Telecommunications

Alexander Graham Bell conceived of the telephone at his summer home in Brantford, Ontario and physically created his first phone in Boston, Massachusetts (where, he said, it was 'born'). This was a result of his research into improving the telegraph system. Bell was experimenting into improving the telegraph system so that multiple messages could be sent at the same time (his theory of the 'harmonic telegraph' was based on the principle that several messages could be sent simultaneously along the same wire if the different telegraph signals each had a different pitch). However at the same time he began working on the novel idea that speech could be transmitted electronically, as he accidentally discovered that the sound of a spring being twanged could be heard over his harmonic telegraph system. Almost a year later in March 1876 Bell uttered the first famous words into the device to his assistant in the next room: "Mr. Watson, come here - I want to see you".

Western Union/Lineman Splice

The Western Union or Lineman splice was developed during the introduction of the telegraph to mechanically terminate aerial conductors that were subject to loading stress. The wrapping pattern is designed to cause the termination to tighten as the conductors pull against each other. This type of splice is more suited to solid, rather than stranded conductors, and is fairly difficult to complete. The termination shall comply with all the requirements of NASA-STD-8739.3 for a solder termination, including the following: a. The conductor ends shall be parallel to, and in contact with, each other.

b. The conductors shall exhibit proper insulation spacing.

c. The wraps shall be tight, with no gaps between adjacent turns. The wraps shall not overlap, and the ends of the wrap shall be trimmed flush prior to soldering to prevent protruding ends.

d. The completed solder termination and any exposed metallization shall be over-sleeved with transparent / translucent heat shrink tubing.

e. The termination shall not be located in a flexure zone and shall be provided acceptable stress relief.

Testing to determine Lineman Splice 22 AWG wire pre-solder condition compared to Lineman Splice 22 AWG wire post-solder condition

In order to determine the reliability of the Lineman Spliced connections pull testing was performed on 5 samples of Lineman Splices with 22 AWG wire compared to the tensile strength of an unspliced piece of 22 AWG wire. The same testing was also performed on 5 samples of Lineman Splices with 16 AWG wire compared to the tensile strength of an unspliced 16 AWG wire. The results are as follows:

� The average tensile strength of the 22AWG wire un-spliced was 20.7 lbs and the average tensile strength of the 16 AWG wire un-spliced was 62.6 lbs. � The average tensile strength of the wire before breakage was 17.7 lbs for the Linman splice using 22 AWG, and 58.9 lbs for the Lineman splice using 16 AWG. (See summary below) � There were no failures at the splice area where the solder connection was made. In every sample the wire broke outside the splice area usually close to the point where the wire was secured to the pull tester.

As one can see the tensile strength of the spliced wire is very close to the tensile strength of the un-spliced wires.

It is thought that the reason the spliced wire did not meet the tensile strength of the un-splice wires is due to the slight offset of the wires at the splice causing an uneven stress where the wires were being held in the pull test fixture.

Conclusion:

In no case was there any failure of the wires at the splice connection. In every splice sample the wire break was outside the splice area. The tensile testing showed that the solder connection at the splice was as strong or stronger than the un- spliced wires and there is no reliability issue associated with this type of splice. Based on this study Lineman Splicing can be a reliable, secure means of splicing wires together.

Wire Gauge Average Tensile strength(Un-spliced Wire) Average Tensile strength (Lap Splice)

22 AWG 20.7 lbs 17.7 lbs

16 AWG 62.6 lbs 58.9 lbs

In international Morse code, K would be written as:

-.-

If you were to say it out loud it would be:

dah-di-dah

If you were to hear it, you would hear a long beep, then a shorter beep and a final long beep.