Historical Document · 1953
Teletype Model 28 Prototype Info — 1953
Early/prototype 28 apparatus. 71 pp. Not read in detail for this dive
Historical Document · 1953
Early/prototype 28 apparatus. 71 pp. Not read in detail for this dive
0 E-t ::::> CJ) z E-t H ~ < ~ ~ < ~ 0:: (0 < 0:: 0 N < ~ 0:: ~ 0 ~ 0 c.:> 0 ~ ~ E-t X ~ ~ ...:I ~ ~ E-t E-t ~ ~ ~ f-4 INDEX ( ( I Model 28 Plan II Page Printer Ill Keyboard IV Page Printer Cabinet and Covers y Page Printer and K~ard Accessories VI Transad.ttetf Distributor Sets A. Single Message B. Multiple Arrangement - 3 Message c. Multiple Arrangement - 6 Message VII Reperforator Sets - Receiving ~ A. Nontyping B. Typing c. Multiple Arrangement - Nontyping D. Multiple Arrangement - Typing VIII Ke,board Operated Tape Sets A. Keyboard Perforator- Nontyping B. Keyboard Perforator - Typing c. Tape Printer D. Typing Reperforator E. Typing Reperforator - equipped with tree keyboard IX Tape Sending Sets A. With Nontyping Keyboard Perforator B. With Typing Keyboard Perforator c. With Send-Receive Typing Repertorator D. With Send-Receive Typing Reperforator equipped with free keyboard X Tape Sendin~ Set With Send-Receive Page Printer A. Without Typing Reperforator Feature B. With Typing Reperforator Feature • ( MODEL APPARATUS 28 PLAN Model 28 is a designation applied to a complete new line of Teletype apparatus. This·is a carefully planned line of telegraph apparatus units·built around five basic machine components. The five components and the general plan for combining them are shown in the diagram which follows. ( THE 28 PLAN BASIC UNITS r··~ ( TAPE PTR. PAGE PTR. CLLJD TI2ANS. DIST f2EPERF KEYBOARD REPRESENTATIVE COMBINATIONS COMPLETE SET ( [M -1 2EPERF Tr2ANS. [- -r 01 I KEYBOA~D PE 12F. If J· CJ SEND-f<EC. PTR. DESIGN OBJECTIVES OF THE MODEL 28 LINE ( To meet the increasingly complex requirements of printing telegraph conmrunication in an efficient and economical manner, it became evident that a new line of equipment was needed that would fulfill the following prime objectives: 1. Less maintenance. 2. Quieter operation 3. Increased speed. 4. Lighter weight. 5. Smaller size 6. A complete line of apparatus units employing standardized basic components in various combinations. 7. Common mechanisms and parts wherever practicable. 8. Expanded capacity for special functionso 9. Greater shock resistance. ( ' ;, 10. Stability of operation in non-horizontal positions and under conditions of severe vibration. II PAGE PRINTER In the design of the new page printer, a survey showed the need for a wholly fresh approach. It was obvious that the requirements could not be met with an assemblage of modifications and adaptations of existing mechanisms. For example, a review of the typing mechanisms used in previous Teletype units and in equipment developed by others indicated that they are generally unsuited to meet the new requirements. ( Older clutch designs are especially inadequate. Felt clutches require frequent servicing due to heat and loss ot lubricant; positive clutches are subject to variable engagement. Type Box Printing Ot the innovations in the Model 28 printer, probably the most striking is the printing mechanism. Type pallets, instead ot being mounted on conventional type bars, are carried in a snail rectangular box about l" thick, 1" wide, and 2 11 long. Pallets are arranged in four horizontal rows, each row having a capacity of 16 characters. Letters are in the lett halt ot the box, figures in the right half. To print, the type box is moved to bring the desired character to the printing position, and a printing hammer drives the pallet against the ribbon and paper. After each stroke, the type box is returned to its normal position below the printed line so the typed matter becomes visible. Advantages: ( 1. T,ype alignment is controlled by manufacture of parts; no further adjustment required. 2. Type box is removable with a light finger motion; no tools required. Facilitates cleaning, as well as change to other characters (e.g., weather s,ymbols). 3. Weight of carriage assembly reduced to 8 oz. (compared to 5 lbs. on Model 15). 4. Made possible reduction in over-all size and weight of machine. 5. Made possible use of stamped sheet metal framing instead of cast framework, permitting further reduction in weight of machine. ·dn., .zedwd ..tnn.rn).xo uv t{'l'Pl uosl.xwdmoO> ~l tutoqs IOEI idlJ. IDIJ. ~ 9J:nil4 "t\\1.. ?i.RI'QR""l\Ci. l)"'t" Figure 3 When the type-box is in the desired position, the printing hammer drives the type pallet against the ribbon an:i paper. ------- -~--#""" Figure 4 A comparison ot the new type-box with the older "basket" carriage. The new type-box assembly weighs only 1/loth as much as the older moving carriage. II# I -"" ' ~ 6. Carriage return is very fast, with negligible power input. 7. Gravity has no significant effect on carriage motion. 8. Shift and unshift are accomplished with type box; platen remains stationary. Simplifies paper handling, improves readability. 9. Since each character is separately mounted (instead of a type pallet carrying two characters, as in conventional machines), overscoring and underscoring are eliminated. 10. Because the same hammer blow is applied to all characters, printing impression is more unifo:nn. This is especially important in multiple copy work. ( Ribbon Mechanism The ribbon spools are mounted on the machine itself, rather than on the type carriage. Provides a strai~ht course .for the ribbon travel. Facilitates changing of ribbons. Cuts down number of guides required. Also, in combination with the more gentle blow of the new type hammer., resul.te in increased ribbon life. All Steel Friction Clutch (Fig. 5) Another striking innovation is the new clutch. It is an all steel, internal expansion friction clutch which disengages in the stopped condition. Older clutches depend upon slippage between felt washers and steel plates when a stop is interposed, so that the driven member is mechanically held from turning. ( Clutches of the new design are used not only for driving the selector cams, but for the various other power actions--moving the type box, feeding the paper, spacing, etc. The new type clutches are used throughout the Model 28 line. Advantages: 1. Eliminates need for frequent clutch lubrication; requires oiling only once or twice a year. 2. Lengthens lubrication interval for printer: 60 speed - 3000 hours operation 100 speed - 1500 hours operation 3. Has exceptional stability. adjustment. No need for frequent torque )~ ~. DIRECTION OF ROTATION DIRECTION OF ROTATION ~ ~ ~ LUGON ~,--CLUTCH DISK DRUM-...,,,, ~~ ~/ ~---~h........ I .! ~ '\ 'I~ ~· \ ~ (a) CLUTCH DISENGAGED /II~ I SECONDARY SHOE ,/ CLUTCH SHOE ~ LEVER ~ (b) CLUTCH ENGAGED Fig. 5- The clutch used on the Model28 teletypewriter is an internal expansion friction clutch. Selector (Fig. 6) The selector has only two adjustments. When adjustment is made in accordance with the spec1tication, correct operation with proper margins is bmediately obtained. The magnet armature is unusually smll and light, with a very short travel. This provides high speed operation with low power input. •Stunt Box" (Fig. 7) ( In recent years, there has been a growing need .Cor a simpl.e means o.r handling-vi.thou.t the sacrifice of key characters-an everincreasing nUJIIber o.r nontyping tasks, such as station selection, remote control, suppression o.r typing and spacing, etc. In the Model 28 printer, all nontyping oper:.,t:ions are controlled by a unique "stunt box". Extending across thu full w.i.dth o.r the typing unit, it has 42 slots. Each slot can hold a fUnction bar capable o.r responding to an assigned code. Ten positions are reserved .Cor the co111110n tunctio~carr1age return, line teed, shift., etc. Thirty-tvo positions are available .Cor •special assignments". This, in effect, expands the telegraph alphabet, since the DU.lllber of possible code combinations is large. Power-Driven Code Bar Selection (, The code bars (which are the indexing mechanism trom vtd..cb the type box obtains its positioning information) are driven by direct motor power to ei. ther the marking or spacing position. This overcomes effects of gravity and the drag of thick lubricants tmder low temperature conditions. Positive drives are extensively used throughout the printer for this same reason. Paper Feed A separate clutch is used tor line feed. Permits 11 power11 .reed-out of paper and eliudnates need for exposed platen crank. An improved paper strai~htener mechanism provides constant operation under adverse conditions without paper jamming. ~ c:t: 0 ~ (J) ~ a I'<. ..... ~ 10 ~ ~ ~ ...., ~ cd "0 i ~ i Q) 10 .....s.. G) g. c:t: •18q'lt{dtv qdv.x~ete'l &t{'l spu~ uXOO .tNfl.tS 11 :m.L L e.~~y •. III. THE KEYBOARD The Model 28 is equipped with a pcr11er keyboard. It bas a "universal" keystroke-uniform for all keys. The touch is light and shallow. ( The keys are modern, completely redesiP,Ded. Spacing between keys is the same as on standard typewriters. An extra row or keys bas been added for local. control or runctions such as carriage return, line feed, etc. Included are loca1 lock and unlock keys to prevent accidental depression or a ke.ylever. The keyboard is sealed against dust. Signal Generator In place ot the six-contact signal generator used on older mchines, the Model 28 is equipped wi tb a single contact signal_ generator mechanically operated by the distributor. Advantages: ( 1. No adjustment is ever required, other than poldtioning the assembly itself. 2. Has the form of a transfer switch.. Permits either open or closed signal transmission, or transmission of signals or alternate polarity. The signal generator is mounted in a metal box for prot;ection and shielding against radio interf'erence. Signal ~enerators of the new type are used throughout the Model 28 line. Improved §ynchronous Motor f The s.ynchronous motor is especially designed for long life. The ball bearings are greatly oversize to minimize bearing trouble. The starting switch has been eliminated by the use of a rugged external starting relay so the service man has no need to open the motor. An improved internal air circulating system rapidly takes heat out of the motor and an external fan circulates the warm air along the machine cover surface so that heat is quickly dissipated from the machine without the need for external air circulation. This helps to keep noise in and dirt out. Rubber mountings are provided to minimize motor noise. Governed Motor A universal AC/DC governed motor provides long periods of trouble-free service. The governor has a life of 3000 hours without attention. This is approximately equal to the life of the motor brushes and matches the extended service period for the rest of the machine. \, The governed motor operates at 36oo RPM, which is the speed of the 60 cycle s.ynchronous motor, and therefore, uses the same gears. The two motors are mechanically interchangeable. IV. PAGE PRINTER CABINEI'S AND COVERS Cabinet (Fig. 8) The cabinet was designed with the following objectives in mind: ( 1. Operating convenience 2. Accessibility for servicing and maintenance 3. Suppression of noise 4. Good appearance All mechanical controls have been brought to the front. The manual platen crank has been eliminated and replaced with a rapid motor-driven feed-out controlled by a button on the keyboard. A lamp within the cabinet illuminates the copy. The angle of the window above the copy has been chosen so that glare is practically eliminated. The upper section of the cabinet swings open to provide access for insertion of paper and ribbons and for maintenance. The entire page printer keyboard set is mounted on a cradle so that the set can be pivoted forward for access on all sides. It desired, the operating portions of the set can be removed from the cabinet and the lower front tray shown pivoted forward in the photograph (Fig. 8) can be slipped horizontally into the upper portion of the cabinet to provide a working surface for servicing. ( Electrical accessories, such as the line relay, motor control relay, rectifier, etc., have been placed in a box behind the typing unit. Except for a narrow paper exit slot, the cabinet is entirely sealed to suppress noise; keep out dust. Cabinets may be fastened together in rows to conserve floor space. ( Cover - Table Model A light-weight, low-cost cover tor rack or table mounting; close fitting-takes up a mi.nimwn amount of space. possible: Includes as many or the features ot the cabinet design as 1. All mechanical controls on front ot cover, including motor-driven teed-out. 2. Copy lamp inside cover • .3. Non-glare copy window. 4. Electrical accessories mounted in box behind typing unit. 5. Easy access tor changing or paper and ribbons. 6. Sealed to keep dirt out and cut down noise. ( ilJt~tmOH etct'BJ, ~o l{O'BU .JOo!l lm.LN:rnd :liDVd sz rma<Ji itq ~unOH etqVJ, .10 lf:>VH .104 HiJ.NIHd mlYd 8Z 'mOOK ( Cover - Command Aircraft Model This is an early version of the table model. Several Model 28 printers housed in these covers have been installed in command aircraft. ( OYS-1J"8.lo.llV pnaiiiOO 11J 'P8ttV1SUl mLIJmld if>Yd ~ 'DIQ(J( OYS--1.J'I.I:).llY PU'IIIIIIOO 1ll J'et'!W18UI liiJJm!d IDYd at 'l!aCII I I Cover - Advance Base Hodel A light-weight, close-fitting cover especially designed for use at advanced ai~ bases. Fits in immersion-proof carr,ying case. ( Weights and dimensions of the Model 28 Advance Base Printer and auxiliar,y equipment are as follows: Weie;ht 18.5 lbs. 19.5 lbs. 8.0 lbs. Page Printer Keyboard with Motor Cover Total 3.0 lbs. 14.0 lbs. 53.0 lba. Electrical Service Unit *Immersion-proof cover Chest Over-all Dimensions Printer and Cover *Immersion-proof Cover 1;0~0 lbs. Width Height Depth 1711 12" 13" 19" 25 11 19" *Immersion-proof cover contains electrical service unit as well as printer. Complete advance base printer equipment may be transported in one package. \ ~·~d aivd ~ t•pow aeva eouaApy - iSYO f>NllmrtO .iOOHd NOismiHWI !SVQ iONVAOV - H:!I:J.NI'Hd iDVd 8l 'mOOH V. PAGE PRINTER AND KEYBOARD ACCESSORIES The Model 28 plan provides for a full range of accessories needed in printing telegraph communications and for a large variety of conveniences for operators and maintenance personnel. Many of these optional features are in process of development, and a number of the more important ones are currently available. ( Among the accessories on which development is well advanced are the following: Page Printer station Selector System A telegraph selective calling system. Delay Motor Stop Mechanism To shut motor off after idle line time of a predetermined length. Ti~e Electrical Motor Stop Mechanism To shut motor off remotely upon receipt of the proper sequence of characters. Automatic Carriage Return-Line Feed Sprocket Feed Platen Will feed up to twelve copies interleaved with one-time carbon. Horizontal Tabulator With automatic cut-out ot transmitter distributor during tabulation. ( Form Starter Upon receipt of the proper character sequence, this mechanism will cause the platen power drive to feed the paper up to the desired starting position at the head of the next form. Also useful in communications to give uniform paper size to messages, simplit,ying their handling and filing. Reperforator Control To control an auxiliary tape reperforator. Local Reverse Line Feed, motor-driven On Line Back Space This mechanism, together with Reverse Line Feed, will enable the operator to bring previously typed material back for correction. Permits the printer to double as a typewriter where space and/or weight considerations make a dual-purpose instrument desirable. ( Keyboard Off-Normal Contact A contact operating during the keyboard signal generating cycle to condition a radio transceiver for transmission. Repeat-on-Space Mechanism To allow the space signal to be repeated while the space bar is held depressed. Cabinet Offset Cop,yholder Form Accumulator Shelf For continuous form papers. Form Paper Supply Box Accessor.r Mounting Relay Rack ( Electrical Line Relay, with mounting D.C. Power Package To permit operation on direct current power. Radio Interference Suppression Filters. - MODEL 28 PAGE PRINTER with horizontal tabulator VI. A. TRANSI{ITTER DISTRIBUTOR SETS Sin3le Message This transmitter distributor was developed as a component or the Model 28 line, to meet the need for a simple, low cost~ baaic tape reader. In keeping with the overall objectives or the Model 28 program, emphasis was placed on reliability or operation, compactness, minimum weight and minimum maintenance requirements. General Operating Features: ( 1. Uses motor, clutch and signal generator of the same type as the page printer. 2. Speeds up to 200 wpm are available • .3. Tape is advanced by a unique feed wheel. The tape is engaged by 7 feed pins on this wheel, which hold the tape securely and keep tape feeding problems to a minimum. 4. Tape-out Mechanism. The unit shuts ott when a sixth pin senses the absence of tape at the end ot transmission. 5. Motor ON-OFF switch. 6. Tape lid release button. 7. ( Three-position transmitter control. Unit may be put in running position, or one of two stop positions: (a) with feed wheel held from rotating so tape position is not lost; (b) with feed wheel free to rotate so tapes may be inserted into transmitter (as in torn-tape switching applications) without the necessity of lifting the tape lid. Accessories: 1. Tight and tangled tape stop. For applications where the transmitter distributor is to be used next to a perforator. When the transmitter distributor has absorbed the tape loop, tension in the tape will raise the stop arm, sh'l.ltting off the unit. stop arm w:Ul also lift i f tangled tape should try to enter the lid. 2. Torn feed hole tape stop mechanism. If tape is not being properly fed by the feed wheel because or torn feed holes, this device will auto~~tically stop the transmitter, N 0 0 .l 319NIS) (39VSS3V'J d CJOl_n81cLlSIO 0 CJ3l_l_IV'JSNVCJ1_ 82 1300V'J 3 d A .l 3 I .l 3. Bell on 11 Blank 11 • Trancnrl.ts 11 Bln.nl: 11 (nonrcp(;~a.t) lrl.thout affecting tap~ in unit. For audible signaling purposes. Used primarily in railroad applications. 4. Multi-wire output. For cross-office switching, where it is desired to transmit at high speed. Also convenient for operating relays which act as control circuits for transmitters sending without benefit of a monitoring page printer. 5. Remote space block. Stops feeding and repeats character previously sensed. 6. Break lock. Should signal line open, this mechanism ( will stop the transmitter so message will not be transmitted into the open line. It can be arranged to sound an alarm bell. 7. Stop on 11 Blank11 • Stops the transndtter when a "Blank" combination appears in the tape. 8. Tape deflector. For use in connection with multiple address messages in a torn-tape relay s,ystem. Deflects tape to front or unit instead or permitting it to go to discard. B. Multiple Arrangement - Three Message Three transmitter distributors, gang mounted, driven b7 a single motor. C. Multiple Arrangement - Six Message Six transmitter distributors, gang mounted, driven b7 a single motor. Available in two arrangements: ( 1. A single row of six transmitters. 2. A "terraced" arrangement, with three transmitters in the lower row and three in the upper row. The motor is mounted to the rear of the lower row; the upper row is offset for operating convenience. The back of the unit is flush. A compact, space-saving arrangement. Cari be element of tom-tape transmitter bay. ei'I888H ( - ~ua•iuv.uy •tdl~tnH liO.tOQIHJSia mi.LJ.IKSNVHJ. 8Z 'maetl TELETYPE CO RPO RAT MODEL 28 TRANSMITTER DISTRIBUTOR- MULTIPLE ARRANGEMENT 0 (3 MESSAGE) N ei'88sew 9 - ~ue111eiuvuy •tdl~ll\H HOJJlQD:IJSia EiJJ.IWSNWJ, ~ 'l!GOW TELETYPE COR PO RAT MODEL 28 TRANSMITTER DISTRIBUTOR-MULTIPLE ARRANGEMENT (6 0 MESSAGE) N TELETYPE COR PO RAT 0 N MODEL 28 TRANSMITTER DISTRIBUTOR- MULTIPLE ARRANGEMENT (6 MESSAGE) VII. REPERFORATOR SETS - RECEIVE-ONLY As part of the Model 28 line, entirely new components have been developed for perforating tape and typing on tape. These units have been designated as the Tape Punch and the Tape Printer. The Punch Unit ( A weak point ot older punching mechanisms is the teed pin of the punch block, which must participate in every cycle of operation. The new Punch uses a tape teed wheel tor a roll-in type of teed hole, distributing the wear over 24 feed pins. The Model 28 Punch perforates a square, chadlesa code hole, which greatly reduces the force required to perforate tape, and consequently the strain on the entire mechanism and on the motor. These two major innovations, together with a number of minor improvements, have resulted in a Punch Unit which represents an important advance over older means for punching tape. Advantages: 1. Laboratory tests show it has double the lite of pr.evioua punch units. 2. Eliminates expensive die blocks. 3. Contains a large number of common and interchangeable parts. 4. Simplifies and cuts down maintenance: (a) Lubrication intervals are extended (b) Assembly and disassembly are simpler (c) Accessibility for adjustment is improved ( 5. As a by-product or the use ot the tape feed wheel, the threading of tape has been made ~ch easier; simple tape insertion with a twist of' the tape teed wheel knob threads the unit. The Tape Printer Built primarily as an adjunct to the punch unit, the small typing mechanism incorporates a readily interchangeable plastic type wheel. Character sizes and fractions up to 0.200" are permitted. The last character printed is visible to the operator. The unit uses a standard typewriter ri.bbon, which can be readily changed by an untrained operator. A small hammer delivers an adjustable blow to the underside of the tape to type the character impression. A. Nontyping Reperforator Combining the Punch Unit with the Selector, Motor Unit, and the proper gears produces a simple, reliable and compact Nontyping Reperforator. All metal clutches are used. Speeds from 60 w.p.m. to 200 w.p.m. are available. ( The Reperforator is capable of handling up to a ?-element code on tapes as wide as 7/8 11 , although it is usually arranged for the standard 11/16 11 tape. Extensive use is made of simple harmonic motion principles, and the absence of felt clutches results in long lubrication intervals. B. Typing Reperforator Since the Model 28 tape typing mechanism was designed as a complement to the Punch unit, a single-unit Nontyping Reperforator may be easily upP,raded to a Typing Reperforator by the simple addition of the tape typing mechanism. Printing occurs on the 11/16 11 wide tape directly over the chad perforations, six characters behind the punching point. This six-character lag was chosen to match equipment now in use. The Typing Reperforator is capable of speeds from 60 w.p.m. to 150 w.p.m. ( C. Nontyping Reperforator - Multiple Arrangement The Model 28 Selector and Punch Unit have been designed to fit into a very narrow space. The selector push bars have been arranged to coincide exactly with the punch fingers so that an extremely simple transfer mechanism will carry the received signal permutation directly to the punch fingers. This simplicity permits four Nontypin~ Reperforators, driven by a sin~le motor, to be mounted abreast in the shelf of the standard Teletype Universal Cabinet. N 0 .l 0 d 9NidAl.- CjQ_LVCjQ..:JCj3d3Cj 0 d A 82 l300V\J .l 3 l 3 .l l MODEL 28 REPERFORATORS - TYPING and NONTYPING Multiple Arrangement - In Universal Cabinet D. 17Ping Reperforator - Multip1e Arrangement Here, again, the compactness of design of Model. 28 components makes it possible to concentrate considerable equipment in SDBll apace. Either two or three (as desired.) Typing Repertoratora •7 be mounted abreast in the Teletype Universal Cabinet. Driving these units from one motor makes available a simple receiv.lng group for a Torn-Tape switching center. Ot course, it is not necessary that all units of a Jailtiple arrangement be either typing or nontyping. An acCOIIIp6JV'ing Ulustration shows one Typing Repertorator used with two Nontyping Repertorators in a Teletype Universal Cabinet. ( Accessories for Reperforators Fol.lowing is a list of the more important optional accessories available tor Repertorators: 1. Backspace mechanism. 2. Non-inter.tering tape feed-out. Automatical.ly' at the end ot a message, or manually at the push of a button, thia mechanism will cause a predetermined length of tape to be .ted out. Should a message start coming in while tape ia being ted out, the mechanism is so designed that tape · feeding will stop 111111!ed.iately and the measage will be recorded without loss of even the .Cirst character. 3. Code reading contacts. These contacts close and Opal in accordance with the received characters, proriding a t ive-wire e1ectrical signal to be used tor control purposes. ( 4. Low Tape alarm 5. Torn Tape alarm 6. Tape noteher. Permits notching of the side of the tape to cause the Transmitter Distributor tape-out pin to stop autoEtic tranamission at a predetermined point-. This feature is used predominantly with keyboard units. VIII. KEYBOARD OPERATED TAPE SETS As a result of the careful planning which has gone into the Model 28 line, a~wide variety of keyboard-based tape printing, tape perforating and tape reperforating apparatus becomes available. Basic components and mechanisms are put together in various combinations to obtain multiple-purpose equipment of exceptional versatility and co~ pactness. The high percentage of common components, mechanisms and parts yields a further dividend simplifying maintenance and reducing problems connected with repair parts inventor,r. ( For perforating, the keyboard becomes a free-speed instrument. The top speed of 150 Words a minute is far higher than an operator can normally type. However, to provide for speed bursts between readily typed character combinations -- such as "ER" or ''TH" -an overlap feature has been built into all Model 28 keyboards. This permits depression of the succeeding keylever before the cycle actuated by the preceding keylever has been completed. An instantaneous speed of 1,440 o.p.m. between any two successive characters is available. A. Keyboard Perforator - Nontyping The successor to the standard Teletype tape Perforator (GPE), used to prepare a perforated tape for transmission over a signal line by a transmitter distributor. Consists of: Model 28 Punch Model 28 Keyboard General Operating Features: 1. ( Free keyboard 2. Tape back space 3. LTRS erase Accessories: 1. Tape notcher, to stop transmission at predetermined point. Notch in tape will be sensed by the tape-out mechanism of the transmitter distributor. 2. Linear scaled character counter. Since it is difficult for the operator to tell when a complete page line has been typed, this convenient character counter has been provided to give a visual indication of the typing position. Counter can be read at a glance while operator is viewing copy. Line light flashes on at an adjustable distance before the end of the line to warn the operator. For low-cost installations the end-of-line indicator is available without the counter scale. B. Keyboard Perforator - Typing This is a new combination, making possible oft-line preparation of chadless tape with typing ori the tape. (' Consists ot: Model 28 Punch Model 28 Keyboard Model 28 Tape·Printer Optional Equipment: Character Counter Same as Nontyping Keyboard Perforator except that tape printer has been added. c. Keyboard Tape Printer The successor to the Model: 14 Tape Printer, used tor telegraph transmission on printed tape, gummed or ungwmmed. Consists of: Model 28 Ke,yboard Model 28 Tape Printer Model 28 Selector Model 28 Signal Generator Optional Equipment: Character Counter ( D. Typing Reperforator The successor to the Model 14 Send-Receive Typing Reperforator, combining facilities for interchange .of messages and tor receiving tape for relaying purposes. Consists of: Model 28 Punch Model 28 Keyboard Model 28 Tape Printer Model 28 Selector Model 28 Signal Generator Optional Equipment: Ch~racter Counter E. Tzping Reperforator with Free Keyboard Qption Same as Typing Reperforator previously discussed, except keyboard arranged for optional free-speed operation, tor off-line preparation of tape at high speed ( (, DNidlJ. - liOJ.WO.!lmld ClliVOOID 8?! 'liGON N 0 l. 0 d 9NidAj_- CJOj_V'CJO..:lCl3d 0 3 OCJV'08A3'>-I d A l. 3 82 l300V'J l 3 l. N 0 .l 0 ~Ol.'v'~O.:I~3d3~ d £>NidAl. 3 0 3/\13:::>3~- ON3S d A l. 3 8Z l300V'4 I 3 .l IX. l TAPE SENDING SEI'S These sets combine .the facilities of the keyboard-operated tape sets with the transmitter distributor. A. Tape Sending Set with NontyPing Keyboard Perforator Same components as Nontyping Keyboard Perforator, with transmitter distributor added. Consists of: Model 28 Punch Model 28 Keyboard Model 28 Transmitter Distributor B. Tape Sending Set with Typing Keyboard Perforator Same components as Typing Keyboard Perforator, with tranemitter distributor added. Combines for the first time a free key-board typing perforator with a transmitter distributor to to~ a compact message originating station for the inexperienced operator Consists of: ( Model 28 Punch Model 28 Keyboard Model 28 Tape Printer Model 28 Transmitter Distributor N 0 CIO.l'v'CIO.:ICI3d OCI'v'08A3>-I 'JNidA..L H..LIM .l3S 'JNIO N3S 3d'v'.l 82 l300V'J .l 0 d 0 3 d A .1 3 'l 3 .l t'' c. Tape Sending Set with Send-Receive Typing Reperforator Same components as Send-Receive Typing Reperforator, with transmitter distributor added. The equivalent o! the TG-26 set. Cons! at s ot: ( Model 28 Punch Model 28 Keyboard Model 28 Tape Printer Model 28 Selector Model 28 Signal Generator Model 28 Transmitter Distributor (~-~'P'I»e 9t-DJ.) .10'4V.ZO;adeH ltzlci4 8A"f8:Mtll-J)U8S Q~l~ m f)Kim«s ldY.t. ez 'l!a<Jf TELETYPE COR PO RAT MODEL 28 TAPE SENDING SET WITH SEND-RECEIVE TYPING REPERFORATOR 0 N ( D. Tape Sending Set with Send-Receive TyPing Repertorator and Free Keyboard Option Same components as preceding set 1 except keyboard arranged for optional free-speed operation, tor ott-line preparation of tape at high speed. Choice between on-line and high-speed ott-line operation is made by a simple flick of' a switch. This unique set is the logical extension of the tacilities offered in the TG-26 set. ( p.noql•J 8N.i ~0~ peddll\bl ~O'lV.ZOlo!ed8H iUldAJ, U'J808li-PU8S q~lA .I.IS DHICIKiiS !dV.t 8Z 'maOH ( X. TAPE SENDING SET WITH SEND-RECEIVE PAGE PRINTER While the Tape Sending Set with Send-Receive Page Printer is the most versatile unit in the Model 28 line, its primary function is to serve as a high-capacity message originating station. Made up ot basic mechanisms previoual7 introduced, the set will do everything the popular Modell9 Set has so long done, and more. By means of a control lever, the operator can select any one of the following three operating conditions: ( 1. Keyboard Position -- The keyboarded message is sent directly to the distant receiver while the Page Printer provides a local copy. 2. Keyboard and Tape Position -- Tape is produced as a by-product ot the on-line keyboarding operation. 3. Tape Position - A tape is produced by the keyboard operator. Here the operator is not tied down to the signal line rhythm and can type at top speed on a tree keyboard. Normally the tape coming from the Perforator is inserted into the Transmitter Distributor and automatically transmitted, with a local copy ot the message being made on the Page Printer. ( A. Tape Sending Set with Send-Receive Page Printer -without ~ Reperforator Feature Consists of: Keyboard Tape Perforator, with Signal Generator Page Printer, mounted above the Ke,yboard Perforator Transmitter Distributor, mounted to the lett ot the tape exit point ot the Keyboard Perforator. t MODEL 28 TAPE SENDING SET With Send-Receive Page Printer (EquiY&lent of Model 19) B. ( Tape Sending Set with Send-Receive Page Printer - with Typing Reperforator Feature on Keyboard Perforator (a) The versatility of the set previously described can be further extended by adding either or both of the following components: 1. A Tape Printer can be added to the Punching Unit ot the Keyboard Perforator, so that messages w:lll appear in typed form on the tape. 2. A Receiving Selector can be mounted to the right of the Punching Unit of the Keyboard Perforator eo that the Punch Unit can be used as an auxiliary tape receiver when the set is in the keyboard position. Addition of the Tape Printer in no way interferes with the extremely high rate of speed of which the free keyboard is capable. Adding the Selector affords an inexpensive reperforator feature, useful for tape relay work, tape reproduction or correction, etc. ( MODEL 28 TAPE SENDING SET TfiiTH SEND-RECEIVE PAGE PRINTER Provides typing on the perforated tape. Equipped with receiving selector on punch. ,. (. . C.; Tape Sending Set with Send-Receive Page Printer With Self-Contained AuxiliarY Typing Reperforator Where simultaneous keyboard perforation and reperforated tape reception from a distant sending station are desired, facilities are available to mount a completely self-contained auxiliary typing reperforator on the lett-hand shelt ot the console, behind the transmitter distributor. The reperforator feature on the keyboard perforator described under 11 B11 above might or might not be desired in this case, depending upon the amount of relay and tape reproduction work handled by the station. ( ( D. Accessories A full range of accessories and optional features are contemplated for these sets. In addition to those applicable to the Page Printer, the Keyboard, the Transmitter Distributor and the Typing Reperforator, a number of special accessories will be provided, among which are: Character Counter with End-of-Line Indicator Light Large Pull-out Relay Rack For installation of a wide variety of electric or electronic line terminating gear. Offset Copyholder An 8!" x 11 11 tray to receive local copies of messages transmitted. \, ~9~Ul~d 9~Vd Q~1M ~alliWSNVHl-HOlVH~d crHVQ8lg] az 1aOOW