Telegraph and radio Morse code

Discussion in 'General Electronics Chat' started by PRS, Jan 13, 2009.

  1. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
    989
    35
    Just what is the difference between the Morse Code telegraph of 1860 and that of 1912? How did Thomas Edison identify a dot or dash vs how someone on the Titanic identified the same, using a beat frequency thing that gave him a positive duration of the keying?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    The telegraph keys probably weren't all that different. They both just opened and closed a contact.

    In 1912, radio was transmitted by spark gap. Lee deForest didn't invent the triode tube until somewhat later (1919?), and oscillators came along a bit after that. CW Morse had to wait until the 1920's. Beat frequencies had to wait for superheterodyne receivers. A 1912 Morse transmission was received by something close to a crystal radio.

    Edison noted the so-called Edison effect of vacuum tube rectification, but hadn't the background to see possibilities.
     
  3. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    The sound is different between the two, but here's the thing. In the old telegraph, which was little more than a relay, you could here the engagement of the ?armature? from the coil, and the disengagement. A dit does have a different sound that a dash, but it would be hard to describe verbally. The familiar dit and dah we are used to from oscillators and RF are a bit more distinct and easier to discribe.

    In either case where you learn morse and use it isn't something you think about. The ear hears an "a" and you write an "a". If you had to think about it you could never keep up. Back when I was getting my amature license I got up to 5 WPM, which is pretty pathetic, but it got the point across. Keying a paddle is pretty much the same, you see a letter and muscle memory does the rest.
     
  4. flat5

    Active Member

    Nov 13, 2008
    403
    17
    I don't know about dates - I have not looked it up - I'm VERY tired :)

    The first telegraph system was just clicks - no dahs - just short clicks. The timing was everything. C in morse is _._. In the earlier system C was .. . I believe.
     
  5. davebee

    Well-Known Member

    Oct 22, 2008
    539
    46
  6. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,348
  7. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
    989
    35
    Seems to me it was a matter of watching the the mechanism that created the tap and interpreting a dot as a quick tap and a dash as a longer tap with an even longer interval between characters. If my memory is right, Thomas Edison was said to have done 70 characters per minute -- and he was deaf in one ear!
     
  8. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
    989
    35
    You must be right. After all, it worked even before oscillator-made sound was added.

    Thanks. I'm going to learn Morse Code and become a Ham. :)
     
  9. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
    989
    35
    Seems to me that a beat frequency oscillator just made it easier and perhaps more clear to the operators, but was only an improvement upon a system that was workable in the first place.
     
  10. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
    989
    35
    Great links! Thanks! Isn't it amazing how people can think their way through problems that seem insurmountable at first? If I ever get to vacation on the east coast I'll make a point of seeing the museum you refered us to.
     
  11. subtech

    Senior Member

    Nov 21, 2006
    123
    4
    You may want to try a google search for "railroad telegraphy" and "telegraph sounder"
    for some more info on the differences between the first code and what we use today.
    If you are starting to learn the code, remember just a few very important points.

    Morse code is a language. Letters and then words are combinations of long and short sounds.

    Morse is NEVER visual. Don't EVER look at printed charts showing the dots and dashes. If you learn that way, you will have to convert sounds to mental pictures of dots and dashes in order to get the letters, and later on words. Your speed will be greatly impaired.

    Focus on the sounds, and practice every day for a few minutes at a time. When you know a few letters, you will be able to put together words. Hum or sing tones to create your words. The more you use the code, the quicker it will come to you.

    Here is a great resource: http://www.fists.org/

    Something worked for and earned is a treasure. I hope to hear you on the air!

    Mike
    N0RTU
    I'm proud to be a KNOW CODE ham.
     
  12. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
    989
    35
    I especially thank you for the link to FISTS. It sounds like I'm going to learn my ABCs all over again! Thanks for the advise. I've checked out the ARRL manual for getting a license and I think I'm just about ready to get the beginner license. As for the 5 wpm Morse Code test, I'll do that a bit later. Thanks again. :)
     
  13. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    2,040
    287
    I can still bop along at about 45 wpm on a good day. :)

    By the way the Railroad code (also known as "American Morse" had a few different characters than International Morse. There were actually two different "dashes" a long one and a short one. T was the short dash and L was the long one. Also the landlinese used CLICKERS instead of tones and buzzes....INFINITELY more difficult to copy. I thought I was fairly proficient at CW until I tried copying MORSE with a landline sounder! YIKES...those old buzzards were GOOD!


    By the way, you HAVE to see this You Tube! :)


    http://www.youtube.com/watch?v=AhsSgcsTMd4
     
  14. PRS

    Thread Starter Well-Known Member

    Aug 24, 2008
    989
    35
    45 words per minute, not just characters? That's fast! I can only type about 60 words per minute.

    Here's another question I have that I'm sure you can answer: The dot gets, say, a unit of time; the dash gets 2 units? What about the space between characters? I should think spaces are important; otherwise a person could get lost.

    As for your link to the video, I tried it, but my computer runs to slow to watch it. Thanks anyway! :)
     
  15. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    2,040
    287

    The dash is three units, the space between symbols is one unit. Space between letters is 2 units, unless your from the South, in which case it's between 3-5 units. (Yes, there is a Southern Drawl on morse code!)

    Eric
     
  16. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,176
    397
    By all means follow subtech's advice on not learning from printed charts,the Boy Scouts manual with thier charts ruiend my code attempts,also typing is a must, one more of my failings, but i'm going to restart any day now,I just turned 82 today, lots of time yet.
     
  17. flat5

    Active Member

    Nov 13, 2008
    403
    17
    Happy Birthday to you with your wonderful attitude!
     
Loading...