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forgotten modes

Discussion in 'Working Different Modes' started by KA1BSZ, Dec 16, 2020.

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  1. K6CLS

    K6CLS Ham Member QRZ Page

    3 wheels? Easy. Built in to linux (rot13).

    4 wheels? I'll get back to you on that..
     
  2. K1APJ

    K1APJ Premium Subscriber QRZ Page

    Me too. Although ARQ mode with a noisy T/R relay would hypnotize you if you weren't careful...

    A pal and I tried AMTOR with a couple Flexradios a while back. Didn't work very well, the latency introduced by the DSP was more than the AMTOR could handle in ARQ. FEC was OK, but why bother with that.
     
  3. W4KYR

    W4KYR Ham Member QRZ Page

  4. AF7TS

    AF7TS Ham Member QRZ Page

    I am going to _strongly_ disagree here.

    What makes something a 'digital' is _not_ binary.

    The key defining feature of 'digital' is quantization of the signal. The signal is transmitted in specific discrete states which can be distinguished even in the presence of noise (to a limit, of course).

    Binary on-off keying is an example of a digital modulation scheme. There are two states, which can be reliably distinguished if the signal is strong enough and the noise low enough. Once you've distinguished between these two states, you could regenerate the original signal with perfect fidelity.

    But quadrature amplitude modulation is also quantized, with far more than two possible signal states per character period. QAM16 has 16 possible signal states, which means that you transmit 4 bits worth of data every signal period. Of course this means that the 'difference' between different discrete states is smaller, less noise is needed to render the signal ambiguous with respect to the actual state transmitted.

    Any quantized signal can be expressed as a number, an since any number can be represented in binary, any digital signal could be described in terms of bits (as I did above describing QAM16 (which is _not_ binary) in terms of bits per signal period.

    By the quantization definition of 'digital modulation', on-off keyed morse is most certainly digital.

    Furthermore, on-off keyed Morse is trivially expressed in a binary representation. Rather than thinking about the different Morse elements ('dit', 'dah', element space, letter space, word space), think about the timing of the signal itself. The basic time element is the 'dit' time, and the signal can be in two states ('on' or 'off). Represent 'on' as 1 and 'off' as 0, with each digit corresponding to a single 'dit' time.

    Using the above 'E' would be written '10' (on for 'dit', off for 'dit'), 'T' would be '1110' (on for 3 'dit' periods, off for 1). HIHI would be '10101010001010001010100010100000' Simple binary representation of on-off keyed Morse.

    The various versions of Morse (OOK, MCW, visible light, audio over FM, etc) are distinguished from most other digital modes in that a human can decode them 'by ear' without computer hardware, and IMHO there should be a special place for human copyable digital modes. But the fact that OOK Morse is human copyable does not make it 'not digital'.

    73
    Jon
    AF7TS
     
    WA9ZZZ and K0UO like this.
  5. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

    Very well stated
     
  6. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

    It may not be your definition and remember 100 years ago you couldn't get a degree in computer technology programming.
    Just because you have a degree and you say CW cannot be a form of digital communication doesn't hold true in its history and use.
    CW is also about timing which is just like counting numbers.
    That's why some of us old Engineers contend that it is a form of digital.
    Many of you guys arguing the fact that's cw is not digital can't copy with your head anyway, and you still have to use a decoding device.
     
    W7UUU and K8PG like this.
  7. K3XR

    K3XR Ham Member QRZ Page

  8. KC3TEC

    KC3TEC Ham Member QRZ Page

    did i say i have to use a decoding device?
    I'll admit my code is a bit rusty and i have to get back up to speed but thats what i get for being away from it for 40 years while working a steady job in a factory!
    and again referring to morse code as cw is a misnomer! and thats where people get confused!
    cw (continuous wave) is not reduced to zero state due to the delayed decay of the oscillating wave! this makes it much more narrow band and an ideal medium to manipulate using morse,
    shorting out the circuit by brief pulsed modulates the wave but never reduces it to zero state.
    a dead key (permanently depressed key) or shorted keying circuit drains the energy of the oscillator reducing it to zero state
    rapidly reducing the wave to zero state makes it very wide band and is classed as electrical interference.

    but a point in favor of your argument morse code itself is a digital format.
    cw is just a medium

    and by the way I am old myself (the first computer i ever worked on in the navy we had to manually punch cards on a special typewriter style machine to program the stupid thing)

    ugh that monster took up a 20 by 40 room and made the hair on the back of your neck raise when you walked within 5 feet of the door!
    ahh the sweet smell of ozone!
     
    Last edited: Dec 18, 2020
  9. KC3TEC

    KC3TEC Ham Member QRZ Page

    and on the note that cw is just a medium
    a carrier wave or continuous wave is used in both am and fm radio broadcast,
    for that matter a carrier wave is still used in almost all forms of radio communications ( Pulsed Laser being the primary exception)
    with am analog or digital signal is superimposed on a carrier wave and the wave is manipulated by amplitude. Fm signal however modulates the frequency of the wave. hence AM Amplitude Modulation and FM Frequency Modulation
     
  10. KA1BSZ

    KA1BSZ Ham Member QRZ Page

    Hay it's me again! KA1BSZ....I would like to invite anyone to use any of these " FORGOTTEN MODES ". I am on 20 meters every morning,every day and I start out with PSK 31 14.070 khz. Should you want to have a qso with me on any mode, please call me on psk31 and simply ask to go to another mode. I can do just about any mode,AMTOR,PACTOR,JT9,CW,RTTY,RTTYM,OLIVIA and even SPARK!!!! Just kidding about SPARK. So any morning from 13:00z on i'll be on PSK 31 AROUND 1300 HZ or so...just call me! I do not care how fast you type or how slow you are, i could care less. if you type 1 word a minute ...so what? who cares! So get on psk and then go to whatever! thank you de ka1bsz.
     

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