Telegraph

goldenwonder

does anyone use telegraphs anymore as a hobby?
can anyone even use morse code.
was thinking of building a wireless telegraph but it'd be kinda pointless if noboday could here.
i was intruiged by movies as they are on of the most basic communications but still quite effective.

watty

Lots of people use Wireless Telegraphy.

And that uses Morse code.

You can use top and bottom wire of a fence to carry the signal. Early telegraph use what Radio folk call a "straight key". The press connects battery or power to the wire and the other end just has a small soliniod. There is no tone. Even on Radio the tone is artificially created in the receiver. The Sending key (transmitter) simply turns a continuous wave (CW) on and releasing the key stops it.

So CW on the Radio (wireless telegraphy) is identical to morse code over a pair of wires.


You can make or buy a "straight key" today.

Some times you see only one wire in the old pictures. They used high voltage and the return wire was a big earth spike. Not as reliable as two wires and needs dangerous voltage for any great distance.

A lot of Radio and phone "txt spk" abbreviations date to the Victorian Telegraph era. As does spam!

A nickname for a poor operator is a "lid".
One story is that the receiver would be rested against a tin lid as the dots and dashes (dit, dah) can be hard to distinguish with just clicks. On receive the start and end of dot or dash are both clicks, but the key down click is slightly different to key up click (start of "silence", end of the dot (dit) or dash (dah)

Another receiver technique was to start a constant speed paper tape and the receiver coil moved a pen or pencil. This was used with wired and radio telegraph and created a permanent record. Also easier to interpret on early radio systems with fading as the change in line position is clearer than "clicks".


Have you read "Discworld" books? The Clacks.

Europe had Clacks for real! Semaphore arms by day and lamps and shutter by night. Optical Telegraph. It's about a hundred years older than wired Telegraph with Morse Code (Modern Morse code differs slightly from US railroad telegraph code). It can even be faster than Morse code!
http://en.wikipedia.org/wiki/Semaphore_line

If you wanted security you used a code. Wired Telegraph wasn't any more secure than Optical. Wikipedia erroneously claims Electric Telegraph was more private. It wasn't. A wide variety of codes used in optical and electrical telegraph eras. The Famous WWII "Enigma" machine for code was invented before WWII for use on wired telegraph. Lorentz was even more secure system and theoretically unbreakable if implemented used properly. In practice the actual Lorentz machines had a fatal flaw accentuated by operators breaking the rules (never send the same message twice and never send two different messages with same key on Lorentz).



also http://en.wikipedia.org/wiki/Telegraph

http://en.wikipedia.org/wiki/Heliograph

goldenwonder

that was alot more info than i was expecting in such a short time.
thanks Watty.
think i might go ahead and make a key so. ive seen a good few online plans and builds.
cheers

goldenwonder

watty you know your stuff.
maybe il just buy the key for now. no point leaving room for error at the beginning.
and i guess i should learn to use morse code more fluently.
is it true that you can use an am radio on a blank station to receive?
i would have thought it to be on a more specific frequency but thats what the internet has told me so far.
any idea of the distance a wireless can go,
i know thats probably like saying how longs a piece of string but any plans ive seen using a few d cell batteries and a lengthy wire as antenna fail to mention its range
i know from experience with CB, the range is usually alot less than what youd optimistically expect

FarmerGreen

>>Some times you see only one wire in the old pictures.
Watty, I seem to remember that the resistance from one earthing system to another anywhere on the planet is only a few hundred ohms.
I'm pretty sure I'm not making it up.
Its quite astounding isn't it?

watty

Re: one wire + earth:
No. it's 1000s, 10,000s or Millions of ohms and varies with distance and terrain.



You can't transmit without a licence.

Practice with an Audio beeper and key (even the beep on a multimeter tester). Get a friend enthused too and then you can use two beepers and two keys connected by two wires (all in parallel) and you will hear your own or the other key down.

Molloys Clondalkin

If you have an ndroid phone theres a few great programes on the market for morse.
It used to be a full time thing for me just recieving things from hams on 7-7-7100 to numbers stations etc.

I love it and Ive notiiced its picked up a little since the early 00's

watty

Plenty of PC free programs too.
Also symbian and iOS