DIGITAL MODES :

Discussion in 'Survey Center' started by M0XRZ, Nov 30, 2018.

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  1. AA5CT

    AA5CT Ham Member QRZ Page

    You're probably right in a technical sense; the logic of decoding such digital modes could probably be done on one of today's FPGA's/CPLDs, given the right algorithmic solution(s) programmed into such a device.
     
  2. K8JD

    K8JD Ham Member QRZ Page

    You beat me to this one !
    Yes CW. Some hams use a computer for Morse but they are not REAL CW ops ! (they are digital contesters usually)
     
    K8PG likes this.
  3. K8JD

    K8JD Ham Member QRZ Page

    YES they Do, it is incorperated into the radio, a Large scale chip with the algorythm for encode and decode the voice into digi format. along with support circuitry...A COMPUTER in the radio !
    Remember when mobile phones were just fancy radios, now the smartphone is mostly computer ! Today there is DRM on short wave broadcast bands, Digital, FM quality, Audio on short wave ! It needs a computer with the software to decode it. If this mode ever really takes off, you will see radios made with the decoder built into them ...A computer in the radio.
    I have seen this idea, computer in the radio, for over 30 years, coming in the commercial two way radio field, with first, Trunked and then digital modes. A large portion of the radios were computer circuits to find a home channel code or look for a group ID, and manage a lot of other programming! Along with short precanned text messages you send with the push of a button.
     
    Last edited: May 3, 2019
  4. W4EAE

    W4EAE Subscriber QRZ Page

    If this is the road you want to go down, I think that you could go even farther. Pedants are free to argue, but transistor-transistor logic has been around for nearly sixty years. This is 'computing,' all be it simple. Go to the National Museum of Computing adjacent to Beltchley Park. The Colossus is covered in valves. The Lorenz machine is entirely mechanical, but it is 'computing.' Transmissions of information encoded on the Lorenz machine were computer aided transmissions. Computing has been part of radio for longer than all but a few of the people on this forum have been alive.

    It would be extremely difficult--if not out right impossible--to find a commercially produced transceiver that you could say does not contain a 'computer' in any fashion. I'll bet that you could not find a simple coffee maker that did not contain a 'computer.' Is this a bad thing? Part of the justification for our licenses is to contribute to the advancement of radio art. If we all do the exact same thing Amateurs were doing 60 years ago, are we meeting that expectation?

    My original statement is to answer all of the statements like:

    'You have to have a computer to program a DMR radio.'
    or
    'To talk to anyone on DMR, you have to use the internet.'

    These statements are false, but ubiquitous. To satisfy the pedants, I will amend my statement:

    DMR, C4FM, and D-Star do not require a separate computer, or the use of the internet.
     
  5. WD0BCT

    WD0BCT Premium Subscriber QRZ Page

    Analog computers have been around much longer than digital. Programing on an analog computer requires modifying components. Programing a digital computer requires modifying software.
    I think when most people think of a computer today they think of the digital software modifiable variety.
     
  6. W4EAE

    W4EAE Subscriber QRZ Page

    When I really think about it, I have a lot trouble finding the absolute dividing line between 'analogue' and 'digital.' With an audio waveform, it is straightforward enough: 'analogue' is a continuous wave and PCM 'digital' is a series of steps. When it comes to analogue vs digital computers, that is where it get murky. When we refer to analogue and digital computers, we are not talking about what the machine actually does; we are talking about how we interface with it. Even when we make modifications in software, we are making changes to the physical characteristics of components in the system; just at a microscopic level. 'Software' and 'code' are stored and accessed by means of physical representation.

    Maybe the line exists not where the systems fundamentally changed, but rather when they got down to certain physical size.:)
     
  7. WD0BCT

    WD0BCT Premium Subscriber QRZ Page

    Not murky at all. Back in my early days of engineering we had power system analysis computers. They would simulate a transmission and distribution system consisting of Generators, step up transformers, transmission lines, transmission transformers, distribution system transformers and distribution lines serving known loads. An analogue computer used actual L, C, R componentents, transformer and simulated loads of various wattages and PF. They would model specific utilities and pass actual 60hz voltages to see the effects upon of generator exciters, tap changes, or line drop outs due to protective relaying . Both GE and Westinghouse built these system simulators and ran test cases for utilities. They were referred to as analogue models.

    When digital computers came along they found the large bulk analogue models were no longer necesaary and models could be created with software. Any murkiness might appear when a hybrid model is created. Then some interfaces might occur requiring DAC. Any system processing audio would fall into this category. The end product interfaces with the human ear...which to date is an analogue process.
     
  8. W4EAE

    W4EAE Subscriber QRZ Page

    This does not conflict with my larger point. The big change is in size and how we interface with it. These bulky components still exist in the software, both conceptually and physically. You could argue that only representations of them are in the software, but that would lead to having to make other assertions such as 'The written word is not language.'

    I simply take the view that in the future, this line we see so clearly now will have disappeared.
     
  9. AA5CT

    AA5CT Ham Member QRZ Page


    Mini-grid, complete with mini-gens (this sort of thing is not dead yet):



    And - synchronizing gens:

     

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