• Ham Radio History (C)

    From Daryl Stout@954:895/7 to All on Friday, May 19, 2023 00:05:08
    SOS

    The amateur distress call, QRRR, grew from the purpose of the first
    organized amateur emergency nets. They were set up in cities along the Pennsylvania Railroad to aid the "Pennsy" (and later other railroads)
    with train communications in the event of failure of the railroad
    telegraph landlines--which were frequent. The signal QRR came to be used
    to indicate that the calling station had railroad traffic related to
    some emergency. ARRL eventually adopted this call for use by any amateur
    who had distress traffic and later the call was changed to QRRR because
    of a conflict in definitions with the international Q signal QRR.

    One of the first distress calls was CQD, coined by the Marconi Company
    about 1904 from the "general call" CQ and the letter D for "distress."
    The main problem with CQD was that it was supposed to be used only by
    ships which subscribed to the Marconi radio system and ships of one
    system were discouraged from communicating with ships or shore stations
    of other, competing, companies. The problem got so bad that it was taken
    up in the international radio conference in 1906 where a new universal
    distress call was proposed.

    The American delegation suggested the letters NC which were already
    recognized in the International Signal Code for Visual Signalling. The
    German delegation proposed its own SOE which was already in use on German
    ships as a general inquiry signal similar to CQ (which was then used only
    by the Marconi system). The British delegation, of course, wanted to
    stick to the Marconi signal CQD.

    The convention found SOE acceptable except that the final E could easily
    be lost in QRN so the letter S was substituted, making it SOS. The
    convention decided that SOS should be sent as a single code character
    with a sound unlike any other character, thus arresting the attention of
    anyone hearing it. So was officially adopted, but CQD remained in use for
    some years, particularly aboard British ships.

    It wasn't until 1912, after the Titanic disaster, that SOS became the
    universal choice, and the use of CQD gradually disappeared. Titanic radio operator Jack Phillips sent both CQD and SOS to be sure that there could
    not possibly be any misunderstanding.

    SOS does *NOT* stand for Save Our Ship or Save Our Souls.

    ***

    Mayday

    Incidentally, another distress call is used by aircraft in trouble
    throughout the world. We have all heard the term "mayday" at some time.
    This, of course, has nothing to do with the first day in May. As it
    turns out, in French, the word "m'aidez" means "help me". Is it possible
    that American aviators in World War I picked this up from their French comrades, and mispronounced it as the easily recognized "mayday, mayday"?

    ***

    The Prosigns

    Many of the expressions and procedure signals still in use in
    radiotelegraph had their origins in the early days of the landline telegraph--long before Marconi sent his letter "S" across the Atlantic.

    In sending formal messages by c.w., the first thing a beginner hears is
    "don't send punctuation. Separate the parts of the address from each
    other with the prosign AA." This is ironic, because in the American Morse
    Code the sound didahdidah is a comma, and was doubtless the origin of our prosign. Originally, a correctly addressed letter was punctuated with
    commas following the name and the street address, each of which was
    (and still is) on a separate line although the commas have been dropped,
    even in mail addresses on letters. The comma was transmitted by Morse
    operators and thus, AA came to mean that the receiving operator should
    "drop down one line" when sent after each part of the address, and it is
    so defined in the operating manuals of the time.

    Our familiar prosign SK also had its origin in landline Morse. In the
    Western Union company's "92 code" used even before the American Civil
    War, the number 30 meant "the end. No more." It also meant "good night."
    It so happens that in Landline Morse, 30 is sent didididahdit daaah, the
    zero being a long dash. Run the 30 together and it has the same sound as
    SK.
    --- SBBSecho 3.20-Win32
    * Origin: The Thunderbolt BBS - Little Rock, Arkansas (954:895/7)