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 ... LOOK !!! RICHTSTRAHL-ANTENNEN-PEILKARTE / BERLIN !!! Have a look at the WWII US Army Telegraph Set TG-5-B ... impressum: *************************************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann * 05/05/14 |