Telegraph Equipment

© Brooke Clarke 2006 - 2009

    Ticker Tape
       Western Union 5A Black Box stock quotation printer
        Teletype model 36 Monopulse Printer
        Overview of Teleprinter Model Numbers 
        Table of 5 Level Teletype Code
        Punched Paper Tape - 5, 6, 7, & 8 level
    Telegraphic Fire-Alarm
    Pole Changer
    255A Polar Relay
    17-B Polar Relay
Dial Telegraph
    Binding Post
    Banana Plug
    1/4" Phone Plug
    Fahnestock Clip
    Telegraph Paper Tape & Jacquard Loom
    Gill Selective Telegraph
    Gamewell (new web page)


In 1832 Joseph Henry published an article describing how he made electro-magnets that could support hundreds (maybe thousands) of pounds by wrapping Bell Wire with fabric to insulate the wire from adjacent turns and using many turns on a soft iron core.  At this time Bell Wire was a flexible metal wire without any insulation that was used to connect a pull cord with a small bell, like in a hotel or mansion.  Prior to this there had been a publication showing the uninsulated wires could be wrapped so the did not touch each other or the soft iron and that would magnify the magnetic effect.

Iron wire was commonly used to make "Cards" that were used to remove stuff from Sheep's wool prior to spinning.  If you know about the beginning of Copper wire please let me know.

Starting about 1840 the telegraph that uses current through a wire to activate an electromagnet started.  By 1865 there was over 83,000 miles of telegraph wire being used in the U.S.

Even though the telephone came into service there were still telegraph offices and rail road telegraph systems in use up into the 1950s.

The early telegraph systems were powered by wet cell batteries.  Later some were powered by the Edison DC utility.

Although the very early telegraph equipment tried to allow for a non skilled operator (Morse's patent was for a machine that printed a strip of paper with dots and dashes), the method that won out was based on an operator trained to recognize the sound of the Morse characters on a "Sounder".  This was much faster than other methods.

But later the Hughes Printing Telegraph was used on high volume lines to increase throughput.  This machine has a keyboard that came from a piano.


In 1873 there were more than 150,000 miles of telegraph lines in the U.S. alone operated by Western Union who had bought up most of the smaller companies.

When A. G. Bell invented the telephone he used a coil that was very similar if not exactly the same as those used for telegraph sounders.
A. G. Bell patent # 174465 Telegraphy, March 7, 1876   379/167.01; 178/48 - Note the patent title is Telegraphy because although it covers sending voice over a wire it's main intention was to allow for multiple telegraph circuits on one wire by using different audio frequencies.  Multiplex is the term for doing this.  T.A. Edison invented one of the ways to do this.


A simple telegraph system using Morse code operates by making and breaking the circuit.  With the circuit open the sounder spring holds the arm up.  When the circuit is closed current flows energizing the electromagnet in the sounder and the arm is smartly pulled down making the click sound.  When ham operators are working CW mode the transmitter is turned on for a tone and off for a space.  The problem with this Make-Break system is that during the break (space) time no signal is being transmitted.  That degrades the signal to noise ratio compared to a system where there is always something being transmitted.

When RTTY (Teletype) is being transmitted it's typically done using frequency shift modulation.  That way the transmitter is always on and a good receiving modem can provide 100% copy with either signal (it automatically combines both signals).

There was a problem when early Tickers were being installed where the transmission lines were long.  When on mark the tickers would work correctly, but on space, like when the operator was not doing anything, all the interference from adjacent telegraph lines would cause the type wheel to move a tick or two getting out of unison.  One fix for this was to add a resistance across the transmitter so that when in the break (space, open) condition a small current was being pulled.  But a better solution would be to use a protocol where the polarity was reversed and at no time was the circuit opened.  I think this is the way later model tickers operate.

Ticker Tape

Stock ticker machines work on the step-by-step principle that's very similar to today's "atomic" clocks.  There's a solenoid that pulls on a ratchet wheel advancing the type wheel (second hand) one position at a time.  By using either a positive connection to the battery or a negative connection it's possible to either step the type wheel or print a character.  The problem that plagued this system for a few decades was how to keep all the type wheels in unison.  There's a patent class just for Unison Devices.

Photo from EdisonTicker.comThe letter type wheel is above the figures type wheel and the separation makes it easier to read the tape.  By splitting the characters onto two wheels cuts the time per character in half, since a single shift operation is required rather than turning a single type wheel to the next character.  Stock prices used to be reported in 1/8 of a dollar increments.  There have been different ways to get the fractions printed.

The type wheel is advanced one position by sending one pulse on the telegraph line.  So there's a ticking noise while the wheel is turning then a louder noise when the character is printed.  This was so noisy that the machine was enclosed under a glass dome.  The dome is to cut down the noise, not for show.

 The effort to come up with a telegraph system that would not require a skilled operator led to the stock Ticker Tape machine (last model intro in the 1960s) which lead to the teletype machine, the first form of digital communications both first patented in 1869.  Bunnell made paper tape winders used for Morse pen recorders, fire alarm pull box recorders (Gamewell) and ticker tape.   IEEE history of the Ticker Tape machine.

The above is in Teleprinter font and is the shortest (33 letters) version of this pangram.  See:

The machines were made in volume by Edison, Western Union, Burry, New York Quotation, Commercial Telegram, Gold & Stock, Western Union in the early 1960s ordered that all existing Ticker Tape machines be destroyed, so today they are scarce.  There probably were over 20,000 of them at the time.

Once a day for about an hour test messages came out of New York from Western Union.  These would include the THE QUICK BROWN FOX JUMPS OVER THE LAZY GREEN DOG, the alphabet in order, the shifted characters in order, etc.  The machines ran on typical teletype loops of about 100 volts.

Ticker Tape machines were replaced by computers using modems, and now the internet.  When that happened they were still used for ball games and gambling.

A system of letting everyone know stock prices at exactly the same time is fair.  If conventional teletraph is used then the operators at either the sending or receiving end of the line may leak sensitive information.

By 1919 Western Union had bought up hundreds of telegraph related companies.  They then supported the following ticker machines:
When searching some key phrases are:
stock ticker
ticker tape

Ticker Tape Patents - 18 Mar 200 7 - 414 patents (about 240 MB) all realted to tickers or something very close.  Still many questions to be andwered.  Have T.A. Edison's papers on order.

UK 14403 1901 - 18 Feb 2007 have ask how to get a copy.  Appears on machine at Early Tech. Another 350600739 , 2135618081, 1855419371,

A guess at the Letters and Figures type wheels (based on Fig 4 in 126532):


Gold & Stock high speed ticker
1934 Black Box ticker

Stock Ticker Links

Edison, his life and inventions - Stock Ticker
Universal - 243, 332, 1292, 2030, 2101, 2106, 2187, 2313, 2351, 2391, 2408, 2712, 5777
NY Quotation Ticker
Berner Machine Labs - Makes non working metal life size model
Claus Studios - makes a hand painted plastic non working model & has some real items


The ticker type printers use a pulse to advance the print wheel one character.  If  you have just printed "B" and now want to print "A" you need to pulse the wheel N-1 times (N is number of characters on the wheel) which may be 26 + 10 + 10, i.e. a lot of stuff transmitted for only one character.  The teletype uses what's called a permutation (a key word appearing in patents) code where the number of bits for every character is the same and a binary sequence is used.  The first Baudot French patent was for a piano type keyboard with 5 keys.

When the teletype machine is in idle (stop, marking, make) position line current holds the selector in a fixed position.  When a key is pressed the line is opened (break, space, start) the selector is released and is turned by a local electric motor.  This start-stop method shows up in patent 1286351 by Krum.  at the end of one rotation the selector stops leaving the line in the idle state.  Computers call this asynchronous operation since the start time of each character depends on when the operator presses the key (random).  In the data stream prior to a letter the line has current so the start bit is the one that opens the circuit releasing the selector.  The start bit is followed by data bits, at first 5 an later 8 data bits, then in order to always leave the line with current the stop bit ends in the line closed state.  Because of the inertia of the machines in order to be sure the selector stopped 1 1/2 or 2 stop bits were used at the end of each character.  This same Start-Stop system is used today in the RS-232 and other asynchronous data schemes.

This system has a couple of big advantages over the step-by-step system.  First it is much faster to have all the characters much shorter on average than the step-by-step system.  For example the number of bits needed for the step-by-step system is on average 1/2 the number of characters on the type wheel, which would be around 30, so 15 bits per character.  The 5-level Start-Stop would have 7 bits per character so the throughput is already more than twice as high.  Also since the system synchronizes at the start of each character there are no Unison problems.

The other thing about Start-Stop is that you can design the assignment of bits to each character in such a way that it's easy to decode then mechanically.  The Step-by-Step sending machines needed to use either a circular keyboard or a piano type keyboard because of the rotation of the commentator and the alphabetical order of the letters on the type wheel.

Overview of Teleprinter Model Numbers

Numbered models are pretty much a Bell System thing.  Some model numbers were assigned to machines that were never produced.  The comments are not mine but belong to Walt.

Model 10 - Western Electric machine, by Pfannenstiehl et al  Typebar page printer with stationary platen
Model 11 - Morkrum, typewheel tape printer Model 12 - well-known machine, Morkrum, typebar page printer with moving platen
Model 13 - Model 10 retrofitted with Morkrum Model 12 typing unit
Model 14 - well-known Morkrum machine  It seems, according to the catalog, that the GPE perforator and XD transmitter-distributor were also considered part of the Model 14 line. (Western Union called it the 2-B)
Model 15 - well-known Teletype machine
Model 16 - a stock ticker that was not produced because of the 1929 depression.  Design was by Walt's group.  It had dual type baskets, one for letters and one for figures.
Black box stock ticker - did not have a model number.  (called 5-A by Western Union)
Model 17 - Designed by Kleinschmidt, a Hellschreiber-like machine.  Don't know if it could interoperate with a real Hellschreiber.
Model 18 - Kleinschmidt designed page printer for Western Union.  Not manufactured.  It had a lot of parts in common with the 21-A multiplex tape printer, but was a simplex (i.e. start-stop) machine.  (Since then I've found a parts manual for Model 18, so maybe it was  manufactured.)
Model 19 - well known Teletype machine  There is also the DPE perforator, being a perforator-only version of the Model 19 keyboard.
Model 20 - fairly well known machine, up/low 6-level version of Model 15 used for Teletypesetter
Model 21 -  The Western Union 21-A multiplex tape printer that has a few parts in common with Model 14 (Peculiar case where the Western Union model number seems to be the Teletype model number too.)
Models 22, 23, 25 and 27 - Walt doesn't remember anything about them. Probably machines that were designed but not manufactured. Model 24 seems to be an early version of Model 26, lacking some features of the latter.  Which means the typewheel positioning mechanism is based on the stock ticker.
Model 26 - fairly well known machine.  Was intended to be a low-cost machine for TWX service.  It turned out that by concentrating on one model, the Model 15, they could achieve the cost-reduction goal more easily.
Model 27 - referenced in museum book - says that is the model number for TT-4/TG (XC-2) a proposed military machine with a typing unit like a Model 26 and a keyboard like a Model 31.  Says only 10 units were made.  Note that the production TT-4/TG is a Kleinschmidt machine.
Model 28 - well known machine.  10,000 of them were ordered by the Navy before it went into production.  Sales wanted to give it a new name or model number to indicate it was a complete break with the past; but Bell Labs insisted that model numbers continue in sequence.
Model 29 - One tradition says this was to be a 28-line replacement for the Model 20, and didn't sell.  Then there was the Model 28 IDP ASR
   set which a lot of us called the Model 29, rightly or wrongly.  But this is not inconsistent, since the IDP set used 6-level BCD computer code and the Model 20 replacement used 6-level TTS code.
Model 30 - Walt doesn't remember.  There was a lightweight page printer project for the military that was also an ancestor of the 32/33 line.  The military project went nowhere because they chose the Kleinschmidt design, wanting to have a design they could own.   maybe the Navy Teletype TT-242 that lost  out to MITE...
Model 31 - fairly well-known machine.  Lightweight portable tape printer. Used a type sector printing mechanism similar to SIGABA.
Model 32 - well known - 5 level low cost light duty
Model 33 - well known - 8 level low cost light duty   Initially there was no interest from either the Bell System or Western Union in light-duty machines.  Teletype pushed ahead with development.  The Canadians brought in European Telex, and W.U. saw this as an opportunity to connect with European Telex and compete with TWX, so they very suddenly got interested in the Model 32.  A Model 28 had a life of 10-12 years in 24/7 service, which meant that in typical TWX service it had a life of over 50 years.
Model 34 - a Model 28 in Model 35's clothing Model 35 - well known - 8-level version of Model 28
Model 35 - an  Model 28 in Model 35's clothing Model 35 - 5 level version
Model 36 - Monopulse system, circa 1948.  Don't know why the model number jumped way up at that early date.
Model 37 - fairly well known.  Aggregate motion printer produced in stock ticker and page printer versions.
Model 38 - fairly well known.  Up/low version of Model 33.
Model 39 - Walt doesn't know.  Was after he retired.
Model 40 - well known
Model 41 - Walt doesn't know.  Was after he retired.
Model 42 - Was this reserved for a 5-level version of Model 43.  has been confirmed by Wayne
Model 43 - well known dot matrix page printer.
Models 44xx which were cost reduced and simplified Model 40s
Models 45xx which were enhanced Model 40s with newer electronics

Also - Teletype would make single copies of machines, or dummy machines,
   to demonstrate concepts.  Walt mentioned that in particular they would
   do this at the request of young Navy officers.  Old Navy officers already
   had their careers made, but younger ones were trying to make names for
   themselves and Teletype was happy to help them.

16 Mar 2007 - Following is a small sample of patents, I've found over 300 so far relating to Step-by-Step equipment, mostly for stock tickers.

151209 Automatic Telegraphy and Printer Therefor, T.A. Edison, May 26, 1874, 234/106 ; 178/17R
638591 Actuating Mechanism for Key Operated Machines, D. Murray, Dec 5, 1899, 400/75 ; 234/70; 400/415; 400/478
65393 Page Printing Telegraph, D. Murray, 4 July 17, 1900, 178/25 ; 178/4; 178/92; 199/18; 234/82
685427 Automatic Actuating Mechanism for Key Operated Machines Oct 29, 1901, 400/75 ; 400/376; 400/415; 400/478
698845 Actuating Mechanism for Key Operated Machines, D. Murray, April 29, 1902, 400/75 ; 400/478
710163  Keyboard Perforator, D. Murray, Sep 30, 1902, 234/105
888335 Printing Telegraph, K.L. Krum, May 19, 1908, 178/27
862402 Printing Telegraph, K.L. Krum, Aug 6, 1907, 178/27 ; 178/40
929602 Transmitter for Electric Telegraphs and the Like, C.L. Krum, July 27, 1909, 178/79 ; 340/815.89
929603 Transmitter for Automatic Telegrapher, C.L. Krum, July 27, 1909, 178/33R
1137146 Printing Telegraph Apparatus, C.L. Krum, April 27, 1915, 178/27
1286351  Electric Selective System, H.L. Krum, December 3, 1918, 178/33R ; 246/3; 246/5; 340/825.59 - Start-Stop method
1232045 Selective Telegraph System and Apparatus, C.L. & H.L. Krum, July 3, 1917, 178/27 ; 400/155.1; 400/157.2; 400/320.1; 400/470
first use of start-stop patent
1326456 Telegraph Transmitter, C.L. & H.L. Krum, Dec 30, 1919, 178/17A ; 234/89- paper tape
1360231 Printing Telegraph, C.L. & H.L. Krum, November 23, 1920, 178/4 ; 178/23R; 178/33R- paper tape
1366812 Selective or Printing Telegraph, January 25, 1921, 178/17B ; 178/17R; 226/37; 400/73- paper tape
1635486 Printing or Selecting Telegraphs, C.L. Krum, July 12, 1927, 178/27 ; 178/17.5- keyboard start-stop
1665594 Telegraph Printer, H.L. Krum, April 10, 1928, 178/27 - No. 12 Tape type Printer
1745633 Telegraph Receiver, S. Morton (salt), Feb 4, 1930, 178/27 - No 14 Typebar Tape Printer
1904164 Signaling System and Apparatus, S. Morton , April 18, 1933, 178/4 ; 178/23R; 178/27; 178/33R; 220/2.3R - No. 15 Page Printer
1374606 Printing Telegraphy, H. Pfannenstiehl, April 12, 1921, 178/27 ; 400/184; 400/70- 10-A teletypewriter
1426768 Printing Telegraph Receiver, H. Pfannenstiehl, August 22, 1922, 178/27 ; 178/69.6; 400/140; 400/184; 400/185; 400/253; 400/372; 400/72
1623809 Printing Telegraphs, H. Pfannenstiehl, April 5, 1927, 178/27 ; 199/18; 400/70
1661012 Automatic Impulse Transmitter, H. Pfannenstiehl, February 28, 1928, 178/17A
1151216 Selective Electrical Signaling Apparatus, L.M. Potts, Aug 24, 1915, 178/33R - reed type start-stop selector
1229202 Telegraphic Receiver, L.M. Potts, June 5, 1917, 178/27 ; 101/110; 178/29; 370/305; 400/154.1; 400/471- 8 level code
1370669 Machine Telegram, L.M. Potts, March 8, 1921, 178/27 ; 101/93.36; 178/2F; 178/34; 178/4.1R; 178/69.6; 234/37
start-stop purmutation code
1517381 System of Telegraph Distribution, L.M. Potts, Dec 2, 1924, 178/17E ; 178/17R; 370/304 - trunk mux, Western Union Telegram
1570923 Printing Telegraphy, L.M. Potts, Jan 26, 1926, 178/27 ; 400/154.4; 400/155 - gum backed paper strip, Western Union Telegram
2181708  Printing Telegraph Apparatus, A,H, Reiber, Nov 28, 1939, 178/35 ; 178/33MP; 370/305; 400/155.1; 400/157.2

Computer Code Development Patents

The Teletype machine 5 and 8 level paper tape codes evolved into today's 8-bit ASCII code.  Note that keyboards, printers, tape and card punches all used a more or less common code.

1274484 Tabulating Machine and Cards Therfore, R.N. Williams, Aug 6, 1918, 101/96 ; 235/432  
1880408 Alphabetical Code Punching Device, J.W. Bryce, Oct 4, 1932, 234/96 ; 234/103
1902060 Printing Mechanism, P. Dechene  Mar 21, 1933, 101/93.25 ; 101/110; 101/93.44; 235/432
1867025 Combinatorial Hole Punch, J.R. Peirce, July 12, 1932, 234/37 ; 234/102; 234/119; 234/129; 234/18; 235/434; 235/59T
1926892 Printing Mechanism, J.W. Bryce, Sep 12, 1933,  101/96
1896555 Rotary Printing Machine, J.R. Peirce, Feb 7, 1933, 101/93.26
1981990 Printing Mechanism, F.M. Carroll, Nov 27, 1934, 101/93.46
2010652 Printing Mechanism,  G. Tauschek, Aug 6, 1935, 400/141 ; 101/109; 101/399; 101/93.45; 101/93.46; 178/4; 235/432; 400/157.2; 400/161.4; 400/174; 400/62
2016682 Printing Mechanism, A.W. Mills, Oct 8, 1935,  101/93.46

89887 Printing Telegraph, G.M. Phelps, May 11, 1869 178/38 ; 178/41
RE004152 Printing Telegraph, G.M. Phelps,Oct 11, 1870, 178/41
143702 Improvement in Printing-Telegraphs, Landy T Lindsey, May 3, 1873, 178/41 - this is the now classic teletype machine that uses a start and stop bit to sync the receiving machine at every character.

(Five Level) Tape Distribution System, L.M. Potts (Teletype), Sep 4, 1945, 178/17B ; 178/42; 226/115; 242/532.6; 242/534.2; 83/70

Table of 5 Level Teletype Code

0= space (line open), 1=Mark (line has current)

Prior to the start of a character there's current in the line (mark) holding the selector electromagnet.  Each of the 32 characters always starts with a space condition (line opened to release the selector) and the end is always a mark (current in line to hold the selector still).  This is not shown in the table, just the 5 character elements.  The code elements are sent left to right.  For example to send A:
The line has current (mark),
the start bit (space) is sent for 1 time unit,
a mark is sent for 1 time unit,
a mark is sent for 1 tine unit,
a space is sent for 1 time unit,
a space is sent for 1 time unit,
a space is sent for 1 time unit,
the line is put in mark for at least 1-1/2 time units (maybe 2 time units)

All letters are CAPITAL, there are no lowercase letters in the 5 level code.

Arranged Alphabetically
Arranged by Code
<pound Sterling>
Carriage Return
Line Feed

00001 T
Carriage Return
<pound Sterling>
Line Feed
01010 R
01011 G
01100 I
01110 C
01111 V
10000 E
10001 Z
10010 D
10011 B
10100 S
10101 Y
10110 F
10111 X
11000 A
11001 W
11010 J
11011 Figures
11100 U
11101 Q
11110 K
11111 Letters

Punched Paper Tape

5, 6,
                  7 & 8 Level punched paper tape specs
The 3 data holes between the sprocket holes and the edge of the tape are the same for 5, 6, 7 & 8 level tapes.
The holes on the other side of the sprocket (marked "B" in the drawing) change in number, either 2, 3, 4 or 5 holes.

On the Model 33ASR Teletype the plastic cover that holds down the paper tape has a "V" shape so when you pull up the paper the tail of the punched tape has a "V" notch at the end.  The paper still in the machine has a point at the beginning like an arrow.  So you know which end is which. 

I used an electric eraser with a custom built accessory that was a metal rod with a disk at the end.  The disk had a couple of 1" high pins sticking up.  This would allow winding up a long paper tape very quickly.  If done correctly the pointed end would be on the outside.

Telegraphic Fire-Alarm Recorder

These recorders write on the paper tape the number of the box making the call.  They need to be very reliable and maintenance free.  Many have glass panels to allow viewing the inside without opening the box up which may cause problems (probably like something getting inside that shouldn't be there).  The most common name was Gamewell.

Note that when one of these recorders is connected to a dial telephone line in a certain way when the phone dials the recorder is started and records the dial pulses on the paper tape.  One of these machines could be left for a long time with no maintenance.  Maybe once a week or month someone would come by and tear off the printed tape.  There is no time stamping or any indication of when a call was made, just the number dialed.

Dr. William F. Channing & Moses G. Farmer Boston, 1852.
Class 178 is Telegraphy oldest 1837 about 13,400 patents
Class 340 is Communictions Electrical oldest 1840, about 88,888 patents

120395 Improved Fire Alarm and Police Signal Box, W.J. Philips, Oct 31, 1871, 340/288 ; 178/2R
127844 Improvement in District and Fire Alarm Telegraphs, E.A. Calahan, Jun 11, 1872, 340/295
146603 Improvement in Electric Bell Striking Apparatus, L.H. McCullough, Jan 20, 1874, 340/398.1 - alarm bell
146698 Fire-Alarm Telegraphs, L.H. McCullough, Jan 20, 1874, 340/295 - Once a box starts to send an alarm, all boxes further from the station are cut off to prevent multiple alarms.
146812 Telegraph Signal Boxes, T.A. Edison, Jan 27, 1874, 340/295 - referrences E.A. Calahan 127844 prior art
147186 Improvement in Morse-Telegraph Registers, John E. Smith, Feb 3, 1874, 178/95 ; 178/92 - auto starting, only dots & spaces for fire reporting
148215 Telegraphic and Thermostatic Fire Alarms, A.F. Johnson, Mar 3, 1874, 340/535 ; 340/542
148833 Fire-Alarm Telegraphs, J.F. Kirby, Mar 24, 1874,  340/304
149677 Improvement in Electro-Magnetic Alarms,  F.L. Pope, Apr 14, 1874, 340/392.1 - feedback to keep it ringing
150513 Telegraphic Fire-Alarm Boxes, J. Beamer, May 5, 1874, 340/307 ; 178/83
153498 Electric Signaling Apparatus, W.H. Sawyer, July 28, 1874, 340/294 - repeats house # to indicate the type of help needed
153958 Fire-Alarm Telegraphs, A. Halbrook, Aug 11, 1874, 340/815.58 ; 976/DIG.65; 976/DIG.68; 976/DIG.69 - time delay as signal
155207 District Alarm-Telegraph, W.D. Snow, Sep 22, 1874, 340/535 ; 178/86; 200/33R; 340/292; 340/592
155208 Electrical Thermostatic Alarms, W.D. Snow, Sep 22, 1874, 340/592 ; 340/393.2; 374/141; 374/201
156114 Fire Alarm Registers, J.O. Alley, Oct 20, 1874,  340/815.69 ; 377/92
157002  Electric Fire-Alarm Signal-Boxes, Z.P. Hotchkiss, Nov 17, 1874, 340/301 ; 70/339; 70/454
158715  Telegraph Signal Apparatus (Hotel), J.W. Kates, Jan 12, 1875, 340/293 ; 178/17R
169087 Fire-Alarm Telegraph, Oct 26, 1875,  340/291 ; 178/3; 178/73; 340/295
1779664 Code Register, L. Degen, October 28, 1930, 346/93 ; 178/42; 346/105
380779 - Message Recording Aparatus, F.A. Skelton,Octr 26, 1909, 346/77R ; 178/92; 346/146; 346/78 - police system, ink pen type
938285  Electric Signal Recorder, N.H. Suren, Oct 26, 1909, 346/50 ; 178/92; 346/136; 346/141; 346/77R; 83/70 - Gamewell
938286 Electric Signal Recorder, N.H. Suren, Oct 26, 1909, 178/92 - Gamewell
938441 Message Recording Aparatus, F.A. Skelton, October 26, 1909, 346/77R ; 178/92; 346/146; 346/78 - slot instead of ink - Gamewell
1204214 Signal Recorder, L.J. Voorhees, November 7, 1916, 83/70 ; 83/203; 83/221; 83/283; 83/628; 83/632; 83/698.91 - spring wound, for Fire, Police, etc.
1840653  Fire Alarm Recording Device, L.W. Bills, Jan 12, 1932, 83/70 ; 83/524; 83/602- glass end & top plates
1879175 Punch Register for Recording Electrically Transmitted Signals, etc., M. Garl, Sep 27, 1932, 83/70 ; 74/88; 83/247; 83/617
1923403 High Speed Tape Recorder, L.H. Webb, Aug 22, 1933, 83/70 ; 178/17A; 178/92; 340/287; 346/79; 83/234; 83/572 - typewheel slides on shaft allowing printing across a page.  Probably how the "Broad" stock tickers work.


Bunnell Straight KeyThis is a Bunnell key made according to the Bunnell patent 237808 and is the standard design for a straight key.
The shorting lever is an important part of the key needed to accomplish the repeater system patented by professor Morse.

The shorting lever was also used on keys used with radios, but there it is of little use but probably it's easier for a manufacturer to make one product than make different versions.

Note that the frame of the key is one of the electrical contacts and so the metal that's holding the insulated key knob may be "hot" if the key is switching the High Voltage.
1109310 Telegraph Key, September 1, 1914, 178/82R - bug


Bunnell 150 Ohm RelayRelays were commonly used on the main line to control the local loop.  Main lines might be up to a few hundred miles long depending on the gauge of wire used and the quality of insulation.  Larger wire is needed for longer lines and good insulation is needed to prevent leakage currents to ground.  Also more batteries are needed.

Another use for relays is in pairs to form a repeater allowing two way signaling on lines too long for a single loop.

The relay would have a 150 Ohm coil.  The coils are 1 5/16" diameter, larger than the 1" coils on the sounders.

The coils are wired so that their magnetic fields add.  If they were mechanically arranged in series (i.e. wire end to plain end) then the connecting wire would be inside to outside.  But the coils are mechanically arranged with both wire ends pointing down (looks better) so the connecting wire is inside to inside (could also be outside to outside).  This way the reversal of mechanical position and the reversal of the wiring results in aiding magnetic fields.

There's a fine wire connecting the armature frame to the armature hinge.  What is it for? Ans.  there is a small hole nearby in the moving armature and the wire is meant to connect between the frame and armature so that the switched current does not need to travel through the joint.  Need to find a small brass screw to replace it.

The coils can be moved back from the armature to allow for leakage resistance to ground during storms or on poor quality lines.

Also the spring is missing.

The adjustment that moves the coils away from the armature is used to counter the effect of leakage currents on the line.  With no leakage the most sensitive position would be with the coils close to the armature.  But with leakage you need to move the coils away from the armature.

Note that there are two coils instead of a single coil.  This is done to increase the amount of magnetic field for a given amount of wire.  Winding more wire on a single coil does not add as much field as using that wire on a second coil.  In many applications you will see dual coils.

The core for a common electromagnet is "soft" iron.  Meaning it's easy to magnetize.  The higher the initial permeability the better.  There are some patents for iron alloys that work better than just plain iron.  It may be that a good electromagnetic would make a good flux gate sensor.

28274 Telegraph-Relay Instrument, A.G. Holcomb, 361/206 ; 178/102 - dual coils & magnet with bi-polar drive
29247 Improvement in Telegraphic Repeaters, J.J. Clark, Juy 24, 1860, 361/191 ; 178/71.13
162633 Duplex Telegraph, T.A. Edison, April 27, 1875, 370/276 -
480567 Duplex Telegraph, T.A. Edison,Aug 9, 1892 

Pole Changer

A relay that reverses the battery polarity powering the telegraph line.  Typically used for duplex or quadraplex circuits.
379062 Pole-Changer, E.M Hamiltion, Mar 6, 1888, 361/246 - does not use a permanent magnet
an example of a clock face pole changer is on the Reverse Time Page - Western Electric Pole-Changer Relay
The relay contacts were behind a round glass which looked sort of like a "clock face".

255A Polar Relay

By combining a permenant magnet with the magnetic field from the coils the direction of movement of the armature depends on the polarity of the input.  Polar relays were used in many applications, and I'm trying to find out the application for this model.  Also what the adjustments do.

The coils of this model can be connected directly to the RS-232 output from a computer COM port (RS-232 is a bi-polar signal).  The points can switch the loop current for a RTTY machine where the loop voltage is on the order of 200 Volts.  This might also be used to allow a computer to drive the WU5A stock ticker.

I've been told this is a specalized version of the WECo 280-type relay.  The plug-in base is for use in teletype equipment.

255A Polar
255A Polar
255A Polar

1578707 Electromagnetic Device, W. O. BECK (Western Electric), Mar 30, 1926, 335/81 ; 200/303; 335/83; 335/86; 439/680 - very close to this one
Common contact
Coil 1 *
Coil 2 *
Positive contact
Negative contact
Coil 2
Coil 1
For RS-232 drive jumper 3 to 7 and drive 2 & 6.  Use 1 & 4 to interrupt the TTY loop.  This wiring draws 70 ma @ 10 volts.  Once the relay has changed states it stays where it was left after the drive has been removed.  But it seems to stay in one position more than the other.  The adjustments might improve that.

17-B Polar Relay

This is a SPDT relay with 4 coils.
The top label reads:
WU. Tel. Co.
Polar Relay 17-B
Pat'd 12-14-15   Others Pending
Mfd by Westinghouse Electric & Mfg Co.
Newark Works, Newark, N.J. U.S.A.

Notice that this polar relay has a "U" magnet and the 255 polar relay just above also has a "U" magnet.

Western Union WU 17-B
                Polar Relay
Western Union WU 17-B
                Polar Relay
Western Union WU 17-B
                Polar Relay
Western Union WU
                17-B Polar Relay Western Union WU
                17-B Polar Relay

Polar Relay Patents

702339 Telegraphic Apparatus (tape punch), Sidney George Brown, Jun 10, 1902, 178/92; 83/70; 83/575- better detection of long cable signals by reversing the current.
1150326 Electromagnetic Recording Apparatus for Telegraph Circuits, A.H. Annand, Aug 17 1915 -uses polar relay.
1160097 Telegraph Repeater, W. Finn (Western Union), Nov 9 1915, 178/71.5 - for high speed (not hand sent) telegraph
    RE14304 Relay and Repeater, W. Finn (Western Union), May 22 1917 -
1163883 Selective Signalling Device, SPC Boswau, (Western Electric Co), Dec 14, 1915 - part of a step by step system
1164069 Call Box, A.A. Clokey (Western Union)
1164274 Telegraph-Repeater, W. Finn (Western Union), Dec 14 1915, 178/71.13 -
1350193 Attachment for Cable Recorders, F.S. Whitney, Aug 17 1920
1749738 Automatic Stroke Corrector Circuit, A.J. Finn & P.L. Myer (Western Union), 178/70.00A, Mar 4, 1930
2212634 Relay Testing Method and Apparatus, W.D. Buckingham (Western Union), Aug 27, 1940, - uses CRT to test polar relay
2592779 Tape Controlled Telegraph Transmitter, R.J. Wise, R.D. Parrott (Western Union Telg Co), Apr 15, 1952 -
single row with dots & dash photocell
RE18756 Resistor Cell Circuit, C.F. Jenkins (Jenkins Labs), Mar 7 1933 - was 1693509
  836710 Line Printing Slug
1144236 Transmitter or Reproducer, W.E. Peirce - single line dot and dash sender from paper tape
1326864 Selective Controlling Apparatus for Electric Circuits - player piano
1826858 Photographic Printing Apparatus - motion pictures
1953072 Remote Control Advertixing and Electric Signaling System, - optical read 5 level punched paper tape
1972555 Kinetographic Apparatus - movie related
1981255 Motion Picutre Projector
2064049 Combined Motion Picture & Talking
2064050 Sound Gate
2177077 Photoelectric Transmitter
2266349 Method of Producing Holes . .
2307099 High Speed Teelgraph System, G. Apperley (RCA), - optical
2313583 Modulating System
2317850 Electro-Optical Facsimile Synchronizing System - drum fax
2332142 Long Dash Interrupter, (RCA) -
2353608 Printing Telegraph Apparatus, W.J. Zenner (Teletype Corp), Jul 11 1944, 178/42; 226/45; 226/196.1; 242/615.3 -
center traction holes and dots on one side and dashes on the other side
1997601 Automatic Control Mechanism, A.H. Reiber (Teletype Corp), Apr 16 1935 - taught tape punch to reader
2382251 Telegraph Perforator-Transmitter (Bell Tel), - 5 level
2403918 Method of Operating the Electronic Chronographs, (RCA)

Dial Telegraph

Similar to a clock face with a single hand that can point to all the letters of the alphabet the digits 0 through 9 etc.
See separate web page Dial Telegraph.


Sounders were the most common means of receiving telegraph signals by 1859.

4 Ohm 1895 pat date4 Ohm sounders are for local loops (under say 100 feet) and practice boards.  20 Ohm sounders are for up to 15 mile lines.  Higher (say 150) Ohm sounders are for very long lines. 

This is Bunnell serial number 62 as received.  So far I've found 4 parts all with the number 62 stamped on them so assume that's a serial number.  All the brass has tarnished and the coils test open.  The coils are OK just a bad connection to the terminals.

 The lever are is marked: J.H. Bunnell:?? New York. U.S.A.
On the bottom of the wood is the marking:
  I.R.S. 11 18 which may mean Internal Reapir Station Nov 1918

The modern screw and nut on the yoke is a 6-32 that's a sloppy fit.  The correct thread is a 6-40.
I have taken this sounder apart and am polishing the brass and after steel wool on the wood treating it with Tru Oil gun stock finish.
Then plan to use Everbright on the brass.  The steel will be painted flat black.
The 8-40 tap worked to chase the thread and now the stop and lock nut fit properly.

Non Interchangeable parts

An interesting thing about this sounder is that the dimensions are not close to common rounded dimensions.  The O.D. of the coil covers is very close to 1 inch, but all the other dimensions seem strange (not metric).  Maybe the number "62" that appears on many parts relates to a bin number for selective assembly rather than a serial number?  Or maybe it's the employee number of the man who made it?

Note it was not until the end of the Civil War (1861 - 1865) that tolerances and interchangeable parts started to appear in the U.S.  So prior to 1861 telegraph equipment would be made by skilled craftsman and would not have interchangeable parts.

It wasn't until 1864 that the U.S. adapted the National Coarse (NC) and National Fine (NF) thread specifications.  Prior to that each shop probably used whatever they had on their lathes.

Machine Tools Time Line by the ASME

136 Ohm Bunnell SounderThis Western Electric sounder has 1 1/16" O.D. coils and is marked "Sounder 3C 140 Ohms" and "F9003C".  On the bottom it has the two conical feet like the above sounder and has a couple of wooden rods with mounting screws through them like the above sounder.  This one is complete and the coils test good as received.

It may be that the Main Line sounder was a development of the late 1800s that was intended to replace the need for the relay.  Note that with a sounder that would work directly on the main line things get much simpler.  A relay can only be used in one direction so needs either an operator between the two end stations or seperate wires for send and receive.  In either case a main line sounder would be a big cost savings.

20 Ohm Bunnell SounderThis sounder is a 20 Ohm Bunnell and looks very similar to the 4 Ohm soundere above.  But it does not have the 1895 patent (see below) notice on the brass reasonator plate.  The coils are larger at 1.3" OD. 
The lever is marked J.H. Bunnell, New York.

In the early days of telegraphy a relay was used on a long line and then 4 Ohm sounders can be used in the local loop.  Battery was typically supplied at each end of a line by either Gravity and later Leclanché cells.  The number of cells goes up like one cell per mile of line and per sounder.

A good Sounder makes noise when a feeble current is present.  So a figure of merit might be how much sound it makes and what is the minimum current needed for good operation.

A sensitive relay might also be driven my the main line and then the relay contacts would drive a local 4 Ohm Sounder.  Since the mass of the relay armature is much lower than that of a Sounder, it would operate with less current hence be more efficient.

A practice board can be run from a single wet battery (i.e. a little over 1 volt).

5 1/2" x 3" base sounders
Pull In
End Play
Air Gap

< 120
Local Battery
< 50
.015 .016/.005
Main Line
< 20
.015 .016/.005

< 42
.015 .016/.005

< 10
.015 .016/.005
Local Duplex (2 metal contacts)


< 65
159894 Telegraph-Sounder, J.H. Bunnell, Feb 16, 1875 - see patents
190191 Telegraph-Sounders, J.H. Bunnell & M.W. Goodyear, May 1, 1877 - lower cost, easier for beginners
180700 Printing Telegraph, J.H. Bunnell, Aug 8, 1876 - really a stock ticker
255932 Mechanical Telegraph Sounder, J.H. Bunnell,Apr 4, 1882 - telegraph key knob on sounding bar & no electromagnet.
267833 Telegraph-Sounder, J.H. Bunnell,Nov 21, 1882 - wood sounding board mounted in cast iron base.


This was the first of a number of "counters" and "registers" patented by Mr. Veeder.  This one is a general purpose design that can be used in many applications.  Later versions were:

372994 Velocipede-saddle, Cuetis Hussey veeder, Nov 8, 1887, 297/205 - close to the modern spring wire narrow type still used.
548482 Cyclometer, C.H. Veeder, Oct 22, 1895, 235/95R; 235/117R; 235/139R - mounts to the hub of bicycle wheel. (ad at: RFD: Marketing to a Rural Audience)
D28078 Design for a case for registers, Curtis Hussey Veeder, The Veeder Manufacturing Company, Dec 21, 1897, D10/97; D10/70 - outer case for patent 548482 Cyclometer.
676519 Register, Curtis Hussey Veeder, Veeder Mfg Co, Filed: Nov 21, 1898, Pub: Jun 18, 1901, 235/97; 235/110; 235/117R; 235/144R; 235/144S; 235/47 - dual counters, one of which can be reset (like the trip and odometers in a car).
634073 Registering-Counter, Cuetis Hussey Veeder, The Veeder Mfg Co., Filed: May 17, 1899, Pub: Oct 3, 1899,235/117R ; 235/1C; 235/139A; 235/139R  - a single general purpose counter (note filed after the above patent)
732975 Tachometer, Curtis Hussey Veeder, Jul 7, 1903, 73/500 - not based on counters, but rather an analog instrument
733358 Tachometer, Curtis Hussey Veeder, Jul 7, 1903, 73/496; 73/500  - an analog instrument based on a vane type pump
741420 Odometer, Curtis Hussey Veeder, Veeder Mfg Co, Oct 13, 1903, 235/95R; 235/96 - sealed against the elements and can work quickly (not clear what vehicle it's for, maybe bicycle or automobile?)
740492 Machine for cutting off metal rods, &c., Curtis Hussey Veeder, Veeder Mfg Co, Oct 6, 1903, 83/199; 292/337; 82/59; 82/70.2 - can cut short lengths of rod from a spool without burs
751576 Steering mechanism for motor-vehicles, Curtis Hussey Veeder, The Veeder Manufacturing Company, Feb 9, 1904, 280/90 - adds hydraulic damper
826630 Tachometer, Curtis Hussey Veeder, Jul 24, 1906, 73/500 - an analog instrument based on a vane type pump
833355 Driving mechanism for odometers, &c., Curtis Hussey Veeder, Oct 16, 1906, 235/91R; 235/95R; 74/423; 74/810.1 - allows the odometer to be located on the dash board (this was before there were instrument panels) rather than at the wheel.
937015 Measuring or indicating instrument, Curtis Hussey Veeder, Veeder Mfg Co, Oct 12, 1909, 73/500 - improvement on 732975 & 733358 (see above), but still an liquid level tachometer, but counter added as odometer.
950546 Counter, Curtis Hussey Veeder, Veeder Mfg Co, Mar 1, 1910, 235/144PN; 235/117R; 235/144S; 246/191 - zero set mechanism
1000860 Register, Curtis Hussey Veeder, Veeder Mfg Co, Aug 15, 1911, 235/96 - cites his prior patents 548482 & 676519
1000861 Odometer, Curtis Hussey Veeder, Veeder Mfg Co, Aug 15, 1911, 235/95.00B - hub mounted, like used on truck axles
1002016 Odometer, Curtis Hussey Veeder, Veeder Mfg Co, Aug 29, 1911, 235/95.00B - hub mounted, like used on truck axles
1016906 Tachometer, Curtis Hussey Veeder, Veeder Mfg Co, Feb 6, 1912, 73/500 - liquid level tachometer, but counter added as odometer.
1015767 Tachometer, Curtis Hussey Veeder, Veeder Mfg Co, Jan 23, 1912, 73/500 - liquid level tachometer, but counter added as odometer.
1081561 Hub-odometer, Curtis Hussey Veeder, Dec 16, 1913, 235/95.00B, 301/108.2 - 
1093580 Setting glass, Curtis Hussey Veeder, Veeder Mfg Co, Apr 14, 1914, 52/204.62, 52/482 - how to fit glass window on his counter to make it weather tight
Hub-odometer, Curtis Hussey Veeder, Veeder Mfg Co, Jan 19, 1915, 235/95.00B - hub mounted, like used on truck axles
1196495 Register, Cuetis Hussey Veeder, The Veeder Mfg Co., Aug 29, 1916, 235/91.00R, 235/95.00B, 235/1.00A - on pumps, like used for gasoline
1149605 Manufacture of pawl-frames, &c., Cuetis Hussey Veeder, The Veeder Mfg Co., Aug 10, 1915, 72/324, 72/371, 29/893.2 - for use in his counters
2152394 Astronomical mirror, Veeder Curtis H, Mar 28, 1939, 359/849 - a truss system rather than solid glass for large mirrors with lower weight
This Electro-Mechanical counter has No. 7 engraved (stamped) into the wood just above the left binding post. Brand name is Veeder. Patented Oct 3, 1899.
Patent 634073
No. 7
                Electro-Mechanical counter
No. 7
                Electro-Mechanical counter Coil
                Electro-Mechanical Counter
 No. 7 Electro-Mechanical counter
The counter proper looks like the hand held type. 
No provision to reset.

634073 Registering-Counter, Oct 3, 1899, Cuetis Hussey Veeder, The Veeder Mfg Co., 235/117R ; 235/1C; 235/139A; 235/139R

The counter is a ratchet type where the lowest digit increments ten counts for each turn of the input shaft.  This type of counter shows up in all kinds of things.  Later called Veeder-Root counters.  For this application the lever translates the armature throw into 1/10 of a trun of the counter shaft.

Coil about 2 Ohms takes about an amp to actuate the mechanism.  There are maybe 5 wires coming from the coil all soldered toghther, i.e. the coil consists of 5 different coils connected in parallel.  This was a way to get a lower coil resistance with a much higher fill factor than you could get if you used a larger diameter wire.  The individual wires running under the base are about 0.014" dia.  Probably AWG 28 which is 65.1 Ohms/k', so 10 Ohms would take 154 feet for each of 5 coils or 768 feet.  The former is 1.600" long and the coil O.D. is 1.22 the I.D. might be 0.5" making for a window of 1.6 x .36 which can hold just under 3,000 turns which might amount to 600 feet of wire, so in the ball park.

But the spring is not pulling the arm high enough to let the ratchet pawl drop into the next notch so the count does not always advance.  This is caused by the electro-magnet core rotating and jamming the works.

Veeder Counter Hinge ScrewSome problems:
The brass lever arm is bent (marked "7")
The hinge screw has bunged up 2-56 threads at the tip -
This is because after the screw was installed the thread end was expanded
to lock it in place.  This can clearly be seen on the two screws that hold the
bracket to the electro-magnet.  No Loctite then.
The brass hinge screw has a rough surface where the lever pivots
Both the screw and lever are brass, better if one is a different hardness
There is nothing to keep the armature from turning and that promotes jamming the lever.  There are grooves on the cylindrical part of the armature, but no sign of something to ride in the groves.  Also on the bottom of the wood base there is a clearance hole that's extended up through the disk at the base of the electro-magnet to give access to a screw that goes into the bottom of the electro-magnet.  Why? "I suspect that it's an adjustable stop for the solenoid core." - David B.

Working Veeder
          Counter & Electro-magnet
7 Aug 2007 - 2-56 tap and die arrived so could clean up threads on screw (photo above) and it's hole in the bracket.

The fix was to stop the plunger from rotating.  It does have shallow grooves in two places, but I don't see anything to ride the grooves.  Maybe it was hidden from view and wore out.  The fix was to epoxy a paper clip to prevent counterclockwise rotation, which seems to be the only direction.

Some grease on the paper clip and clock oil on the joints and a tiny bit of  weak Loctite applied in the female threads so that only the last turn of the screw will see the Loctite.  That way the screw won't back out, but could be removed for future work.

          Electro-magnetic counter bottom

Still don't know what the bottom center screw is for and why it's accessible when the unit is assembled. Why?

A single "D" cell flashlight battery will not do anything, but two connected in series does cause the counter to work smartly.

ENM Electromagnetic Counter

ENM Counter

Engraved into the metal case:
6V    DC
4.08W    109CJ (SA)
Patent No. 3470361
ENM Company
Chicago, Illinois 60630
Made In U.S.A.
It works smartly at 5 volts and sluggish at 3.3 volts.
3470361 Counter, B.J. Wollar (ENM), Sep 30, 1969, -
a lower cost counter (than that above) aimed at things like photo copiers or vending machines.
in the photo above the armature is the sheet metal part just above the coil.  The plastic part on the right gets pulled down
and has grooves facing the fast wheel that act as an escapement.  Below and between each wheel is a gear free to turn on a shaft.  As a wheel increments from 9 to 0 a single tooth engages the gear and moves the adjacent wheel 1/10 of a turn.  At all other positions of the wheel the gear is frozen (the single tooth is more of a notch than a projection).
A copper clip holds the coil down.  The copper clip has been deformed so that it clamps the notch in the coil's central core.
4143749 Totalizer for Vending Machine,
3580498 Electromagnetic Counting Mechanism,
3761015 Electrical Impulse Counter with Shock proofing Mechanism
4270399 Counter Drive Mechanism,
3700163 Star wheel Operating Mechanism


439 Electrical Connectors
/623 Cable Composed of Mutually Insulated Conductors Having Separately Carried Conductor end Terminals
/651 With Insulation other than Conductor Sheath..Two or more plural-contact coupling parts combined in one integral unit...Unit includes receptacle for receiving plug having spaced, longitudinally engaging, prong-like contacts....Combined with plug having spaced, longitudinally engaging, prong-like contacts
/736 With Insulation other than Conductor Sheath .Metallic connector or contact secured to insulation..Secured by heat-molding or cold-deforming insulation or by casting, welding, or cementing
/808 Metallic Connector or Contact having Moveable or Resilient Securing Part.Screw-thread operated securing part..With strand coiling or loop forming means
/828 Metallic Conductor or Contact Having Movable or Resilient Securing Part.Spring actuated or resilient securing part..Clamping pressure provided by cantilevered finger resiliently urged away from opposed clamping member ...Pivotally or rotatably mounted member locks or places securing part into securing condition
/866 Metallic Conductor Terminal having Conductor Sheath Engaging Means.Pin or plug type terminal
/874 Metallic Connector or Contact Having part Permantently Secured to Conductor using Fused or Molded Material

403 Joints and Connections
/274 Member Deformed in situ

Binding Post

A binding post is an improvement on a screw and nut.
In the photos above of the Veeder counter notice that the two binding posts are made by using a stock screw and two thumb nuts.  The top thumb nut has the common straight knurl and the bottom thumb nut has no knurl.  So it's just a screw, two thumb nuts, a washer and a hex nut.

137810 Connecting-Post for Electrical Apparatus, T. Wishart, Apr 15, 1873, 439/817
140618 Screw-Post for Electrical Apparatus, S.D. Field, July 8, 1873 439/810 ; 256/DIG.3 - thumb screw
279274 Binding Post, W.R. Patterson, June 12, 1883, 174/94S ; 24/127; 24/130; 411/531; 439/808
296160 Binding Post for Electrical Conductors, A.G. Goodbody, April 1, 1884, 439/729
434892 Binding-Post, G.J. Scott, Aug 19, 1890, 439/807; 24/136.00B
446871 Binding Post, C.A. Lieb, Feb 24, 1891, 439/736 ; 411/389; 429/121; 439/797
137810 Connecting-Posts for Electrical Apparatus, T. Wishart, April 15, 1873, 439/817
140618 Screw-Posts for Electrical Apparatus, S.D. Field, July 8, 1873, 439/810; 256/DIG.3
297655 Binding Post, T.R. Abernethy, Apr 29, 1884, 439/807; 24/459
358518 Binding Post, G. Westinghouse Jr., Mar 1, 1887, 439/812
416288 Binding Post, P.B. Delany, Dec 4, 1889, 439/813; 256/DIG.3
582464 Electric Contact, C.C. Dusenbury, May 11, 1897, 200/507; 256/47; 310/249; 403/218; 439/814


Trimm Headphones with tip
          pinsTip pins were the common connection used for headphones starting for the earliest days.  Later replaced by the 1/4" phone plug.
When a raw wire is connected multiple times it tends to break.  I think the first connectors were ways to have a more durable termination on a single wire.  The Tip pin was the result.
151157 Electric Conducting Cordage, T.L. Reed, May 19, 1874, 439/888 ; 174/124R
    Tip pins formed from heavy wire and the coiled cord.
199827 Tip for Flexable Electrical Conducting Cords, L.E. Heaton, January 29, 1878, 439/866 ; 403/274
203931 Connecting Tip for Electrical Conductors, May 21, 1878, J.A. Nickerson - oldest patent in class 439/805
    but is an improvement using threads to pinch a wire end.
208969 Tips for Switch Cords, T.B. Doolittle, Oct 15, 1878, 439/866 ; 338/332

230090 Tips for Electric Conductors, J.H.C. Watts, Jly 13, 1880, 439/866 ; 439/874
    repairable - prior are used a metal forming method and can not be repaired.
295371 Tip for Electrical Conductors, G. Doolittle, Mar 18, 1884, 439/866; 338/332
317887 Flexible Tip for Conducting Cords, G.K. Thompson, May 12, 1885,
324171 Metal Tipped Electric Cord, W.H. Sawyer, Aug 11, 1885, 439/866
738545 Cord Tip, W. Kaisling, Sep 8, 1903, 439/866 ; 439/623; 439/874
757192 Tip or Terminal for Electrical Wires, S.C. Houghton, April 12, 1904, 439/866

Banana Plug

The Banana plug is a high current single conductor slip fit connector

215917 Attaching Electrical Switch-Wires to Binding-Posts, J.E. Hamilton, May 27, 1879, 439/805
the plug is clearly shown with a slot so that it can be a tight fit into a hole, but no mention is made.
the plug has a cylinder form factor, not a bullet and waist shape.  The begining, but not there.
221074 Electric Conductor, A.A. Knudson, Oct 28, 1879, 439/866 ; 174/110R; 439/825; 439/884; 439/888
    coil spring between plug and wire.  Plug is a split tapered pin.

223969 Electrical-Switch Pin, J.H.C. Watts, Jan 27, 1880, 439/822 ; 379/320; 439/825
split tip with a spring to seperate the two parts, getting close, but no cigar.
2851669 Expansion Type Connector Plug, R.C. Koch, Sep 9, 1958, 439/265 ; 439/551; 439/801
1731661 Electrical Current Tap Plug or Connector, P.A. Hauenstein, Oct 15, 1929, 439/651
2713670 Electrical Jack, Jul 19, 1955, 439/551

1/4" Phone Plug

Commonly available up into the 1960s were 1/4" phone jacks that had one or more switches built into the jack.  For example if you installed a 1/4" jack on a radio that had an internal speaker you could route the hot wire to the switched terminal and it's associated sleeve terminal to ground.  When the plug is installed it would open the switched terminal turning off the speaker.  With the hot speaker wire to the tip the headphones would now work.  By putting a resistive divider between the speaker hot and the tip you could make the max volume in the headphones sort of match the speaker volume, rather than experiencing very loud sound when first connecting.
Headphones with 1/4"
          phone plug
Many of the 1/4" phone plugs were designed to accept Tip pins which were trapped under a screw making it easy to install the plug and not requiring a modification of the headphones.
The 1/4" phone plug was used for telephone and telegraph connections as well as for headphones, microphones, etc.

215568 Telegraph Switch-Board, J.H. Bunnell, May 20, 1879, 361/633 ; 439/675
    uses posts on switchboard and a hollow two conductor plug very similar to the type used on wall warts now.
219936 Coupling for Electric Annlunciator Conductors, H.M. Green, Sep 23, 1879, 200/51.1 ; 439/819
    single conductor, but the right shape plug
411153 Terminal Plug Attachment for Flexible Cords, Sep 17, 1889,
    279/7 ; 279/35; 279/36; 403/290; 411/433; 411/918; 439/805
    jaws grab the wire end and the insulated sleeve clamps the jaws.  This is an improvement.  It's a single conductor.
528529 Plug for Establishing Electrical Connections, C.W. Brown, Nov 6, 1894, 439/750; 439/825
563326 Contact Point for Electrical Instruments, C.E. Scribner, Jul 7, 1896, 439/887; 439/668
886262 Switch Cord Plug, E.L. Smith, Apr 28, 1908, 439/8; 439/460
1584321 Spring Jack, L. G. Pacent, May 11, 1926, 379/328; 439/709; 439/719

Fahnestock Clip

Fahnestock Clips in
          1930s Self Winding Clock Co "Western Union" clockFahnestock Clip can be used with a raw wire or with a tip pin.
photo shows 2 yellow wires soldered to clips in the Self Winding Clock Co. "Western Union" clock.
845268 Spring Terminal-Clip, J. Schade Jr. Assigned to Fahnestock Electric Co, a corp of W. VA, 26 Feg 1907, 439/828
895545 Connecting Device for Electrical Conductors, E. B. Fahnestock, Aug 11, 1908, 439/786; 24/135.00L; 439/828
RE12642 Spring Terminal-Clip, J. Schade Jr. Assigned to Fahnestock Electric Co, a corp of W. VA, Apr 23, 1907, 439/828
Fig 1 is the classic Fahnestock Clip.  
There are about 18 other patents assigned to Fahenstock Electric Co. for very similar clips both made from sheet metal and made from spring wire.
104609 Picture Nail
293862 Cap or Head Covering
1049609 Spring fastening device, John Schade Jr, Fahnestock Electric Company, Jan 7, 1913, 439/828
1163371 Fastening device for electrical conductors, John Schade Jr, Fahnestock Electric Company, Dec 7, 1915, 439/829
1544301 Spring Terminal Clip, A.P. Fahnestock, Jun 30, 1925, 439/828
1622632 Spring Terminal Clip, A.P. Fahnestock, Mar 29, 1927, 439/828; 248/74.2


In 1835 Joseph Henry (Wiki) invented the electromagnet, relay and a side-to-side DC motor, but did not patent any of them since he was a gentleman.

Dual Electromagnet from
          Telegraph SounderNote that the dual coil arrangement on the sounders and relays above, and that on all the stock tickers, except the WU 5-A, district telegraphs,  and on most clock winding or synchronizing electromagnets, bell clapper drivers are all made to the same design prior to about the mid 1930s.  There must have been a huge number of these dual coil electromagnets made.  At the time the electromagnet was common there were not many other electrical components.  The condenser came later.  Resistance was understood and resistors where not named, to add resistance to a circuit you could wind up the length of wire needed or use a rheostat.  Vacuum tubes were not on the scene yet.  So a lot of attention was put on electromagnets and the various ways of making and using them.

It's interesting that my latest Self Winding Clock Co "Western Union" clock (#2) uses a single coil for the synchronizing function where the earlier ones used the same dual coil setup.  The single coil appears larger then either of the dual coils.
4 Jun 2007 - The answer may have come with a Self Winding Clock Co "Western Union" (#2) clock today.  This clock uses a SINGLE coil whereas the earlier clock uses DUAL coils for the synchronizing function.  Looking at the newer larger single coil it's clear that the magnetic path is made up of LAMINATED metal plates, not a single iron piece!  So now searching to learn about laminated cores.  Prior to laminated cores the term used to describe the problem was "Leakage.

1501670 Winding Machine, Henry Koch (Dictograph), Jul 15, 1924, 242/437.4 - Electromagnet Winding Machine
3462091 Cross Wound Coil Winding Machine,

335 Electricity:: Magnetically Operated Switches, Magnets, and Electromagnets
/229 with permanent magnet
/230 Polarized electromagnet
/296 Magnets and Electromagnets.Magnet structure or material
/297 Laminated core

336 Inductor Devices - this class has almost 18,000 patents.
/180 Winding Formed of Plural Coils (Series or Parallel) - most early telegraph, stock ticker, clock coils were actually two series conected coils that were wired to be aiding.
/190 Coil with Crossed Turns.Bank or universal wound coils (e.g., honeycomb, random wound)
/192 Winding with Terminals, Taps, or Coil Conductor end Anchoring Means
/234 Laminated (including wires)
242 Winding, Tensioning, or Guiding
/125.2 Bobbin or Spool.Thread fastener or guide..Strand end attacher...Outer end
29 Metal Working
/605 Method of Mechanical Manfacture.Electrical device making..Electromagnet, transformer or inductor...By winding or coiling
439 Electrical Connectors
/888 Contact Terminal.Having provision for retaining to mating wire (e.g., wire wrap)

Looking for laminated core:
312511 electromagnet 1885 - got better results but they did not understand why 335/220
1511075 Current Limiter - GE - vibrating relay type laminated core oct 7, 1924
1652489 Electromagnetic Device, Dec 1927, Western Electric
1258813 Bell "U" shaped laminated core 1918 - why laminated, easier construction or electrical?
1756672 - Filed Oct 12, 1922
1603832 - Filed May 23, 1923
1629836 - Filed Mar 23, 1923
1550889 - Filed Sep 15, 1924
1548658 - Filed Aug 16, 1921
1546885 - Filed Dec 31, 1923
1565001 - Filed Feb 28, 1921
1607288 - Filed Jun 26, 1923
1881089 - Filed Oct 11, 1929
1644789 - Filed May 17, 1924
RE21116 - Filed Nov 10, 1931
1672193 - Filed Mar 30, 1923 ** valve actuater
2085462 - Filed Jun 13, 1934
1766665 - Filed Aug 31, 1926 ** railroad AC relay
1682364 - Filed Jan 9, 1923 **
2083395 - Filed Aug 14, 1935  **
1897040 - Filed Mar 8, 1932
1815710 - Filed Jun 29, 1929
1765715 - Filed Apr 16, 1923 ** Leakage no
2025093 - Filed Oct 26, 1932
1929787 - Filed Jan 18, 1930
1906496 - Filed May 27, 1930
1878800 - Filed Dec 14, 1931
1720943 - Filed Jul 2, 1927
1834898 - Filed May 21, 1930
1550098 - Filed Mar 15, 1923 door buzzer
1747309 - Filed May 28, 1926  relay
2090918 - Filed Sep 11, 1935
1860820 - Filed Mar 6, 1929
1753726 - Filed Nov 28, 1928
1624536 - Filed Dec 13, 1924
1585811 - Filed Dec 4, 1920  ignition coil
1727848 - Filed Apr 29, 1926
1612726 - Filed Oct 24, 1923  magneto
1631737 - Filed Apr 17, 1922
1543001 - Filed Sep 5, 1923
1768630 - Filed Feb 18, 1925  ??
1599842 - Filed Oct 16, 1924  ignition coil
1772596 - Filed Jul 16, 1923  ELECTRIC RECIPROCATING MOTOR
2133052 - Filed May 3, 1935 ELECTRIC CLOCK synchronous
1965772 - Filed Mar 3, 1932  ELECTRIC CLOCK MOTOR AC synchronous
1674245 - Filed Oct 9, 1923  ELECTRIC BELL
1878606 - Filed Jul 20, 1928  COIL CONSTRUCTION
2063116 - Filed Oct 21, 1933 VIBRATORY ELECTRICAL MOTOR
2048375 - Filed Jul 6, 1935 - Edlson MAGNETO-ELECTRIC GENERATOR
1603872 - Filed Jun 14, 1922 - MILLS NOVELTY COMPANY SANDELL
1616180 - Filed Dec 23, 1921 ELECTBOMAGNETIC JJEVICE
1842595 - Filed Oct 24, 1927 ELECTROMAGNETIC DEVICE
1557621 - Filed Feb 17, 1923 TELEPHONE RECEIVER
1728468 - Filed Jun 18, 1928 BESSEE ADVERTISING DEVICE F
1797912 - Filed Jun 18, 1929  CLOCK
1536279 - Filed May 27, 1920 VINCENT G - laminations common in AC motors
1763007 - Filed Nov 14, 1927 ELECTROMAGNET
1537103 - Filed Jun 15, 1921 FOR ARC LAMPS

32874 Electromagnet, J.S. Jenness, Jul 23, 1861, 29/609; 29/607; 336/234 - bundle of wires for core (see Violet Ray)
102856 Electro-Magnets, H.M. Paine, May 10, 1870, 335/296 ; 336/184; 336/212; 336/225 - laminated
130811 Telegraphic Apparatus, G. Little, August 27, 1872, 361/210 ; 178/77; 335/230; 335/266; 335/276
without the use of a spring or retrictle force - Polar signaling
142486 September 2, 1873, 361/206 ; 178/45; 310/19; 335/230; 335/237
265485 - includes permanent magnet
314041 - paper insulation
512386 Electro Magnet, F.R. McBerty (W.E.), Jan 9, 1894 - responds to AC but not DC
737720 Electromagnet, J. Duncan, (AT&T), September 1, 1903, 336/192 ; 242/125.2; 439/889 - improvement in the terminals
865907  Coil for Electrical Purposes, E.W. Jodery, (GE), September 10, 1907, 336/180 ; 242/125.2; 29/605; 336/190; 336/192; 439/888 - references 486756 (jewlery cleaning is typo, S.B. 486745) and talks about "cops".


When string or yarn is wound as a Cop the resulting cylindrical product looks very much like (if not identical to) what's called a "universal wound coil".
486745 Cop, S.W. Wardwel, (J.R. Leeson), Nov 22, 1892
752732 Slub Detector, S.W. Wardwell, Universal Winding Machine Co., Feb 23, 1904
801941 Controlling Means for Winding-Machines, UWCo, Oct 17, 1905
881211 Winding Machine Mar 10, 1908,
D35423 Cop or Thread Package, S.W. Wardwell, Universal Winding Machine Co., Dec 10, 1901
593756 Machine for Winding Tapering Cops, S.W. Wardwell, Universal Winding Machine Co., Nov 16, 1897,

Telegraph Patents

    1622  Electromagnetic Telegraph, C. Wheatstone & W. F. Cooke, June 10, 1842 340/825.36 ; 178/31; 340/319; 340/815.69; 340/815.78- keept Morse from getting UK patent.
    1647 Telegraph Signs, S. F. B. Morse, June 20, 1840, 178/2R ; 178/17R; 178/70A; 178/86; 178/89; 341/66
This patent is about what signs are used to represent letters and numbers.  "District" numbers reffers to fire districts where a call box would send the district number and the box number.
    4453 Telegraph, S.F.B. Morse, Apr 11, 1846, 178/95 ; 178/74; 178/92 - improved pen recorder
In this patent Morse envisioned a paper tape written on by a pen.  When current is in the line the pen marks the paper and when the current stops the pen lifts leaving a space on the paper, hence the terms Mark and Space.  Telegraph operators who knew Morse code in order to read the paper tapes learned to recognize their station call signs by ear and so did not need to get up and go to the printer in order to know a message was not for their station.  This lead to using a sounder instead of the printed paper, thus simplifying the whole system.
   6420 Telegraph, S.F.B. Morse, May 1, 1849 178/62 ; 205/53; 347/163 - printing register
  60029 this is a wrong number, but maybe similar to a real telegraph patent
662021 Method of Rapidly Transmitting Telegrams, A. Pollak & J. Virag, Nov 20 1900, 178/15 - uses paper tape with 2 rows of holes, optical reader
73774 Repeater, J.H. Bunnell, Jan 28, 1868
653936 Page Printing Telegraph, D. Murray (Postal Telegraph Co), July 17, 1900, 178/16 ; 178/4; 335/92; 83/234; 83/575 - 2 row needle reader
794242 Tape Controlled Telegraphic Transmitting Apparatus, D. Murray, July 11, 1905, 178/17A ; 178/17R - 2 row
103924 Printing Telegraph Instrument Pope & Edison, June 7, 1873, 178/41
159894 Telegraph-Sounder 178/100 J. H. Bunnell, Feb. 16, 1875 - lever Strike screw is directly over center of arch
161739 Transmitter and Receiver for Electric Telegraphs, A.G. Bell, April 6, 1875 , 178/17B ; 178/48; 178/49; 307/140 -
different tone for each circuit on same wire
174465 Telegraphy, A.G. Bell, March 7, 1876, 379/167.01 ; 178/48 - see my Telephone Patents page
215568 Telegraph Switchboard, J.H. Bunnell, May 20, 1879, - Disk on plug with radial groove fits over notch in sheetmetal (NOT 1./4" plug)
226485 Electro-Magnet, J.H. Bunnell, April 13, 1880, 335/230 - adds permanent horseshoe magnet
237808 Telegraphic Key, J.H. Bunnell, 16 Feb, 1881, 178/101 - the lever and trunions are all formed from a single piece of metal.  This is the key design used for all straight keys since 1881.  For example 239723 was issued in April 1881 and shows the complexity of other designs.
240006 Telegraph Sounder, Burke, Apr 12, 1881, 335/274 ; 178/100
241012 Telegraph Sounder, Herndon, May 3, 1881 - No accoustic isolation so no where as good at making noise as the JHB Sounderes
241067 Telegraphic Realy and Repeater, Randall, May 3, 1881
241293 Telegraphic Key, J.H. Bunnell, May 10, 1881 - two pieces of metal joined to form trunions and lever.
244035 Electromagnetic Aparatus, Crane, July 12, 1881 361/206; 178/97; 335/183- relay
245500 Telegraph Relay and Sounder, Howson, Aug 9, 1881, 335/273 ; 178/82B
246717  Telegraphic Sounder, Burke, Sep 6, 1881, 178/98
248089 Telegraph Relay and Sounder, Davis, Oct 11, 1881, 335/274 ; 178/109
251177 Telegraphic Relay, Buell, DEc 20, 1881, 178/118 ; 335/270
354814 Telegraphic Instrument (Key), J. Steiner, Dec 21, 1886, 178/109 ; 178/98
354815 Telegraph Instrument (Sounder), J. Steiner, Dec 21, 1886, 178/109
538816 Telegraphic Sounder J. H. Bunnell, May 7, 1895 178/100 - more sound from weak armature strikes than prior sounders.  This patent includes the idea of a metal resonator plate (the key idea) and the idea of not connecting the coils to the resonator plate (does not seem to have been used).  There are 38 newer sounder patents and 31 older sounder patents.

Telegraph Paper Tape

2653 Jacquard Motion for Loom, E.B. Bigelow, May 30, 1842, 139/60 ; 139/65; 139/79

18149 Punching Paper for Telegraphs, J.P. Humaston, Sep 8, 1857, 234/94 ; 234/117; 234/123; 83/635; 83/686
51464 Punching Paper for Telegrams, M. Lefferts, Dec 12, 1865, 234/113 ; 40/1.5
794242 Tape Controlled Telegraphic Transmitting Apparatus, D. Murray, July 11, 1905, 178/17A ; 178/17R
122098 Improvement in Perforating Machines, F. Anderson, Dec 26, 1871, 234/99 ; 234/121
141775 Perforators for Telegraphs, T.A. Edison, Aug 12, 1873, 234/108
142485 Perforators for Automatic Telegraphs, G. Little, Sep 2, 1873, 234/97 ; 234/127
147312 Perforators for Automatic Telegrapay, T.A. Edison, Feb 10, 1874, 234/127 ; 234/106
151209  Automatic Telegraphy and Perforators Threfor, T.A. Edison, May 26, 1874, 234/106 ; 178/17R - 5x5 alpha numeric characters
153025 Improvement in Machines for Perforating Paper (for Jacquard loom), Jul 14, 1874, 234/85
158158 Perforators for Telegraph Paper, C. Weatstone, 22 Dec 1874 234/106 ; 234/127 UK patents in 1867 (US filed on March 7, 1873)- three finger keys, dot on one side, center sprocket hole, dash on other side.  Second paragraph mentions "in manner analogous to that in the mechanism of a jacquard-loom".

1858511 Automatic Telegraph Keying Head (Wheatstone (Morse) tape reader, F. Kunc (H.O. Boehme Inc.) May 17, 1932, 178/17A ; 234/75
The Weatstone Morse tape has sprocket holes down the center and used two channels, one for dots and the other for dashes.  So looking at a tape you will see a hole on one side or the other (never on both sides at the same sprocket hole) and there will be a sprocket hole with no dot or dash between letters.  Mechanical pins read the holes.
2246655 Tape Splicer (5-level), W. M. Bacon, Jun 24, 1941, 493/381; 156/502; 178/112; 493/390

Also see Pen Register History & KS-3106 on the Gamewell web page.


The readers are for Weatstone Morse tapes.
        Photo-Electric Keying Head, F. Kunc (Boehme Inc),

1844239 Power Transmission, H.O. Boehme, E. Knopp, F. Kunc (H.O. Boehme Inc), Feb 9 1932, 476/48 ; 476/51; 477/15; 477/19; 74/348; 74/745 - machind dwgs
1858511 Automatic Telegraph Keying Head, F. Kunc, E. Knopp (Boehme Inc),  May 17 1932, 178/17A ; 234/75 -
1939215 Photo-Electric Keying Head, F. Kunc (Boehme Inc), Dec 12, 1933, 178/17D ; 178/17R; 235/458 - works with paper tape where the holes are seperated by less than a hole radius. (see Fig 1 above)
2006714 Tape Guide, F. Kunc (H.O. Boehme Inc), Jly 2 1935, 40/342 ; 226/118.4; 226/196.1; 242/615.21 -
2672509 Teletypewriter Frequency Shift, J.H. McCoy (Army), Mar 16, 1954, 375/306 -
3440452 Timing Circuit, G.J. Boehm (ITT), Apr 22 1969, 327/276 ; 327/392 -

Gill Selective Telegraph

There are three closely related product types.  The lock controlled by Morse code, the telegraph (or telephone) selective calling system and a single railway visual signal controller.
Noticet the first 5 patents were issued on the same day.

430606 Magnetic Power Equalizer, W.W. Alexander (Gill-Alexander Electric Mfg Co), Jun 24 1890,
430607 Electro Mechanical Combination Lock, W.W. Alexander (Gill-Alexander Electric Mfg Co), Jun 24 1890,
430608 Electro Mechanical Combination Lock, W.W. Alexander (Gill-Alexander Electric Mfg Co), Jun 24 1890,
430636 Electric-Circuit-Controlling Apparatus, E.R. Gill (Gill-Alexander Electric Mfg Co), Jun 24 1890,
430637 Automatic Signal and Switch Controlling Apparatus and Verfying Mechanism, E.R. Gill (Gill-Alexander Electric Mfg Co), Jun 24 1890,
540620 Electric Circuit, W.W. Alexander (Gill-Alexander Electric Mfg Co), Jun 11 1895,
548282 Electromechanical Lock, W.W. Alexander (Gill-Alexander Electric Mfg Co), Oct 22 1895
557749 Automatic Electric Railway Signal, W.W. Alexander (Gill-Alexander Electric Mfg Co), Apr 7 1896, 246/3 ; 246/123; 246/263 -

Gamewell- See Gamewell Fire Alarm Box

Known for Fire and Police alarm call boxes (Wiki) and systems.  Note that San Francisco (SF Gate), Boston and New York still used call box systems because they continue to work in cases where cell phones fail (9/11).
Firefighters Hall & Museum - Minneapolis - The Fire Alarm Telegraph System -


Teletype Model 20 in operation with close ups of the typewriter type bars
eletype Model 28 in operation with close ups of the type block

Artifax Books -
Landline and Railroad Telegraph Instruments For Sale - photos of many sounders and relays
Using vintage telegraph instruments: Applying power to old sounders. -
Information on Screw Threads - Whitworth 55 deg in 1860, American NC and NF in 1864
The Telegraph Museum - mostly keys
Telegraph-History - nice pages with key developments - Bunnell Telegraphic and Electrical Co. Catalog 11 -
Master Telegraph Instrument Maker and Inventor : George M. Phelps - describes the relation between Phelps, Edison & Western Union
"Telegraph Lore" ! - Patents - Telegraphic Technology index page -
Telegraphic Instruments of Europe by Fons Vanden Berghen his book Classics of communication is out of print.
The Telegraph Office -
Birthplace of the Telegraph - Telegraph -
J.H. Bunnell & Company -
A Brief History of the Morkrum Company - later became Teletype Co.
The Stock Ticker Census - lists a number of different model numbers.
Stock Ticker Co. Reproduction is like the 1875 model $35,000 each
Clauss Studios Stock Ticker Parts Manuals Domes, Pedestals & non working full size models
Thomas A. Edison Papers - Chronology -
Early Technology - Office equipment - Telegraph Instruments -
Exchange Telegraph Co. Ltd  stock ticker, weight driven -
Exchange Telegraph Co. - Patent No 14430 - 1902 - weight driven, manual wind, One of the photos is of the above unit, not the 1902 unit.
This one looks like one of the Universal type.  "C" notch frame, 4 terminals, round wood over cast iron base, printing coils half way above/below base.  Edison type Unison spiral.
Self Winding stock ticker (mis labeled as Edison Ticker) s/n 12642 -
Another self Winding ticker (mis labeled as Edison Ticker)
A Short History of Telegraphy -Part 1, Beginnings - Part 2, Making a Record - Part 3, Start-stop to Date -
Telegraph - The Electromagnetic Telegraph - Teletypewriter -
Paper Tapes and Punched Cards - illustration of Wheatstones Morse tape and 5 level TTY tape.
North American Data Communications Museum -
Distant Writing - A History of the Telegraph Companies in Britain between 1838 and 1868
Engines of Our Ingenuity - transcripts of radio programs similar to the Connection series on TV
Telegraph Sounder clicks out RSS Feeds: - How to Almost build a sounder - There should be an iron strap joining the bottom of the two electromagnets.  The cross section of each part of the magnetic path should be about the same area.  Also it's important to wire the electromagnets so they aid, not buck.
Lords of Lightening - a directory for telegraph researchers

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