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Is Ham Radio Different Than "in the good ole days?"

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  • PHIL WESTOVER
    A Quick Note from Phil, WA7URV: I came across the following interchange between two hams who were discussing elements of the new Elecraft K3. Upon reading it,
    Message 1 of 2 , Jan 29, 2008

      A Quick Note from Phil, WA7URV:

      I came across the following interchange between two hams who were discussing elements of the new Elecraft K3.  Upon reading it, I thought about what hams discussed when I first got into amateur radio in 1972.  I don't think the discussion in 1972 went like this:

      Original Comment by a Ham Radio Operator:

      “The DSP filters and DSP modems following the IF filters cannot re-constitute the "distorted" signal so...”

      Response from another Ham Radio Operator:

      “Do not, rather than cannot.

      Firstly, the Finite Impulse Response (FIR) filters used need not, and are almost certainly constructed so that they do not, introduce any group delay distortion of their own. That means that you can still use narrow DSP filters, even if you have to compromise the roofing filter.

      Moreover, it has been standard practice for at least a couple of decades, to use adaptive versions of such filters to mitigate group delay distortion in telephone modems. In that context, they generally require synchonrous transmission, because the standard adaptive equalizers only fully cancel inter-symbol interference at the actual sampling points. Although synchronous operation does make the adaptive process easier, I'm not sure that the longer filters that can be implemented in modern fast DSPs.  Combined with the relatively fixed distortion in the receive filters, they cannot compensate for non-synchronous signals.”

      Is Ham Radio different then it was  “in the good ole days?”

    • Wes Hayward
      Hi Phil, Well, very interesting. I forwarded this to Roger, my younger son. Roger, ka7exm, as you might recall worked in the DSP area for quite a while.
      Message 2 of 2 , Jan 30, 2008
        Hi Phil,
         
        Well, very interesting.   I forwarded this to Roger, my younger son.  Roger, ka7exm, as you might recall worked in the DSP area for quite a while.    I have never done any DSP work, but have certainly done a lot of filter work in both the ham and the professional arena.   I also put together Bob Larkin's stuff on DSP for the book.   Anyway, Roger commented, "This DSP stuff is just some guy trying to shoot out a bunch of buzz words.  What good does a garbage discussion like this do for anyone?"    He confirmed my feeling.
         
        I'm seeing this sort of thing in amateur radio though.   For example, you often see a QST paper where the the author is listed as having a PhD.   I get email letters from folks where they list their credentials.   I hate this stuff and worked hard to avoid telling anyone what I did for a living.    I didn't hide that I worked for Tek or TQS, but didn't list degrees or any of that stuff.   It was good enough for me to just say "Wes has been doing this since God was a pup."  I had to bend when we did EMRFD, for the book was aimed partially at the crossover professional community and folks wanted to know how I fit in.   But it has never been in QST.    Perhaps if it was detailed, the papers would be better accepted?
         
        But that "show off" attitude among a few of the professionals is just a small part of it all.   These folks are clearly doing nothing good for amateur radio.    Indeed, I feel that they are doing it a great disservice.    The more common situation is the opposite one where you have the folks who are not up on much of any technical ideas and complain about amateur radio being too technical and that it should not be that way, for they are, after all the common man and the grass roots.   "So dumb it down for us regular folk."  And so on. 
         
        I think that amateur radio is certainly much different than it was in earlier times.   Technical competence is lower than it was, for it is not needed.   The fellow I just quoted who seeks further down-dumbing (that's a weird expression) is correct.   The equipment is much much better and much cheaper.   The bottom of the line transceiver out there these days is still filled with DSP and DDS.     It is all solid state with 100 W out on all HF bands and has wonderful general performance.    Yet a guy can buy one, with power supply and enough wire and coax to put up a reasonable antenna for under $1K.      
         
        My friend Rick commented that the novice of 1960 had greater technical competence than the extra class license of today.    I think he is right.  
         
        There is more to it than just competence.    There is a feeling of things being vital.   The kid who got on the air back then went to a club meeting and was applauded by the other folks in the club and recognized as a member in the best sense of the word.    Not so much today, I suspect.   But then it's been a long time since I've encountered a kid in amateur radio circles.
         
        Well, I don't want to rant and rave like an old timer complaining about how things are not like the good ole days.  Things have clearly changed, and well they should.    The harder question to ask is "Is the change that has happened a good thing?"     The ham interests have been replaced by other things.    The kids of today are programming computers and are building robots.   I suspect it is all OK.  The world no longer really needs amateur radio.
         
        I personally miss amateur radio as the viable thing that it was at one time.   I am sorry that I no longer have young high school kids knocking on the door asking about the antennas.   I'm sorry that I no longer get letters from such kids, as I did for many years.   I'm disappointed that the retirement activity that I had planned on for so many years is no longer possible, now that I'm actually retired.    I used to think that it would be great to be able to get on the air during the week just so I could avoid the QRM.   But now I have to wait until the weekends to find enough folks on the air so I can make a contact.    Finally, am sad about my ability to contribute.   The last thing I ever expected was to find that when I published a paper in the amateur literature, nobody would care about that information.
         
        It's probably best if you don't forward my thoughts.    They would most certainly insult someone.   But thanks for the thought provoking question.
         
        73, Wes
        w7zoi
         
         



         
        On 1/29/08, PHIL WESTOVER <492commish@...> wrote:

        A Quick Note from Phil, WA7URV:

        I came across the following interchange between two hams who were discussing elements of the new Elecraft K3.  Upon reading it, I thought about what hams discussed when I first got into amateur radio in 1972.  I don't think the discussion in 1972 went like this:

        Original Comment by a Ham Radio Operator:

        "The DSP filters and DSP modems following the IF filters cannot re-constitute the "distorted" signal so..."

        Response from another Ham Radio Operator:

        "Do not, rather than cannot.

        Firstly, the Finite Impulse Response (FIR) filters used need not, and are almost certainly constructed so that they do not, introduce any group delay distortion of their own. That means that you can still use narrow DSP filters, even if you have to compromise the roofing filter.

        Moreover, it has been standard practice for at least a couple of decades, to use adaptive versions of such filters to mitigate group delay distortion in telephone modems. In that context, they generally require synchonrous transmission, because the standard adaptive equalizers only fully cancel inter-symbol interference at the actual sampling points. Although synchronous operation does make the adaptive process easier, I'm not sure that the longer filters that can be implemented in modern fast DSPs.  Combined with the relatively fixed distortion in the receive filters, they cannot compensate for non-synchronous signals."

        Is Ham Radio different then it was  "in the good ole days?"


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