Subj : Ham Radio History (3) To : All From : Daryl Stout Date : Sun May 26 2019 12:12 am 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 3.07-Win32 * Origin: RadioWxNet: The Thunderbolt BBS tbolt.synchro.net (801:1/2) þ Synchronet þ Temple of Doom BBS - tod.eothnet.com .