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TELEGRAPHY
Have a look at the WWII US Army Telegraph Set TG-5-B ...

A WESTON ELECTRIC TELEGRAPH TEST UNIT FOUND ...
( 163A2  TEST UNIT  J70045B-1 )
w.ZERO-CENTER 25 mA METER,  WE 3C 140 Ω SOUNDER  & WE 1A KEY



A look inside with CABLES IN PLACE ...



Details: LABEL ...  &  the HOLES to hang the unit ...



The WIRE DIAGRAM of the TEST UNIT ...



The +/-25 mA METER is useful in itself ...

The dismounted SOUNDER ...



and the KEY ( mounted on a board ) ...



... MAKES A TELEGRAPH SET ...

BUILD A HISTORICAL TELEGRAPH CONNECTION
**************************************************************************
                           with 2 Sets, 2 Wires and a 4.5 Volt Battery ...

                                 1st Wire
           +-----KEY----->........................>-----KEY-----+
           |                                                    |
        SOUNDER   Main Set                      Remote Set   SOUNDER
           |                     2nd Wire                       |
           +---BATTERY---<........................<-------------+

It is assumed, that one station  ( eg. the remote one )  has the  KEY = ON
with its SHORT-CUT-LEVER to get the message from the other station.

It was discovered that only ONE CUPPER WIRE is sufficient: The EARTH can be
used as the electrical conductor.  And the invention of the 3-POLE-KEY made
the Short-Cut-Lever obsolete: Its rest position is the "Receiving Mode" ...

         

HISTORICAL REMARKS ...
===========================================================================
Before the invention of the  TELEPHONE,  TELEGRAPHY  was the  only possible
high-speed communication  to remote locations. In 1837 SAMUEL F.B.MORSE had
invented a device to sent messages coded in DASHES & DOTS (& SPACES !) to a
receiving device. When the SENDER-KEY is pressed down, the RECEIVER, driven
by an ELECTRO-MAGNET, pushes down a PEN against a STRIP OF MOVING PAPER. In
the same way as the sender key is pressed,  DASHES & DOTS are placed on the
paper-strip and this could be read and decoded to the message sent.

Later the telegraph operators realized, that they could HEAR(!) the message
without using pen & paper - just by its CLICK- & CLACK-SOUNDS:  A "SOUNDER"
became now a simpler receiver,  placed in a RESONATOR to amplify the sound.
( Set the sounder in an open, upright cookie-box to have the same effect !)

R E M A R K :   These  "CLICK / CLACK"  SOUNDS are  D I F F E R E N T  from
the  CW SOUNDS  ( eg. "dit-dit-dit_daa-daa-daa_dit-dit-dit" = SOS )  of the
wireless communications ( eg. by SW-Radio-Amateurs )  we are familiar with:

THE INTERNATIONAL MORSE CODE:
---------------------------------------------------------------------------

A  .-      F  ..-.    K  -.-     P  .--.    U  ..-      1  .----   6  -....
B  -...    G  --.     L  .-..    Q  --.-    V  ...-     2  ..---   7  --...
C  -.-.    H  ....    M  --      R  .-.     W  .--      3  ...--   8  ---..
D  -..     I  ..      N  -.      S  ...     X  -..-     4  ....-   9  ----.
E  .       J  .---    O  ---     T  -       Y  -.--     5  .....   0  -----
                                            Z  --..
T I M I N G :
A DASH is equal to 3 DOTS;  SPACE between parts of same letter  equ. 1 dot;
SPACE between two LETTERS equ. 3 dots;  SPACE between two WORDS equ. 7 dots
Famous TEST-QUESTION to students:    " How much signs has the MORSE CODE ?"
---------------------------------------------------------------------------
The RIGHT ANSWER is:  "MORSE-CODE consist of 3 SIGNS:  DOT, DASH & SPACE !"

Have a Look at my  » MORSE TRAINING SET «,  bought 1956 in Berlin ...

  

... with BUZZER, 3-POLE (WWII-)MORSE KEY ("How cute!")  &  MORSE PRIMER.

             Have a look at the "complete" MORSE ALPHABET ...

My 2nd MORSE-KEY was made 1934 by TELEFUNKEN / Germany ...

    15 cm x 8 cm / 6" x 3_1/8"

  

Enjoy reading about the TELEGRAPH's HISTORY and the people involved  ...

  

Tom Standage / » The Victorian Internet « / Walker     ISBN = 0-8027-1342-4

                  Have a look at the WWII US Army Telegraph Set  TG-5-B ...
impressum:
***************************************************************************
© C.HAMANN        http://public.beuth-hochschule.de/~hamann      * 04/30/14