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Author Topic: I wonder about morse code  (Read 20852 times)
W4KYR
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« Reply #15 on: January 08, 2018, 07:44:07 AM »

The telegraph with sounders used American or 'land line' Morse, which had significant differences from International Morse Code. For example, a 'P' was 5 dots....so a very good test of using a mechanical bug key was to be able to send 'Mississippi ships' in American Morse.

You may wonder why mechanical Morse keys in the US have a 'switch' to short circuit them. This is because in the land line system, all keys and sounders were in series, so if a key was left open, there was no communication possible. Not necessary for radio purposes, but while the railroads were using Morse, there was a demand for keys of that sort. Can be useful when tuning a tx, though.

I wonder how they could send code vast distances in the 1860's before the advent of amplifiers.
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The internet and cellphone networks are great until they go down, what then? Find out here. 
https://www.eham.net/ehamforum/smf/index.php/topic,111948.0.html

Using Windows 98 For Packet...
N8YX
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« Reply #16 on: January 08, 2018, 09:38:20 AM »

...I wonder how they could send code vast distances in the 1860's before the advent of amplifiers.
By means of lots and lots of wire.  Grin
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N9LCD
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« Reply #17 on: January 09, 2018, 07:41:00 AM »

I think they used one of two methods: higher voltage on the .line to overcome line loss; or "relay" when the message had to be resent after X miles.

Also, I heard of something called a "magnetic amplifier" in connection with the telephone system before the advent of vacuum tubes.  Never found anything on this gear.
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G3RZP
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« Reply #18 on: January 10, 2018, 09:23:04 AM »

Magnetic amplifiers for telephones probably worked on a similar basis to the way magnetic amplifiers in servo systems worked.

If you used sensitive relays, you could send code over very long distances. The first Transatlantic telegraph cable (laid in 1865 by Daniel, who became Sir Daniel Gooch for doing it, using Brunel's ship the Great Eastern) suffered with speed problems because of the inductance and capacitance of the cable. When they tried speeding things up by using more volts, they punctured the insulation....
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VK6HP
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« Reply #19 on: January 12, 2018, 05:07:22 AM »

The foundations of transmission line theory are encapsulated in the "Telegrapher's Equations" developed largely by Oliver Heaviside in the late 19th century.  They flow from the relation of the rate of change of voltage and current along the line to the elemental (infinitesimal) equivalent circuit, involving series and shunt elements (R, L, G, C).   The solution of the equations gives important quantities such as propagation velocity and what we now call characteristic impedance.  But the big insight of the day was how to minimize distortion of keying pulses, since long cables such as those across the Atlantic suffered terrible pulse dispersion, which severely limited the keying speed.  Turns out that if the "Heaviside Condition", where G/C=R/L, is satisfied the line is distortionless (but not lossless).  The only practical way of approximately meeting the Condition was to increase L, by periodically "loading" the line, a practice that continued for decades.   

73, Peter.
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KC8KTN
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« Reply #20 on: January 12, 2018, 09:59:21 AM »

WOW. Awesome information THANKS TO ALL.

Have a Blessed Day. Be Safe , GOD BLESS.

.............END OF TRANSMISSION.........................





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KA4DPO
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« Reply #21 on: January 12, 2018, 11:24:12 AM »

I think they used one of two methods: higher voltage on the .line to overcome line loss; or "relay" when the message had to be resent after X miles.

Also, I heard of something called a "magnetic amplifier" in connection with the telephone system before the advent of vacuum tubes.  Never found anything on this gear.

Samuel Morse invented a telegraph repeater sometime in the 1850's and a guy by the name of Milliken, developed a vastly improved repeater in 1864 that enabled transcontinental telegraph without relay operators to forward messages.  It was a very sensitive relay that employed a high power battery bank at each repeater site so that the original signal was amplified on the line. 
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G3RZP
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« Reply #22 on: January 12, 2018, 02:47:58 PM »

Even more miraculous was transatlantic Speech. In 1927, it cost $27 A MINUTE - and $27 then was worth a hell of a lot more than now!
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KC8KTN
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« Reply #23 on: January 15, 2018, 07:56:25 AM »

I wonder back in the days of telegraph if individuals tapped into the telegraph lines to listen what was going on..

https://www.pri.org/stories/2013-11-07/history-electronic-surveillance-abraham-lincolns-wiretaps-operation-shamrock

Have A Most Joyous Day.. Be Safe...... God Bless.............

............................END OF TRANSMISSION..............................

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N0YXB
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« Reply #24 on: January 15, 2018, 08:15:14 AM »

The answer is yes. Interesting topic.

https://motherboard.vice.com/en_us/article/xy9v7z/wiretapping-is-as-american-as-apple-pie
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WZ7U
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« Reply #25 on: January 15, 2018, 10:40:45 AM »

Hence the concept of wiretapping.
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AA4HA
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Posts: 2630




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« Reply #26 on: January 27, 2018, 07:34:08 PM »

A magnetic amplifier for wired telegraphy can be something as simple as a sensitive relay driving a set of heavy duty high voltage DC contacts to "repeat" the low level incoming CW on/off to a signal that would be able to get to the next distant point.

Maybe you put one of these boxes with a relay and a battery every 10-15 miles. Then it is all automatic
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Ms. Tisha Hayes, AA4HA
Lookout Mountain, Alabama
W9FIB
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« Reply #27 on: January 28, 2018, 01:06:21 PM »

Nice little article here.

http://w1tp.com/pertel.htm
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73, Stan
Wisdom is knowledge you gain after you know it all.
KC8Y
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« Reply #28 on: January 28, 2018, 01:57:29 PM »

I love the article Smiley , by w1tp

Ken KC8Y
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KL7CW
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Posts: 555




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« Reply #29 on: January 28, 2018, 07:25:16 PM »

About 10 years ago I bid on lots of very old telegraph sounders on e bay and ended up buying about 10 of them eventually.  All of them worked just fine, most were NOT in mint condition, but not bent or rusty (dirty is OK).  A 4 ohm sounder hooked in series with a key and 1.5 volt D cell will give you many hours of clicks and clacks.  Higher R sounders require higher voltages.  I built a converter to convert off the air tone Morse code, the kind we use on the ham bands, to a DC voltage.  It worked great, and I immediately could copy the sounder clicks and clacks nearly 100 percent at perhaps 18 WPM (I had never listened to sounders before) and got my 15WPM ARRL certificate easily with only about 2 or 3 hours practice.  Now I have been a ham CW op since 1954 and also some commercial ship and shore work I am sure helped.  To me the clicks and clacks were very easy to read and I am sure I could get solid copy at > 30 WPM with a little practice.  My average cost of a sounder was perhaps $50 and I had many hours of fun with them.  If you can bid on something like say a 15 ohm to perhaps a 150 ohm sounder, these are convenient sounders to build converters for, however lower and higher resistance sounders will also not be too difficult to design for.  Some of the old Western Union sounders on black wood bases come up for low prices since the black wood base paint peels off and the metal parts tarnish, but they sound as good as some of my shiny new looking purchases.  Neither sounder code nor American Morse code (the code used by the W U and railroads for over 100 years) are any more difficult to learn, copy, or send than our ham International Morse code.  In fact American Morse code is slightly more efficient than "our ham" code. The American Morse code worked just fine on landlines but did not work well on the radio circuits.  It has short and long dashes and some letters have strange spaces within a single letter, example C   is   dot dot small space dot.   Ok for wire circuits, but not for radio circuits with static, QRN, and QRM.  Several times through the years I started to learn American Morse....it seemed natural and easy...but never followed through with enough practice.  Go to the "Morse Telegraph Club" website for a wealth of info on Sounders, American Morse, circuit diagrams, magazine subscription, etc.
         Rick   KL7CW    Have fun with an old sounder and key.......I had a blast....perhaps the most fun since my first QSO in 1954
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