All Questions
Tagged with on-off-keying or cw
127 questions
1
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3
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183
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How to test a simple homebrew CW transmitter - can I use an AM radio?
I've built a simple very low power (10-100mW) CW transmitter, and would like to test it over very short distances before working on my amplifier. (For background, please see A first homebrew design: ...
- 301
0
votes
2
answers
111
views
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 ...
- 301
1
vote
2
answers
74
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 ...
- 301
1
vote
1
answer
69
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 ...
- 301
4
votes
1
answer
154
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 ...
- 301
7
votes
2
answers
291
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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There are historical references to a device called an "undulator" used for CW reception circa before and during WWII.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 (...
- 13.6k
0
votes
1
answer
131
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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 \...
1
vote
1
answer
255
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 ...
- 11
2
votes
0
answers
83
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 ...
- 4,145
1
vote
0
answers
39
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, ...
5
votes
1
answer
215
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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 ...
- 13.6k
1
vote
1
answer
66
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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 ...
- 11
1
vote
1
answer
200
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 ...
1
vote
1
answer
114
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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 ...
1
vote
3
answers
240
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 ...
- 121
0
votes
1
answer
360
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 ...
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 ...
- 13.6k
3
votes
2
answers
147
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' ...
- 401
7
votes
1
answer
500
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 "...
- 383
5
votes
1
answer
843
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 ...
- 51
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 ...
- 479
2
votes
6
answers
267
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 ...
- 21
2
votes
2
answers
299
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 ...
- 185
1
vote
1
answer
118
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 ...
- 11
4
votes
4
answers
248
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....
- 379
3
votes
2
answers
635
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"...
- 43
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 ...
- 113
5
votes
3
answers
2k
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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 ...
- 9,320
2
votes
1
answer
701
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 ...
- 13.6k
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 ...
- 369
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 ...
- 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 ...
- 145
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.
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 ...
- 13.6k
4
votes
1
answer
214
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 ...
1
vote
1
answer
199
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 ...
- 111
2
votes
2
answers
488
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 ...
- 21
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+...
7
votes
2
answers
2k
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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:
...
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 ...
- 13.6k
0
votes
1
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65
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 ...
- 225
5
votes
1
answer
164
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.
2
votes
1
answer
281
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"?
- 123
0
votes
2
answers
527
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 ...
- 13.6k
12
votes
3
answers
965
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 ...
- 872
1
vote
1
answer
999
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 ...
- 13.6k
4
votes
1
answer
1k
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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 ...
- 13.6k
12
votes
1
answer
1k
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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 ...
- 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 ...
- 31
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?
- 583