Is CW a true, pure digital mode?

Discussion in 'Working Different Modes' started by KC0BUS, Apr 2, 2019.

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  1. AC0GT

    AC0GT Ham Member QRZ Page

    No.
     
    KQ0J likes this.
  2. W5DXP

    W5DXP Ham Member QRZ Page

    There are two definitions of "digital" in The IEEE Dictionary.

    1. Is CW analog? If not, it is digital.

    2. Is CW discrete? If so, it is digital.

    Single tone on/off meets both definitions.
     
    K4AGO and W1TRY like this.
  3. N8AFT

    N8AFT Subscriber QRZ Page

    THANK YOU!
     
    W1TRY likes this.
  4. KF5LJW

    KF5LJW Ham Member QRZ Page

    Finally someone who knows something. Not only is CW digital, it is encrypted.
     
  5. SM0AOM

    SM0AOM Ham Member QRZ Page

    Morse or "CW" becomes "encrypted" only if the source text is run through a
    crypto device such an Enigma or Hagelin before transmission.

    If "no-coders" cannot read a plain-text Morse message, it is their loss.

    73/
    Karl-Arne
    SM0AOM
     
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  6. K0RGR

    K0RGR Premium Subscriber QRZ Page

    Hellschreiber is another mode that uses CW - not human readable telegraphy.

    Besides which, computers do CW very well within certain limits. There are lot of no-coders who work DX in contests using computers. Most of the DX stations in a contest these days will be using some sort of computer to send, and computers can copy computer generated CW very well, and generate a proper CW response.
     
  7. N2SUB

    N2SUB Premium Subscriber QRZ Page

    You could make a case either way, but CW is binary (on/off = 1/0), and by definition binary is digital. Your computer decodes FSK as a series of 1s and 0s. So you could say by that definition, CW is a digital. I call CW a mode because when I hit the MODE button on my rig, CW is one of the options. My logging program has it as a mode, and so does every award I can think of, so there seems to be a consensus.

    On the other hand, since you send CW with your digits, it most certainly is a digital mode. :)
     
    W0AEW and K4AGO like this.
  8. SM0AOM

    SM0AOM Ham Member QRZ Page

    Hellschreiber is "CW" in the sense that an undamped carrier oscillation is modulated by on/off keying, but it actually belongs to the "facsimile" or "picture transmission" category, with the proper designator of A1C (or J2C if the generating method is a keyed audio sub-carrier).

    73/
    Karl-Arne
    SM0AOM
     
  9. KC9YGN

    KC9YGN Platinum Subscriber Platinum Subscriber QRZ Page

    The answer is a resounding maybe?

    To be pedantic to the point of ridiculousness, no. The term "digital" in the communications sense means the use of a computer to encode/decode information to and from human understandable communications into a form that is machine readable only. CW can be done by computer, but it can be used directly by human beings and does not require the use of a computer. So it is not "digital" in that sense that a computer is required.

    Some believe it is a form of binary encoding, the way data is stored in computer memory in patterns of bits that are set to either a 0 or 1. They claim that because of this on/off state it is somehow 'digital'. That isn't true either. Yes, CW is either on or off when sending, but it adds an additional parameter, time, which is necessary for determining whether a pulse is a dit or a dah. Binary data has no such time requirement. It is either an on or off state, no timing element is necessary. So therefore it is not a true binary encoding either.

    In the real world? I really don't care what we call it and ultimately it doesn't matter. The definitions of words change all the time to suit the needs of the culture that uses them. If people want to call CW "digital" it's fine by me because when it comes right down to it, what matters is the meaning people give to a word.

    Heck, one could argue that the term "digital" means something relating to a finger or fingers, and since CW is sent with a keying device of some kind operated by one's fingers, then, yes, it is indeed "digital".
     
    K4AGO likes this.
  10. AC0GT

    AC0GT Ham Member QRZ Page

    Binary data has no time element but a binary data stream does.

    This time element is defined with some precision or the communication fails. This is often where computer decoding of hand sent Morse code often fails. I saw some demonstrations of early Morse code decoding software and failure was common unless there was a previously agreed upon speed for it to be sent. This meant the CW had to be sent by computer or a person with very good timing.

    Modern Morse code decoding is considerably more accurate than before because computers are fast enough that they can put some logic into the decoding to pick out common phrases, basically "spell checking" the stream of dits and dahs.

    There's some digital protocols that include the time element (or clock) with the data which can make this time element simple to determine. I don't know of any such protocols that go over the radio, but many such protocols exist for over a wire. Morse code and CW have no such time element except with enough of a stream history to measure this out, which is probably what the computers do now to decode hand sent Morse.

    For CW to be considered "digital", in anything but the most pedantic sense, there must be a time element defined. This means defining precisely the length of a dit vs. a dah, the time between letters and words, etc. Do that and perhaps you have a digital mode.
     
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