: ...
Aleksander Alekseev - R2AUK's user avatar
9 votes
1 answer
1k 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 ...
hotpaw2's user avatar
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0 votes
1 answer
63 views

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 ...
kellogs's user avatar
  • 205
5 votes
1 answer
161 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.
rhonda oszczakiewicz's user avatar
2 votes
1 answer
273 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"?
Cardboard Box's user avatar
0 votes
1 answer
461 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 ...
hotpaw2's user avatar
  • 13.5k
12 votes
3 answers
914 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 ...
Amin Shah Gilani's user avatar
1 vote
1 answer
882 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 ...
hotpaw2's user avatar
  • 13.5k
4 votes
1 answer
956 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 ...
hotpaw2's user avatar
  • 13.5k
12 votes
1 answer
1k 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 ...
03525's user avatar
  • 221
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 ...
enocknitti's user avatar
6 votes
5 answers
2k 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?
Sumithran's user avatar
  • 583
2 votes
2 answers
1k 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 ...
Ben Madison KO4UXC's user avatar