... .~ 

REF ID:Al05022 

July' 18. 1924. 

!hi• atatem.ent ls in testimony th~~t we tho undersigned on this date 

conceived· a certain new and novel printing telegraph device by which it is 

poasible to insert a code on tho transmitted message ot that mchi:'le known 

as the !eletype and nanuf'aot.ured by the Aiorkrum. Co. 1 Chica.go, Illionois• 

'fhe device is such that while the line impulses ••till thereby be in code, a 

similar device at tho receiving station will autor.n tico.lly decode the 

:mess~ge and present a legible reproduction of ~he original. 

llith re.i'erenoe to Figure 1, a !i;,letype transmitter is diagrammed in 

phase electrically and lDBCh!'l.nio •lly with a ~•estern Union tranar:ti tter or o.~ 

other form or tape trs.nsmitter. 

lleans are prOV'ided :l'or stepping forward the tape mecha.nism oi additional 

transmitter or trana:li.tters by :meuns oi' some such circuit as d, m, 1, k and n. 

Magnet 18 is a differentially- wo\Uld nagnet the oha.:r&.oteriatio of' which is 

that current of the sa:ne value in both windings sets up ::i core flux in opposition in each pertaining pa.rt of tho core which tencls to neut~lize each 

other a.nd ar:nature 17 remains in neutrr..l posi·tion. Current in one ~1inding or 

the at.her individually will however actuate ama.ture 17. Now while sgnet 

18 'llA:f be directly placed on the '.eeletype Ill\Chine in place of the feletype 

Coils and bear the same relationship to line as in the case or these coils, 

it is the intention of this st~ter.t.9nt to also cover indirect action of this 

differentially wound nagnet, such as action as a relay on the "'J.'eletype Coilsn 

circuit as it now appears, thereby opera.ting the present system rro.'l a local 

circuit. 

Applications in this respect my'V8ry readily be Dl'.de i'or long line work 

by the insertion in t.he line ot sensttive line rebys which in turn operate 

or are operated by tho res11ltant impulses of the device herei-l. doscri1Jed. 

'Under these conditions the line signals rllY ·oe single current. ?11\.ke and break, 

using non-polarized relays, or by the use of a trans1:dtting relay the line 

aij;!lf.1-ls my be polarized and polarized rel ~s used tor reception. 

It is therefore pointed out that tho device lends itself to ~·,ny ot the 

applio~tions of the usu"ll teletype nachine. 

The circuit or Figure 1, will therai'ore show but ono a.pplic~tion of this 

device in -;vhich case a typic:.\l opero.tion :ray be consilered. 

In transmitting letter A (number ono and two elect.rioo.l impulse) with 

a cipher addition fro~~ t.ho tap-3 trs.nsi1-i tter of sny letter l:f (nw.1ber three 

and four impuls'ls, contact, or pin) the line resultant t.hru the di.f.'ferentia.l 

@'pproved for Release bv NSA on 09-12-2013 pursuant to E.O. 135213 

.• ~ 
IS 

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-

REF ID:A105022 

• 

W. iJ. Tm.,ns. 1----, r----~--~:1.~, I 

I 

2, ,~ . 

I I 

, . 

I 

I 

. :u. I IQ i 

I r 1 I 

----;--1--

1 I /( 

I ---

1 

I 

:t 

I I I 

I 1 I IL_ ________ : 

I 

~/8 jm ----------· 

.+ 

! L, 

,:~ .~· ""; 

• 

J 

,., 

,AfC,.... ~(;':Z .. .... -
•'· 

coil will bo soon to be 

( l 2 3 4 6 

'fra,nsmi t. t.ing ( + + 0 0 0 

(oo++o 

++++o 

REF ID:A105022 

-2- J 

!oletypo tmnond.tM.ne; A 

Tapn ciph<Jr n N 

Lino rosult:.a.nt. K 

How i't. will be understood tha.t. 1\ similar dovico wH.h idon·t.ical ci pbo1• 

t:l.po ia to bo considered a.t the recoivinf~ rm<l of' tho line. 

(12845 

Reoeivinp.: ( -t-+++ 0 I.4.ne K 

( 0 0 -t-+ 0 _ 'l'a.pe ciy.1her H 

++ 0 0 0 Resul t'.1.nt A 

Witnessed ~ II . ;· ·· · /""/ i: I.'· l f (_ • £ {;. ,., ,/ ~ I I 

............ ,,,,;~~::;;:. 

·-'i;~:: ~ 
() REF ID:Al05022() 

-2-

coil will be seen to be 

(12345 

'fransmi tting ( + + 0 0 0 

(oo+-to 

++++o 

Te le type transmitting A. 

Tape cipher " "N 

Line resultant K 

Now it will b1::i understood th.at a similar davice with identical cipher 

ta:pe is to be considered at the receiving end of the line. 

( 1 2 0 4 5 

Receiving ( i" + +·+ 0 

(oo++o 

++ooo 

- - _-.1_____ __ -

Line 

Tape cipher 

Resultan'~ 

....... 

K 

N 

A 

SignedfY:d~ 

-- = 

I 

_, 1 
TELETYPE TRANS. 

RE:e" ID:A105022 ~.J , 

~- .l 

·-------1 

-===-==::. ~ : 

o I • D I L F1 i ---t--+-1 

II ,L ______ J 

I 

I 

I ...._ ___ _J 

--
·-i 

-=- -

1111.----_J. 

A 

RV~·!D.: Al 05022 

t#~· . 

thlt---__J 

---1 ~-·------,-----··-· 

B