為什麼仍在使用摩爾斯電碼?


60

為什麼人們仍然使用摩爾斯電碼?

與較新的語音或數據通信模式相比,它有什麼優勢?

22

One of the reasons it's still in use is because of its inherent simplicity - no real signal processing is needed. Thus, CW transmitters and receivers are very simple and thus inexpensive.


35

The advantage? Efficiency! You get to put all of that power of your rig into a very small bandwidth, whereas voice modes need to spread the power out much more (for example, SSB uses roughly 2.8kHz of bandwidth).

Quote from: http://home.windstream.net/johnshan/cw_ss.html :

Going a little bit further, assuming a SSB signal takes up 2000 Hz., and comparing a 100 watt 25 WPM CW signal with a 100 watt SSB signal, we have the following. The average power density for CW is 100W / 100 Hz. or 1 w/Hz. For SSB it's 100W / 2000 Hz. or .05 w/Hz. Follow closely now, it gets interesting although a little more technical. We could say that the gain in using CW over SSB is Gain(db) = 10*log(1/.05) which is about 13db. That means that a 5 watt CW signal packs an equivalent punch to a SSB signal at 100 watts.


71
  • because there are a large number of operators who had to learn it to get their licence
  • because there is a large (but slowly diminishing) number of operators who learned it while serving in the armed forces
  • because the transmitters and receivers can be extremely simple and inexpensive, not needing much more than a key and headphones along with the rig, antenna and battery to send and receive
  • because (in theory) it has a very tiny bandwidth, allowing small QRP transmitters to send a very effective signal. This also allows a large number of contesters to cram into a few kilohertz of bandwidth, each (with suitable filtering) able to be picked out individually
  • because it's a point of pride for some operators that they know this thing that the young 'uns don't.

CW can be sent exceptionally well by computer (with software like fldigi) or by any number of USB/serial keyers (such as the WinKeyer or K3NG Arduino keyer). It can be copied reasonably well in software (fldigi again, or CW Skimmer). The Reverse Beacon Network relies on multiple stations worldwide running CW Skimmer to report on propagation, and will show you where your CQ has been copied.

It can be thought of as a digital mode, but one that can be copied by ear with sufficient training. It's typically a little slower that PSK-31 or RTTY, and CW only supports a very limited single-case character set. Although it is no longer used commercially or by the military, it's likely to stick around in ham radio for a long time.


8

In noisy conditions, CW is the most effective mode for "real time" communications. This is the primary reason that CW remains popular with DXers.

Some digital modes can succeed under even worse conditions, but they do so by employing redundancy, which makes for very slow QSOs.


7

In the UK, the terms of the licence start with:

1(1) The Licensee shall ensure that the Radio Equipment is only used: (a) for the purpose of self-training in radio communications, including conducting technical investigations; and (b) as a leisure activity and not for commercial purposes of any kind.

CW/morse lends itself to the self-training aspect due to the simplicity of the equipment required.

For example, in the Summits on the Air program, there is an ongoing PP3 challenge - which making the most QSOs using one PP3 type 9V battery. This is only possible by operating on very low power, and using CW. OK, this is only for fun, but that is what most of us are in amateur radio for, are we not?

Personally, I haven't mastered CW (yet?) but I am quite impressed to watch/listen to operators working the key...


21

One of the biggest advantages of CW is that users worldwide can contact each other without knowing English, or any specific language. Conversation is limited to the common Q codes, but these provide significant flexibility and ability to communicate making Morse Code a common language of sorts.


9

Morse code requires an extremely small bandwidth (and is usable in a channel that has a relatively low S/N) for a mode that requires no digital processing hardware or computer/digital logic chips (instead requiring just the skill of a couple of human brains) to communicate. Some people value accomplishing things using personally learned skills rather than software and DSPs/CPUs designed by others.

A legal Morse code transmitter is about as simple as possible as that which can be constructed from basic analog components, although a CW receiver might require more parts than for AM (not sure about a pure regenerative receiver design).

Morse code is also a useful cross-over skill that could potentially be very useful to have in certain survival or medical situations, such as signaling by mirror when lost in the woods, eye blinking when partially paralyzed (or captured behind enemy lines), using one-button or blow/puff controllers by the severely disabled, etc.


9

I am a new ham, and I decided to learn it, and use it, strictly for the purpose of efficiency. CW operation is low bandwidth, and therefore requires very little power to get a signal out over long distances. You will not get the same results from voice transmissions or other larger bandwidth data modes (although JT-65A and PSK31 are relatively efficient data modes). It's very gratifying to work around the world with ease in CW mode, whereas doing so in voice is doable, but a lot more difficult. The best advantage I can think of over other data modes is that you don't need to depend on a computer or external device to create Morse code messages. It's a human rendered data mode.


5

Morse code is a raw and ancient way to deliver a signal to its destination. Even in case of non-digitised communication, Morse code is a way to express signal. The science of this is known to all telecommunication personnel, and thus is still used in many cases. It is also easier to create than a digital code.


8

I got my technician license in 1992 to play with packet and TCP/IP on VHF/UHF. I got bitten by the HF bug listening to the CW subbands. I decided to learn CW on my laptop on business trips. I struggled to pass 5 WPM for my Tech-plus but I did and I got on 80m CW. A few months later I had WAS and It wasn't long after that I passed 20 WPM for my Extra.

Why do I operate CW? It is a blast!


9

I would echo the point mentioned by N8WRL: "Why do I operate CW? It is a blast!"

I'm actually re-learning morse and realising I've been missing out on a lot of fun over the years.

In terms of learning and training, it feels some way between learning a musical instrument and learning a new language. It is an excellent way to stimulate the brain - an investigation into morse-related neuroplasticity can be found here:

http://www.ncbi.nlm.nih.gov/pubmed/20346399

"You never know when it will be needed":

http://www.cq2k.com/about_morse_code/Medical_Uses_of_Morse_code.htm

Why is morse code still in use? We know it is technically efficient, is good for the brain, but many people use morse because it's really fun!


-1

Morse Code needs to be known as it is the lowest common denominator for emergency situations.

I am aware that there are radio installations for use in emergencies in nuclear fallout situations and the most likely signal to get through will be morse [although whether it's detectable over any background radiation is another question].


10

Because it's fun to send and receive messages by Morse code!

It's something that can be done without any specialized equipment for sending and receiving. It's a shared historic experience. It's a challenge, and a skill that is fun to learn. It puts you into a special "club," setting you apart from those non-CW capable hams.

But mostly, it's just fun.


9

I love Morse code for these reasons:

  1. It's fun.
  2. There is something satisfying about pulling a really weak signal out from the noise just 10s of Hz away from another really strong semi-local signal, and making a decent contact with someone halfway around the planet with less than 100W.
  3. I can put headphones on and operate in the living room while the XYL is watching TV (think: condo in the city), and neither of us is disturbed by the other. I'm busy calling CQ DX (from here in Thailand you can get quite a lot of responses when the conditions are right) while she's watching some awful soap on TV - and we're both happy!
  4. Speaking of condos in the city - with a compromised antenna and reduced power, you can STILL work the world with a little help from the propagation gnomes if you use Morse code.

Reason 1 is the main one though :)


7

It was all I could afford when I was a kid. AM and SSB gear was expensive and still is! Stuck with it because: Signals are stronger, More of a challenge, and a CQ gets answered faster. Great people on CW.


-2

Using Morse code is a skill, and people like to practice their skills.