[CW] PBL

[Richard Knoppow]

     May be OT. I have a copy of Mary Texanna Loomis' book "Radio 
Theory and Operating" 3rd eidition (1927)
http://hamgallery.com/Tribute/W3YA/
  and many other sites found by Google
    Even though I've had it for years and read through it I still 
sometimes discover something new. This time it was the 
explanation of what PBL means. One finds PBL at the head of lists 
of "Q" signals in many books, especially older ones. It is 
sometimes called "Preamble" and is listed as meaning:
As a question "Do you want to communicate with me by the 
International code of signals?" and as a statement "I want to 
communicate with you by the International code of signals."
   So what is that?  Turns out that by International code of 
signals is meant the international system of flag signals. These 
are the things one sometimes sees flying off a halyard on a ship, 
particularly Navy vessels. So, what has this do to with radio? 
Its not obvious but each signal flag is represented by a letter 
of the alphabet or number. So, a series of flags can be written 
as a text message and therefore can be sent in Morse. The 
relevant part is that there is a whole lexicography of flag 
messages, which are the same in all languages of the flag code. 
That is, when a ship flies flags the message is understandable in 
many languages, one looks it up in the flag code book. Well, this 
applies to flag messages sent in Morse as well as visually. So, 
suppose one needs to communicate with a ship where the radio 
operator does not understand your language you can send a message 
via the flag code which he can interpret in just the same way as 
a visual array.
     I don't know to what extent this was practiced but its 
usefulness is obvious. And so we have the mysterious sign PBL 
sitting up there at the head of the Q signals (P comes before Q).
     Many books don't show it but then many books have incomplete 
Q signal lists, particularly ham radio handbooks. Mary Loomis' 
book is the only place I've seen it explained.
     If you look up Mary Texanna Loomis also look up her father, 
Mahlon Loomis, who claimed to have invented wireless well before 
Marconi. I don't think anyone really "invented" wireless and am 
rather skeptical of Loomis claims but both he and his daughter 
are interesting characters in the history of radio.
-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL