TZUTC: -0500   
   MSGID: 462.fidonet-ls_arrl@1:2320/33 28cc3b51   
   PID: Synchronet 3.20a-Win32 master/4985797d2 May  9 2023 MSC 1929   
   TID: SBBSecho 3.20-Win32 master/4985797d2 May  9 2023 MSC 1929   
   BBSID: TBOLT   
   CHRS: ASCII 1   
   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 (1:2320/33)   
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