INPUT MANUFACTURE JANUARY 1965 DISCONTINUED (Pile ss Card 1 on Input Transformers) The manufacture of the following input tranformers has been discontinued and it is not considered necessary to maintain cmplete information in the catalogue. For information on codes not listed below, see other cards on input transformers.

Code Replaced by Code Replaced by Code Replaced by Code Replaced by

2OOA & B 215A 227C 243B 2olA to T 216A 2288 & B 244A 202A 218B 218G 229A 245A & B 203A to G 218C to F 230A & B 246A 205A to F 218R to N 231A 246C 207A 219A 2328 & B 247B 208A to L 220A 221D 233A & B 247D to H 208M 2408 220B 221D 233C 281A recom. 247K to N 208N to T 221B 224B 2333 & F 2488 208U 231B 221c 224C 233H 272C recm. 250A & B 208W & Y 221D 224A 2335 251A & D 208AA 223B 222A 233L 252B 208AB 223A to D 2348 to D 2538 208AD 224A 234A 2358 2548 208AF to AH 224B 234B 2368 255B to C 209A & B 224C 238A 2553 to H 210A to E 2258 & B 2398 2555 255K 211A to C 2268 240B to J 255K 212A & B 226B

(a) Replaced by a 634B together with one PlZA710 adapter, one P16A771 instruction sheet, form Pl11869 screws and four P242132 washers. INPUT TRANSFORMERS JAUUAK!l 1965 I (File as Card 2 on In1 put Transformers) I Coda Replaced by Code Replaced by Code Replaced by Code Replaced by

259A&B 274A 292D & E 633A 633G 26OAbrB 274C 298A 298B 633B 6331 261A 275A 299B 614A 633D 262A 2JJA to C 600B 638D 263A 279A 601A 6438 DlJ6227 264D 282C 603B 6448 265A to C 285A to D 611A 64JA 64JB 2668 61 B 285G to J 612A 64JC (a> 26JA 285N 613A 65JA 6 B 268A D93983 285B 614A 661B 2698 286A 615A 662A 2JOA to C 28811 2886 61JA 664A 663B 2JOE 288C 618D 669C 2JOF 2705 288D 618B raccm. 6228 672A 271A to K 2883 & F 629A 646B 6220A 272AErB 290A 630A (a) Replaced by 647D plus P13A263 instruction sheet. MARCH 1971 NE-213D INPUT STANDARD

Shell type coil enclosed in a metal case. Has an impedance ratio of 200 to 320,000 between windings (l-2) and (3-4).

Approximate dc resistance of windings (l-2) and (3-4) is 29.6 and 7826 ohms, respectively.

Arranged to mount on mounting plates. SEE RATINGS MAY 1972 NE-218 TYPE INPUT TRANSFORMERS BELOW

I I

Unpotted shell type transformers consisting of a coil wound on an insulated spool and assembled on a steel laminated core. Arranged to mount by two steel brackets which clamps to the core. Approximate overall dimensions are 3.188 inches high, by 2.0 inches long at the brackets, by 1.750 inches wide. For use in the 5A, 6A, and 7A amplifiers. NE-218A: Has four taps on the outer winding brought out to terminals. The ratio of transformation is variable from approximately 2 to 1, by means of taps, down to 0.35 to 1. NE-218G: The ratio of transformation between the inner windings and ttle two middle windings connected in series aiding is approximately 1 to 3.8.

Frequency Impedance (a)lnductance Code Winding Range (Hertz) Ratio (Ohms) (Henrys) Rating

[25 yin] NE-218A 20,000 to 80,000 Standard

(8 NE-218G 100 to 3000 20,000 to 290,000

(a) Tested at 900 hertz with a 3 volt drop across winding.

PROPERTIoFTHE Norrbern F/ethic MARCH 1971 NE-2318 INPUT TRANSFORMER STANDARD

3,;” Shell type transformer enclosed in a crosstalk-proof case arranged to mount on mounting plates.

Has three windings.

Resistance of inner windings (l-2) and (3-4) is approximately 33 ohms each, and of outer winding (5-6) is approximately 8,695 ohms.

Impedance ratio of windings (l-2.) (3-4) to (5-6) is 300 to 300,000. I STANDARD 233-D INP6T TFL'iNSFORKER I 1 ./I : ., Has a shell type permalloy core and is potted in a cast-iron c&se.,'-Has'an impedke ratio of 20,000 to 50;OO0 ohms between windings (l-2) (5-6) and (3-h) (7-8) and. oIj;e

Shell type transformers enclosed in metal cases arranged to mount on mounting plates.

No. of Approx. Resistance Code Fig. Wind---- of Each-.__- Winding~.~.__--.--. (Ohms) ~_ Impedance No. No. ings (1-2) (3-4) (5-6) (7-8) (5-12) Ratio Rating - ..~ (c)(d)240A 4 3 Cb)155 - -5420(a) 1 ~28. 5 i Standard FIG 2 24OC 1 4 G 400 G 400 -- (*) 620- 44800 NOT MANUF 24OD 1 4 6.5 3250 c.5 3250 - (‘:) 150-1,“oooo “ “ 240E 2 2 55 “70 - -- (.I) 4400-146000 “ “ 2408' 1 4 5s 1640 58 l640- (*) G40-240000 " (‘ 240G 1 4 40 1083 40 1083 - (*) G40-240000 “ 1‘ 240H 8 4 750 5000 750 5000- (*) 20000-500000 “ (‘ ( p ) Windings (l-2) (5-G) in series to (3-4) (‘7-8) in series. &-~z-xd_ -; _ f (-1-j Windin& (l-2‘) to (i-4). I~ NOS.240-C.D.F;G,ALSO (a) Windinrrs (l-2) (3-4) to (5-12). Taus cj.7.8.9.10,11,12 are 4.73 db each. GENERAL DESIGN AND ib) Windings il-2j (3-4j in series. ^ . DIMENSIONS OF NO. 240 (c) Provided with an extra terminal at “A.” (d) Replaces No. 208M. TYPE FIG 4 STANDARD JANUARY 1965 2f+'j'A INPUT TRANSFORMER

Designed to work from a 250 ohm resistance into a 23lD vacuum tube. Has an impedance ratio of 250 to 159,000 ohms between windings (l-2), (3-4) and (5-6) and operates over a frequency range from 35 to 10,000 cycles. Average DC resistance at 68O F. of windings (l-2) and (3-4) connected in series is approximately 75 ohms, of winding (5-6) is approately 5700 ohms. Over-all dimensions are approximately 2-7/8" x 2-7/8" x 4"* Originally intended for use in the 46~ amplifier. Also used in the 162Bl hit indi- cator circuit SD-70097-01. Has a small shell type core of per:nal..loy and is potted in a circular pressed steel can. Does not replace any apparatus. ,

8 PR o PE R T Y Norfbern Efectric Company L I MI T E D 249A INPUT TRANSFORMER STANDARD

.TANUARY 1965 i I Has an iqedance ratio of 20,000 to 50,000 ohms between the windings (l-2) (5-6) and (3-4) (7-81, and is designed to cover the frequent range of 60 to 5,000 cycles. The average DC resistance of windings (l-2) and (5-6 5 connected in series is 2830 ohms. Ttle average DC resistance of windings (3-4) and (7-8) connected in series is 4520 ohms. Has a shell type l+51i pemalloy core and is potted in a cast iron case, keasures overall approximately 2-5/8" x 3-3/16" x 3-15/l@. Intended for use as a low frequency oscillating coil in the 14-A and 15-A band fre- quency oscillators for cross-talk measurements. Does not replace any aprxwatus. SEE RATINGS JUNE 1972 NE-255 TYPE INPUT TRANSFORMERS BELOW

Each consists of windings on a permalloy core and enclosed in a metal case, Closest recommended mounting centres are 3.50 inches by 2.625 inches. NE-255L: Has a turns ratio of 22.4 to 1 between windings (3-5) and (l-2) and is intended to operate at 300 hertz. Intended for use in SD68190-01 test set in toll systems. NE-255M: -&i$ -z NE-255M Has an impedance ratio of 300 to 307,200 between windings - OTHERWISE SAME (2-l), (6-5), and (4-3), (8-7) and is intended to operate over AS NE-255L MAXT*-.$- c the frequency range of 1000 to 3000 hertz. t- Has an electrostatic shield between windings (2-l), (6-5), and (4-3), (8-7) connected to terminal S. Intended for use in SD95536-011 signalling receiving circuit in common systems. Approximate dc Resistance of Winding (Ohms) NE-255L Code (l-2) (3-4) (3-5) (5-6) (7-8) Rating NE-255L 130 4000 Standard II NE-255M (a) (3 - (a) (4 (a) Approximate dc resistance of windings (l-2) and (5-6) connected in series is 22 ohms and of windings (3-4) and (7-8) connected in series is 5800 ohms. STANDARD MARCH 1971 NE-266D INPUT TRANSFORMER

Shell type coil enclosed in a metal case. Approximate dc resistance of windings (l-2) (3-4) and (5-6) is 12.5, 12.5 and 7,000 ohms, respectively.

Has an impedance ratio of 200 to 100,000 between windings (l-2) (3-4) and (5-6).

Operates over the frequency range of 100 to 5,000 hertz.

Closest recommended mounting centres are 2.625 inches by 3.500 inches. STANDARD MARCH 1971 NE-270G INPUT TRANSFORMER I I

Shell type coil having a permalloy core enclosed in a metal case.

Approximate dc resistance of windings (1-Z) and (3-4) in series aiding is 67 ohms and of winding (5-6) is 1729 ohms. Has an impedance ratio of 300 to 3000 between windings (1-Z) (3-4) and winding (5-6) also 300 to 10.3 between windings (1-2) (3-4) and winding (6T-6) and 300 to 32 between windings (1-2) (3-4) and windings (5T-6).

Operates over the frequency range of 35 to 8000 hertz.

Provided with an electrostatic shield between windings.

Closest recommended mounting centres are 3.500 inches by 1.750 inches.

Intended for use in the J64OOlU amplifier rectifier panel for carrier systems. STANDARD MARCH 1971 NE-270H INPUT TRANSFORMER I

Shell type coil having a permalloy core enclosed in a metal case with a magnetic shield.

Approximate dc resistance of windings (1-Z) and (3-4) is 13.5 ohms each and of winding (5-7) is 1400 ohms.

Has an impedance ratio of 300 to 7,500 between windings (1-Z) (3-4) and (5-7).

Operates over the frequency range of 100 to 3,000 hertz.

Terminal 6 is a tap of winding (5-7) and is 15 dB below the full winding.

Provided with an electrostatic shield between windings (l-2) (3-4) and (5-7).

Closest recommended mounting centres are 1.750 inches by 3.500 inches.

Intended for use in the J64OOlW noise amplifier rectifier. MARCH 1971 NE-270 J INPUT TRANSFORMER (Card 1)

Consists of a shell type transformer having a permalloy core, a toroidal type coil and two resistors potted in a metal case. One resistor is connected between terminals 5 and R and the other is connected between the mid points of windings (l-2) and (3-4). STANDARD MARCH 1971 NE-270 J INPUT TRANSFORMER (Card 2) Has an impedance ratio of 600 to 405,600 ohms between windings (l-2) (j-4) and (5-6). Operates over the frequency range of 200 to 3200 hertz.

Approximate dc Resistance (Ohms) of Windinns (l-2) (3-4) (s-6) (l-4) (5-R) 9.5 9.5 5050 600 100,000 Closest recommended mounting centres are 1.750 inches by 3.500 inches. Each input transformer is stamped with a letter to indicate that the inductance is within the range shown in the following table.

Inductance (Henrys) of windings (l-2) and (3-4) in series aiding, (terminal 1 connected to 4 and terminal 3 grounded) and with 0.2 volt, 200 hertz ac, Class across the windings, falls within range of: A 3.00 to 3.667 B 3.668 to 4.333 C 4.334 to 5.00

In ordering input transformers for replacements in applications other than the A3 channel bank, no reference to class should be made. For replacements in the A3 channel bank, the class letter should be specified. Such orders will be filled, if possible, with the class ordered. However, if the class ordered is not available, an input transformer of a different class, as indicated below, may be substituted on the order. Orders for Class May be Filled with Class (a)A B or C B C C B (a) The circuit will have to be modified if a class B or C input transformer is substituted for a class A input transformer.

Q MAY 1972 NE-273A INPUT TRANSFORMER STANDARD

Has a shell type laminated core of silicon-steel and is potted in a cylindrical metal case having the terminal plate in the base.

Has an impedance ratio of 10,000 to 140,000 between windings (1-Z) and (3-4) (5-6) and oper,ltes over the frequency range of 100 to 5,000 hertz.

Approximate overall dimensions are ‘2.675 inches by 2.875 inches by 3.562 inches high, exclusive of the terminals.

Intended for use in the 85A amplifier where it works out of a 244A vacuum tube into two NE-275A vacuum tubes connected in push-pull.

Approximate Winding dc Resistance (Ohms)

(l-2) 2200 (3-4) 4200 (5-h) 4200 MAY 1972 NE-276A INPUT TRANSFORMER STANDARD

Has a shell type butt joint core of chromium-permalloy and is potted in a metal case arranged for single side mounting.

Has an impedance ratio of 20,000 ohms to 605,000 ohms between windings (Z-l) (6-5) and (4-3) (8-7) and operates over .the frequency range of 100 to 5,000 hertz.

The dc resistance of windings (2-l) and (6-5) connected in series is approximately 1,000 ohms.

The dc resistance of windings (4-3) and (8-7) connected in series is approximately 7,300 ohms.

Approximate overall dimensions are 1.688 inches by 3.281 inches by 3.438 inches high, not including the terminals.

Closest recommended mounting centres are 1.750 inches by 3.50 inches.

Used in the carrier and motor control oscillator, which is part of the 568730 telephotograph system, where it operates between two 102D vacuum tubes. MARCH 1971 NE-277D INPUT TRANSFORMER STANDARD

Consists of windings on a permalloy core potted in a metal case.

Has an impedance ratio of 600 + 600 to 135,000 ohms between windings (3-4) + (7-8) to (l-2) (5-6).

Terminals 3T and 8T are centze taps of windings (3-4) and (7-8), respectively.

Intended to operate over the frequency range of 300 to 2700 hertz.

An electrostatic shield between windings (3-4) (7-8) and (l-2) (5-6) is connected to the case. Closest recommended mounting centres are 2.625 inches by 3.500 inches.

Approximate dc Resistance Winding (Ohms)

(l-2) 1800 (3-4) 75 (s-6) 1800 (7-g) 75 MARCH 1971 NE-280A INPUT TRANSFORMER STANDARD

Shell type coil enclosed in a sheet metal case. ---T 7 I Closest recommended mounting centres are 2.625 inches by 3.500 inches. I I' .. I"35 Has an impedance ratio of 300 to 30,000 between windings (Z-l) (6-5) and 2; 1 I (4-3) (8-7). i I 4 ,"I Operates over a frequency range of 60 to 5000 hertz. $22 I r-It-1 Provided with an electrostatic shield between windings (2-l) (6-5) and (4-3) (8-7).

Approximate dc resistance of windings (2-l) and (6-5) is 47.5 ohms each and of windings (4-3) and (8-7) is 1950 ohms each.

Intended for use in 5687368 volume limiter. JANUARY 1965 Nos. 281~4 & B INPUT TRANSFORMERS SEE RATINGS BELOW

Each consists of windings on a permalloy core potted in a metal can. Closest recommended mounting centers are 2-5/8 inches by 3-l/2 inches. No. 281A: Has an impedance ratio of 500 to 100,000 ohms between windings (l-2) (3-4) and (5-6). Intended to operate over the frequency range of 30 to 7000 c.p.s. Intended for use in the J68’736A volume limiter.

NO. 281B: Has an impedance ratio of 16,660 to 64,000 ohms between windings (l-2) (5-6) and (3-4) (7-8). Intended to operate over the frequency range of 40 to 6000 c.p.s. Intended for use in the J68326B B2 voice operated gain adjusting device in radio telephone systems.

Approx. D.C. Resistance Code (Ohms) of Winding No. (l-2) (3-4) (5-6) (7-8) Replaces Rating 281k ‘76 76 6700 StOndCUd 281,B 1300 2600 1300 2600 D-157347 “

N0.2SiA. ALSO GENERAL DESIGN AND DIMENSIONSOF NO. 281 TYPE DECEMBER 1972 NE-2828 INPUT TRANSFORMER STANDARD

Shell type transformer with a silicon steel core potted in a metal case arranged for single side mounting. Has five flexible leads which are connected to terminals inside the case, and extend approximately 14.00 inches outside the case.

Has an impedance ratio of 600 to 120,000 between windings (l-2) and (3-5) and operates over the frequency range of 100 to 5,000 hertz.

Approximate dc resistance of the windings are as follows:

Approximate Winding dc Resistance

(l-2) 78 ohms (3-4) 2,208 ohms (3-5) 4.940 ohms

Approximate overall dimensions are 1.750 inches by 1.750 inches by 3.250 inches.

Closest recommended mounting centres are 1.812 inches by 1.812 inches. MARCH 1971 NE-283A INPUT TRANSFORMER STANDARD

Toroidal type coil with permalloy core enclosed in a sheet metal case.

Closest recommended mounting centres are 1.750 inches by 3.500 inches.

Has an impedance ratio of 1 to 92 between windings (l-2) and (3-4).

Operates over the frequency range of 10200 to 10400 hertz.

Approximate dc resistance of winding (l-2) is 0.22 ohm and of (3-4) is 11.5 ohms. I JANUARY 1965 284A ll@UT~?SFORI~:II STANDARD I It is expected that this transformer !:Gll be furnished to customers only as a part of coded assemblies. Shell type transformer having a chromium-permalloy core potted in a sheet metal case provided llith lugs for mounting. Provided with an electromagnetic shield, Has an impedance ratio of 400:116,000 between windings (l-2) and (3-4) and operates over the frequency range of 60 to 10,000 cycles per second. The DC resistance of winding (l-2) is approximately 110 ohms and the K resistance of winding (34) is approximately 4400 ohms, Overall dimensions are approximately l-1/4" x 2-19/32" x 2-19/32". Closest recommended mounting centers are l-11/32" x 2-21/32". Intended for use in the 2A ISoise Ileasuring Set in telephone circuits where it operates out of a variable impedance of 70 to 200 ohms into a 2d4A vacuum tube. MARCH 1971 NE-285E & F INPUT TRANSFORMERS SEE RATINGS BELOW

Each consists of windings on a permalloy core and potted in a metal case which contains a magnetic shield. Closest recommended mounting centres are 1.812 inches by 1.812 inches. NE-285E: Has an impedance ratio of 600 to 25,000 ohms between windings (Red Red-White) (Blue Blue-White) and (Green Green-White). Intended to operate over the frequency range of 35 to 10,000 hertz. Provided with electrostatic shields between the windings, connected to Black lead. Intended for use in the NE-13A transmission measuring set. NE-285F: Has an impedance ratio of 30 to 165,000 ohms between windings (Red Red-White) and (Green Green-White) and 250 to 165,000 ohms between windings (Red Blue) and (Green Green- White). The Red-White lead is a tap on winding (Red Blue). Intended to operate over the frequency range of 30 to 10,000 hertz. Provided with an electrostatic shield between the connected to Black lead. NE-285E NE-285F windings, Approximate dc Resistance (Ohms) of Winding Code (Red Blue) (Green Green-White) Rating NE-285E (a) 27 1170 Standard NE-285F 18.7 3570 II (a) With Red-White lead connected to Blue-White lead. MARCH 1971 NE-285 K INPUT TRANSFORMER STANDARD

Consists of windings on a permalloy core and potted in a metal case which contains a magnetic shield. Has an impedance ratio of 15,000 to 80,000 ohms between windings (Red Red-White) and (Blue-Green). Intended to operate over the frequency range of 50 to 10,000 hertz. Provided with electrostatic shields between the windings. These shields are connected to the shielding around the Red and Red-White leads.

Approximate dc Resistance Winding (Ohms) (Red Red-White) 860 (Blue Blue-White) 1350 (Blue-White Green) 1350 Lead (Blue-White) is a mid-tap on winding (Blue Green). Closest recommended mounting centres are 1.812 inches by 1.812 inches. Intended for use in NE-14 local test desk. MARCH 1971 NE-285 L INPUT TRANSFORMER STANDARD

. . . ‘; - Consists of windings on a permalloy core and potted in a metal case which ,,.. ,.. 164”.32 THREAD - <-y- ( 2 HOLES contains a magnetic shield. Has an impedance ratio of 600 to 75,000 ohms between windings (Red Blue-White) and (Green Green-White) and 30 to 75,000 ohms between windings (Red-White Blue) and (Green Green-White).

Intended to operate over the frequency range of 30 to 10,000 hertz.

Closest recommended mounting centres are 1.812 inches by 1.812 inches. Provided with electrostatic shields between the windings, connected to Black lead.

Winding Approximate dc Resistance (Ohms) (Red Blue-White) 63 (Red-White Blue) 3.1 (Green Green-White) 2275 MARCH 1971 NE-285P INPUT TRANSFORMER STANDARD

Consists of windings on a pennalloy core and potted in a metal case which contains a magnetic shield.

/.164”-32 THREAD Has an impedance ratio of 500 to 200,000 ohms between 2 HOLES windings (Red Red-White) and (Blue Green), (Green-White Brown- White). Intended to operate over the frequency range of 40 to 10,000 hertz. Provided with electrostatic shields between the windings, connected to Black lead. .I4”LONC r’ Winding Approximate dc Resistance (Ohms) -f (Red Red-White) 36 (Blue Green) 1580 (Green-White Brown-White) 1580

Leads Blue-White and Brown are taps on windings (Blue Green) and (Green-White Brown-White), respectively. Connection to these taps provides an output voltage 10 dB below that of the full winding. Closest recommended mounting centres are 1.812 inches by 1.812 inches. Intended for use in SD-59373-01 NE-72A frequency meter transmission measuring circuit. MAY 1972 NE-287C INPUT TRANSFORMER STANDARD

Consists of a coil potted in a metal case.

Closest recommended mounting centres are 1.750 inches by 3.50 inches.

Has an impedance ratio of 150 to 300,OOC ohms between windings (l-Z), (3-4), and (5-6). Series aiding connection can be obtained by strapping terminal 2 to 3.

Approximate dc resistance of windings (l-Z), (3-4) and (5-6), are 3.05, 3.05 and 3480 ohms, respectively.

r Operating frequency of 100 to 3,000 hertz.

Intended for use in the J68323F radio telephone C4 control terminal receiving amplifier detector in toll systems.

PROPERTYOFTHE Northern E/ectric COMP4NYilMl~~~ MARCH 1971 NE-288 B INPUT TRANSFORMER I STANDARD

shell type coil with permalloy core enclosed in a sheet metal case.

Closest recommended mounting centres are 1.812 inches by 1.812 inches.

Has an impedance ratio of 600 to 300,000 between windings (Red Red-White) and (Blue Blue-White).

Average dc resistance of windings (Red Red-White) is 48 ohms and of winding (Blue Blue-White) is 4,510 ohms.

Intended to operate over the frequency range of 400 to 3,000 hertz.

Intended for use in a portable test set in carrier telegraph systems. MARCH 1971 NE-289A INPUT TRANSFORMER STANDARD

Consists of windings on an air core, potted in a metal case.

Approximate dc resistances of windings (l-2). (3-4) and (5-6) are 11.3 ohms, 23.0 ohms and 9.0 ohms, respectively.'.

I--IA Closest recommended mounting centres are 1.594 inches by 1.906 inches. Forms a part of the NE-19C oscillator. MARCH 1971 NE-292A INPUT TRANSFORMER STANDARD

Consists of a spool type coil with ring type permalloy powder core, a capacitor and a resistor potted in a sheet metal case.

Has an impedance ratio of 600 to 30,000 between terminals (l-2) and (3-4).

Average dc resistance between terminals (3-4) is 200 ohms.

Operates over the frequency range of 60 kHz to 108 kHz.

Closest recommended mounting centres are 3.500 inches by 1.750 inches.

Provided with an electrostatic shield between windings.

Intended for use in the auxiliary amplifier in the K type carrier terminal equipment. MARCH 3.971 NE-292 C INPUT TRANSFORMER STANDARD

Consists of a spool type coil with ring type permalloy powder core, and a resistor potted in a sheet metal case.

Has an impedance ratio of 125 to 15,000 between windings (l-2) and (3-4).

Approximate dc resistance of windings (l-2) and (3-4) is 0.8 ohm and 36.5 ohms, respectively.

Operates over the frequency range of 400 kHz to 448 kHz.

Provided with an electrostatic shield between windings.

Closest recommended mounting centres are 3.500 inches by 1.750 inches.

Intended for use in the 5687498 modulator and intermediate amplifier panel of the J type carrier telephone system. No. 292F INPUT TRANSFORMER STANDARD .~muiiRY 1965 I Consists of a spool type coil with a ring type permalloy powder core and a resistance enclosed in a metal case. Has an impedance ratio of 600 to 40,000 between windings (1-Z) and (3-4). Operates at a frequency of 120,000 cycles per second. Terminal T is a in winding (l-2). Has an electrostatic shield between windings (l-2) and (3-4). The resistance is connected between terminal 4 and terminal 8, with taps connected to terminals 5, 6 and 7. Approximate D. C. resistance between terminals is as follows: Resistance 0.8 (3-4) 42 (4-5) 8,000 (4-6) 14,800 (4-7) 20,000 (4-8) 40,000 (‘lose& recommended mounting centers are 3-l/2 inches by l-3/4 inches. Intended for use in the J68735C amplifier and filter unit in the carrier supply equipment for type “K” carrier telephone systems. MARCH 1971 NE-292G INPUT TRANSFORMER STANDARD

spool type coil having a toroidal type permalloy powder type coil, a resistor and capacitors enclosed in a metal

125 to 20,000 between windings (l-2) and (3-4).

Operates over a frequency range of 92,000 to 143,000 hertz.

Provided with an electrostatic shield between windings (l-2) and (3-4).

Approximate dc resistance of winding (3-4) is 120 ohms.

Closest recommended mounting centres are 3.500 inches by 1.750 inches.

Intended for use in the 568762G supplementary amplifier for 52 carrier terminal equipment. NE-292H INPUT TRANSFORMER STANDARD

Consists of a spool type coil, having a toroidal type permalloy powder core, enclosed in a metal case.

Has an impedance ratio of 135 ohms to 40,000 ohms between winding (1-Z) and windings (3-4), (5-6) and is designed to operate at 64,000 hertz.

Approximate dc resistance of winding (1-2) is 1 ohm and of windings (3-4), (5-6) connected in series is 103 ohms.

Has an electrostatic shield between winding (l-2) and windings (3-4), (5-6). Closest recommended mounting centres are 1.750 inches by 3.50 inches.

Intended for use in the 368775s frequency comparison circuit for the L type carrier telephone system. Intended to operate from a 135 ohm circuit into a resistance-capacity bridge which is in the grid circuit of a NE-311B electron tube. MARCH 1971 SEE RATINGS NE-294 TYPE INPUT TRANSFORMERS BELOW

Non-magnetic core coil enclosed in a metal case.

Have an impedance ratio of 1 to 1 between windings (l-2) and (3-4).

Closest recommended mounting centres are 1.344 inches by 1.562 inches.

Approximate dc Resistance Frequency of Windings (Ohms) Range Code (l-2) (3-4) (kH;) Rating NE-294A 900 5000 60 to 108 Standard NE-294B 1100 1100 35 to 150 II NE-294C 125 125 300 to 550 II NE-294D 30 30 300 to 550 0, ~Ata..rArtY 1965 STANDARD 296A It??W TRANSFOmm

It is expected that this input transformer will be furnished to customers only as a part of coded assemblies. An air core type transformer with a sheet copper case which is equipped with mount- ing lugs. Has a voltage stepdown of 4 to 1 between windings (3-4) and (l-2) and is designed to be tuned to any desired frequency in the range of 500 to 650 KC. The average DC resistance of the windine is as follows. Winding Resistance .12 ohm ;;z; .35 ohm Overall dimensions are approximately 2-9/16* x 4-l/8" x 3-13/16" high. Closest recommended mounting centers are 2-5/S" x 4-3/16". Intended for use as an oscillating coil in the 17A oscillator for testing and maintenance of types J and K carrier systems. Does not replace any existing apparatus, STANDARD JANUARY 1965 297A INPUI TR$WSZ!ORi@B

It is expected that this input transformer will be furnished to customers only as a part of wded assemblies. A core type transformer with a toroidal permalloy core , potted in a rectangular metal case which is equipped with mounting lugs. Has an impedance ratio of 250 to 25,000 between windings (l-2) and (3-4) (5-6) and is designed to transmit a single frequency of 650 KC. The average DC resistance of the windings is as follows: Winding Resistance (l-2) .5 ohm (3-4) 10. OhIIlS (5-6) 10. ohms Overall dimensions are approximately l-7/16" x 3" x 3-3/8" high. Closest recommended mounting centers are l-1/2" x 3-l/16*. Intended for use in the 17A oscillator for testing and maintenance of type "J" and "K" carrier systems. Does not replace any existing apparatus. SEE RATINGS JANUARY 1965 Nos. 298A & B INPUT TRANSFORMERS BELOW

Shell type coil having a permalloy core enclosed in a metal case. Have an impedance ratio of 135 + 67.5 to 7500 between windings (l-2) (3-4) and (5-6). Operates over the frequency range of 35 to 150 kilocycles. Approximate D.C. resistance of windings (l-2) and (3-4) is .15 ohm each and of winding (5-6) is 25 ohms. Provided with an electrostatic shield between windings (l-2) (3-4) and (5-6). Closest recommended mounting centers are 2-5/X inches by NO5 298A 6 8 O-l/Z inches. Intended for use in the J68748A and J68748B amplifiers in the type “J” carrier system.

Code No. Rating -7 i I 1

I III m8A NOT MANUFACTURED

1 4; 298B Standard d ,.a

3- I ‘6 I I

I 1

J-L MARCH 1971 NE-299A INPUT TRANSFORMER STANDARD

Air core coil enclosed in a sheet metal case.

Approximate dc resistance of windings (l-4) and (5-6) are 1.25 and 25 ohms, respectively.

Operates primarily at a frequency of 7150 hertz.

Closest recommended mounting centres are 2.625 inches by 3.500 inches.

Intended for use in the oscillator of type "Hl" carrier telephone system. MARCH 1971 NE-6OOA INPUT TRANSFORMER STANDARD

Shell type coil having a silicon steel core and enclosed in a metal case.

Average dc resistance of winding (l-2) is 12.5 ohms and of (3-4) is 3140 ohms.

Has an impedance ratio of 600 to 450,000 between windings (l-2) and (3-4).

Operates over the frequency range of 4000 to 10,000 hertz.

Has an electrostatic shield between windings.

Closest recommended mounting centres are 1.750 inches by 3.500 inches.

Intended for use in type "Hl" carrier telephone terminal and repeater equipment. MARCH 1971 NE-6OOC INPUT TRANSFORMER STANDARD

Shell type coil having a silicon steel core enclosed in a metal case.

Has a turns ratio of 1 to 3.16 between windings (l-2) and (3-4).

Operates over the frequency range of 200 to 3000 hertz.

Approximate dc resistance of winding (1-Z) is 210 ohms and of winding (3-4) is 128 ohms.

Closest recommended mounting centres are 1.750 inches by 3.500 inches. NE-602A INPUT TRANSFORMER

Shell type coil having a permalloy core and enclosed in a metal case.

Average dc resistance of winding (l-2) is 1200 ohms and of (3-6) is 1550 ohms.

Operates between two 310A electron tubes.

Has a turns ratio of 1:l between winding (l-2) and (3-6), with taps 4 and 5 in the high winding to give voltage ratios of 12 dB and 6 dB, respectively below maximum.

Operates at a frequency of 1300 hertz.

Closest recommended mounting centres are 1.750 inches by 3.50 inches.

Intended for use in the 368605K voice operated loss control and suppressor panel. MARCH 1971 NE-602B INPUT TRANSFORMER STANDARD

Shell type coil having a permalloy core and a capacitor enclosed in a metal case.

Has an impedance ratio of 30,000 to 100,000 between windings (l-2) and (3-5).

Approximate dc resistance of winding (l-2) is 10.8 ohms and of winding (3-5) is 45.8 ohms.

A capacitor of approximately 0.003 PF is connected between terminals 3 and 5.

Terminal 4 is a centre tap of winding (3-S).

Operates at a single frequency of 4,000 hertz and discriminates against 8,000 hertz.

Has an electrostatic shield between windings.

Closest recommended mounting centres are 1.750 inches by 3.500 inches. MARCH 1971 NE-602 C INPUT TRANSFORMER STANDARD

Shell type coil having a permalloy core and enclosed in a metal case.

Has an impedance ratio of 600 to 190,000 between windings (Z-l) (6-5) and (4-3) (8-7).

Operates at a frequency of 1,000 hertz.

Approximate dc resistance of windings (2-l) (6-5) is 2.6 ohms and of windings (4-3) (8-7) is 4,000 ohms.

Closest recommended mounting centres are 1.750 inches by 3.500 inches.

Intended for use in the J68602AW ringer oscillator.

L SEE RATINGS JANUARY 1965 Nos. 603A, B & C INPUT TRANSFORMERS BELOW

Each consists essentially of windings on a silicon steel core potted in a metal can. Closest recommended mounting ccnte1.s are 3-3/16 inches by l-3/4 inches. No. 603A: Has an impedance ratio of 600 to 150,600 ohms between windings (l-2) (3-4) and (5-6). A 600 ohm resistance is connected between terminals 1 and 4. Intended for use in the J68’757B modulator-demodulator panel in connection with the C5 carrier telephone terminal. No. 603B: Has an impedance ratio of 1,200 to 4,800 ohms between windings (1-2) and (3-4). NO. 6038. Provided with an electrostatic shield between windings. The shield is connected to terminal “S” A 36 000 ohm resistance is connected between terminals 1 and R. Intended for use in the J68735A carrier generator in the type “K” cable carrier system. No. 603C : Has an impedance ratio of 1 to 3,000 ohms between windings (l-2) and (3-4) (5-6). Series aiding connection can be obtained by strapping terminal 4 to 5. Provided with an electrostatic shield between windings (1-2) and (3-4) (5-6). The shield is connected to terminal “S”. Intended for use in the J67424 frame identification frequency supply frame for the Nos. 4 or 4A toll switching’system. NO. 603C. Resistance of Windings _.__~--~ (Ohms) -~- - Frequency Range (5-6) (Cycles per Sec.) Rating __..-22: ___(l-2) (3-4)

NO. 603A. ALSO GENERAL DESIGN :% 2611.5 11.5 7430 250 4,000to 2,800 NOTStandard MANUF AND DIMENSIONS OF NO. 603 TYPE (*)603c .25 3: 360 426 to 1,615 Standard (*) Replaces D-157128.

8 PR o P ER T Y Nortbern E/ectric Company L I M I T E D MARCH 1971 NE-604A INPUT TRANSFORMER STANDARD

1 Spool type coil with permalloy ring core potted with 2 capacitors and 3 resistors enclosed in a metal case.

Has an impedance ratio of 1:l between terminals (l-2) and (3-4).

Average dc resistance between terminals 1 and 2 is 10,800 ohms and between terminals 3 and 4 is 100,000 ohms.

Operates over the frequency range of 5,000 to 30,000 hertz.

Closest recommended mounting centres are 1.750 inches by 2.250 inches.

Intended for use in the 568756B carrier telephone amplifier. , MARCH 1971 NE-605A INPUT TRANSFORMER STANDARD

Spool type coil having a permalloy core enclosed in a metal case.

Has an impedance ratio of 400 + 600: 450,000 between (l-2) (3-4) and (5-6).

Average dc resistance of winding (l-lT-2) and (3-3T-4) is 1.8 ohms each and of winding (S-6) is 21,800 ohms.

Operates over the frequency range of 5,000 to 30,000 hertz.

Has an electrostatic shield between winding (5-6) and other windings.

Closest recommended mounting centres are 2.125 inches by 3.500 inches.

Intended for use in the J68756B amplifier in the C5 carrier terminal and the Cl carrier repeater. NE-605B INPUT TRANSFORMER STANDARD

Consists of windings on a permalloy core and potted in a metal case.

Has an impedance ratio of 8000 to 8000 between windings (l-2) (3-4) and (5-6).

Operates over the frequency range of 1000 to 150,000 hertz.

An electrostatic shield between winding (5-6) and the other windings is JC4 3 connected to terminal S. THWA,, Closest recommended mounting centres are 1.750 inches by 3.500 inches.

Intended for use in the J64031A transmission measuring set for K2 carrier telephone systems.

Approximate dc Resistance Winding (Ohms)

(l-2) 39 (3-4) 39 (5-h) 78 SEE RATINGS MARCH 1971 NE-606A & NE-607A INPUT TRANSFORMERS BELOW

Toroidal type coils each having a permailoy ring core and an inductor enclosed in a metal case. Winding (1-Z) is the plate winding, (3-8) is the oscillating winding, (9-14) is the output winding. An inductor is connected to terminals 9 and 15. Terminals 4, 5, 6 and 7 are taps in winding (3-8) and terminals 10, 11 12 and 13 are taps in windings (9-14). Operates at single frequencies in the range specified below. Closest recommended mounting centres are 2.688 inches by 3.562 inches. Intended for use in the C5 carrier system terminals.

1 i Approximate dc Resistance Frequency I j (Ohms) of Windings 1 I Range Code (l-2) (3-81 (9-14) (9-15) (Hertz) Rating NE-606A 0.35 1.00 0.35 8.8 6,000 to 13,000 Standard NE-607A 0.5 1.9 0.4 2.4 17,500 to 30,000 II NE-608A INPUT TRANSFORMER STANDARD

Shell type coil with permalloy core and two NE-12OH resistors enclosed in a metal case.

Has an impednace ratio of 300 to 30,000 between windings (l-2) and (5-13).

Operates over a frequency range of 30 to 8,000 hertz.

Approximate dc resistance of winding (l-2) is 34 ohms and of winding (5-13) is 2330 ohms.

Approximate dc resistance between terminal (l-3) and (2-4) is 300 ohms each.

Terminals 6, 7, 8, 9, 10, 11, and 12 are taps of winding (5-13), which provide a gain control in four steps of 10 dB each.

Closest recommended mounting centres are 3.50 inches by 4.938 inches.

Intended for use in the 568617W amplifier. MARCH 1971 NE-609A INPUT TRANSFORMER STANDAFXI

Shell type coil having a permalloy core and enclosed in a metal case.

Approximate dc resistance of windings (l-2) (5-6) is 7840 ohms and of windings (3-4) (7-8) is 7840 ohms.

Has an impedance ratio of 2,000,OOO to Z,OOO,OOO between windings (1-Z) (5-6) and (3-4) (7-8).

Operates over the frequency range of 30 to 8,000 hertz.

Closest recommended mounting centres are 3.500 inches by 4.938 inches.

Intended for use in the J68617W amplifier. SEE RATINGS MARCH 1971 NE-619 A&B INPUT TRANSFORMERS BELOW

Duolateral wound coils each having a permalloy powder core and enclosed in a metal case. Have impedance ratios of 25,000 to 175,000 between windings (l-2) and (3-4). Have electrostatic shields between windings. Closest recommended mounting centres are 1.750 inches by 2.625 inches. Intended for use in the 568762 pilot channel amplifier in the 52 type 1’9 . carrier telephone systems. NE-619A: Operates on single frequencies in the range from 58,000 to 80,000 hertz. NE-619B: Operates on single frequencies in the range from 92,000 to 143,000 hertz.

Approximate dc Resistance of Windings (Ohms) Code (l-T-2) (3-4) Rating NE-619A 13 113 Standard NE-619B 7.5 75 II MARCH 1971 NE-619C INPUT TRANSFORMER STANDARD

7- I Core type coil, having a permalloy powder core ring, potted in a metal I,.. case. -T ‘76 g’ Has an impedance ratio of 100 to 300,000 ohms between windings (l-2) --‘i. and (5-6) or 150 to 300,000 ohms between windings (3-4) and (5-6) and operates at 128 kHz when tuned with a variable capacitor across winding (5-6). The capacitor is part of the circuit in which this input transformer is used. Has an electrostatic shield between windings (5-6) and (l-2) (3-4).

Closest recommended mounting centres are 1.750 inches by 2.625 inches.

Intended for use in the J68775U 4 kHz frequency supply circuit for the L type carrier telephone system.

Approximate dc Resistance Winding (Ohms)

(l-2) 0.15 (3-4) 0.175 (5-b) 37.0 MARCH 1971 NE-6206 INPUT TRANSFORMER STANDARD

Consists of duolateral windings on a toroidal type permalloy powder core and is potted in a metal case.

Intended to operate at a single frequency of 20 kHz out of an NE-396A electron tube, connected in push-pull as an oscillator, into an NE-412A

Has a turns ratio of 1 to 1.8 between windings (l-3) and (4-6).

Approximate dc resistances of windings (l-3) and (4-6) are 160 ohms and 800 ohms, respectively. Terminals 2 and 5 are centre taps of windings (l-3) and (4-6), respectively.

Closest recommended mounting centres are 1.750 inches by 2.625 inches.

Intended for use in the J68336D FM terminal transmitter control panel of the NTD-2 radio system. No. 624A INPUT TRANSFORMER STANDARD JANUARY 1965

Toroidal type coil having a permalloy powder rore ant1 potted in a metal case. Operates at a frequency of 85 cycles per second. Approximate D.C. resistance of winding (l-2) is 45 ohms and of winding (3-4) is 300 ohms. Closest recommended mounting centers are 7 inches by 7 inches. Intended for use in the base frequency oscillator panel of the 140A-1 carrier supply common frequency control circuit. JUNE 1972 SEE RATINGS NE-626A BI B INPUT TRANSFORMERS BELOW

Each transformer consists of a shell type coil with a permalloy core enclosed in a metal case. Closest recommended mounting centres are 1.750 inches by 1.750 inches. NE-626A: Impedance ratio of windings (8-9) to (l-7) is 300 to 357,000. Operates over the frequency range of 250 to 3000 hertz. Approximate dc resistance of winding (8-9) is 7.8 ohms, and of winding (l-7) is 3,650 ohms. Has five taps (2, 3, 4, 5, and 6) on the high side spaced at 4 dB intervals from terminal 1 with terminal 7 the common terminal. Intended for use in the Vl telephone repeater and associated equipment (J68635A). NE-626B: Impedance ratio of windings (l-2) to (7-8) is 300 to 30,000. Operates over the frequency range of 8000 to 64,000 hertz. Approximate dc resistance of winding (1-2) is 2.9 ohms, and of winding (7-8) is 205 ohms. Has an electrostatic shield between windings. The shield is connected to terminal 3. Intended for use in the J68775U 4 kHz frequency supply circuit for the L type carrier telephone system.

Code Rating

NE-626A Standard NE-626B ,, SEE RATINGS MARCH 1971 NE-626 E&F INPUT TRANSFORMERS BELOW I I Each consists of windings on a permalloy core potted in a metal case. The

FOR NUMBER OF mounting screws are electrically connected to the core and case. TERMINALS SEE TEXT; Closest recommended mounting centres are 1.750 inches by 1.750 inches. NE-626E: Has impedance ratios of 300 to 300 ohms between windings (l-2) and (3-4), 300 to 4250 ohms between windings (l-2) and (7-8), 300 to 8500 ohms between windings (l-2) and (7-g), 300 to 70,000 ohms between windings (1-2) and (7-10) and 300 to 140,000 ohms between windings (l-2) and (7-11). Terminals 8, 9 and 10 are taps on winding (7-11). Operates over the frequency range of 200 to 3500 hertz. Intended for use in the 1600 or 2000 hertz single frequency signalling circuit for toll systems. NE-626F: Has an impedance ratio of 600 to 3000 ohms between windings (l-2) and (3-4). Operates over the frequency range of 50 to 5000 hertz. Intended for use in the J98703W schedule A & B program channel unit of the NE-N1 carrier telephone system.

Approximate dc Resistance of Winding (Ohms) Code Terminals (l-2) (3-4) (7-B) (7-9) (7-10) (7-11) Rating

NE-626E 1 to 4 incl & 41 160 665 950 2865 4230 Standard 7 to 11 incl NE-626F 1 to 4 incl 28 130 - II SEE RATINGS JUNE 1972 NE-627 TYPE INPUT TRANSFORMERS BELOW

Toroidal type coils, each having a permalloy powder core and enclosed in a metal case. Have turns ratio of 1:l between windings (l-2) and (3-4). Operate at fixed frequencies in the voice frequency range when tuned with external capacitances. Closest recommended mounting centres are 5.250 inches by 5.250 inches. Intended for use in the channel frequency oscillators in the 140Al carrier supply in telegraph systems.

Resistance Code Windings (Ohms) Rating

(l-2) 55 NE-627A c (3-4) 140 Standard 2 NE-627B (l-2) II I (3-4) 9 3 NE627C I :z; 13.5 1 II 70 NE-627D (l-2) 3.5 3 11 (3-4) 15

NE- 627A ALSO GENERAL DESIGN AND DIMENSIONS OF NE-627 TYPE MARCH 1971 NE -628A INPUT TRANSFORMER STANDARD

Shell type coil having a silicon steel core and enclosed in a metal case.

Has an impedance ratio of 600 to 25,000 between windings (l-2) and (3-4).

Operates over the frequency range of 255 to 3145 hertz. b-d--A. Provided with an electrostatic shield between windings.

Approximate dc resistance of winding (l-2) is 50 ohms and of winding (3-4) is 2700 ohms.

Closest recommended mounting centres are 1.750 inches by 2.625 inches.

Intended for use in connection with type 4OC-1 carrier telegraph equipment. MARCH 1971 NE-632A INPUT TRANSFORMER STANDARD

Toroidal type coil, having a permalloy powder core and enclosed in a metal case.

Has a turns ratio of 1:l between windings (l-2) and (3-4).

Operates as an oscillator coil at a frequency of 255 hertz.

Approximate dc resistance of winding (l-2) is 55 ohms, and of winding (3-4) is 140 ohms.

Closest recommended mounting centres are 5.250 inches by 5.250 inches. MARCH 1971 NE-633 TYPE INPUT TRANSFORMERS SEE RATINGS BELOW (Card 1)

\FOR NUMBER OF TERMINALS Shell type transformers each having a permalloy core and potted in a metal case. , SEE TEXT The mounting screws are electrically connected to the case and core. Closest recommended mounting centres are 1.750 inches by 1.750 inches. NE-633C: Has an impedance ratio of 600 to 75,000 ohms between windings (l-2) to (7-8). Intended to operate over the frequency range of 40 to 8,500 hertz. Intended for use in the Kl carrier telephone system. NE-633G 6 H: Intended for use in the 568777 compandor. Intended to operate over the frequency range of 50 to 8000 hertz. NE-633G: Has an impedance ratio of 40,000 to 80,000 ohms between windings (l-2) (3-4) to (7-8). NE-633H: Has an impedance ratio of 100 to 200,000 ohms between windings (l-2) (3-4) to (7-8).

Approximate dc Resistances Terminals (Ohms) of Windings in Code Positions (l-2) (3-4) (5-6) (7-8) (7-9) Rating (b)(c)NE-633C 1,2,7,8&g 63 2275 - Standard (a)(b)(d)NE-633G 785 785 - 4935 - II (a)(b)(d)NE-633H I:; 1.26 1.26 - 9200 - II (a) Has an electrostatic shield between windings (l-2) (3-4) and (7-8) which is connected to terminal 9. Terminal 10 is connected to the core and case. (b) Case provides magnetic shielding. (c) Has an electrostatic shield between windings which is connected to terminal 9. (d) Series aiding connections can be obtained by strapping terminal 2 to 3. (e) Has terminals in positions 1 to 4, inclusive, and 7 to 10, inclusive. MARCH 1971 NE-633 TYPE INPUT TRANSFORMERS SEE RATINGS (Card 2) BELOW

NE-633K: Has an impedance ratio of 600 to 600 ohms between windings (l-2) to (7-8), and 600 to 900 ohms between windings (1-Z) to (7-9). Intended to operate over a frequency range of 100 to 5000 hertz. Intended for use in the J94022A power reference meter. NE-633L: Has an impedance ratio of 600 to 600 ohms between windings (l-2) (5-6) to (3-4) (7-8). Intended to operate over the voice frequency range. Initial use: SD-26153-01 operator junctor circuit.

Terminals Approximate dc Resistances in (Ohms) of Windings Code Positions (l-2) (3-4) (5-b) (7-8) (7-9) Rating NE-633K 1,2,7,8 & 9 9 13.5 Standard NE-633L (a) 4.3 4.6 4.3 4.6 0

(a) Has terminals in positions 1 to 4, inclusive, and 7 to 10, inclusive, numbered 1, 2, 5, 6, 3, 4 7 & 8, respectively. Terminals are arranged for mechanically wrapped connections. MARCH 1971 NE-634A INPUT TRANSFORMER STANDARD

FOR NUMBER OF TERMINALS Consists of windings on a silicon steel core potted in a metal case. The mounting screws are electrically connected to the core and case.

Has terminals numbered 1, 2, 3, 4, 7 and 10.

Intended to operate over the frequency range of 700 to 1700 hertz.

Series aiding connections can be obtained by strapping terminal 2 to 3.

Closest recommended mounting centres are 1.750 inches by 1.750 inches.

Intended for use in the 598608 signalling supply for ac key pulsing in connection with telephone systems.

Approximate dc Resistance Winding (Ohms)

(l-2) 0.45 (3-4) 0.45 (7-10) 4500 MARCH 1971 NE-635A INPUT TRANSFORMER STANDARD

I

Solenoidal and duolateral windings assembled on a permalloy powder core, and potted with three capacitors, two inductors and a resistor in a metal case. An electrostatic shield is provided between windings (l-2) and (3-T-4) and is connected to terminal "S". A variable air capacitor is connected between terminals 3 and 6 and one of the inductors is connected between terminals T and 5. Has an impedance ratio of 72 to 500 + 9000 ohms between windings (l-2) and (3-T-4). Approximate dc resistance of windings (3-T) and (T-4) is 0.13 and 10.5 ohms, respectively. The dc resistance of winding (l-2) cannot be measured because a series capacitor is connected between one of the terminals and the transformer winding. Intended to operate over the frequency range of 312 to 552 kHz.

Closest recommended mounting centres are 1.750 inches by 3.500 inches. Intended for use in the S68774C transmitting and 568774E receiving intermediate amplifier panels in the L type carrier telephone system. MARCH 1971 NE-636A INPUT TRANSFORMER STANDARD

Consists of a transformer having layer and duolateral windings on a permalloy powder core. An electrostatic shield is provided between windings (1-2) (3-4) and (5-6) and is connected to terminal "S". A network consisting of capacitors, an inductor and a resistor connected between terminals 2 and 3. All of the components are potted in a metal case.

Has an impedance ratio, between terminals (l-4) and (5-6), of 125 to 2000 ohms at 420 kHz and 125 to 12,500 ohms at 612 kHz.

Intended to operate between a 125 ohm cable and the grid of an electron tube.

,.164”DIA. Closest recommended mounting centres are 2.625 inches by 3.500 inches. a fT-.f-T-? Intended for use in the 368775Y group carrier amplifier in the L type carrier system. Approximate dc Resistance Winding (Ohms) (l-2) 0.2 (3-4) 0.2 (5-b) 12.0 MARCH 1971 NE-637A INPUT TRANSFORMER STANDARD

Core type coil, having a permalloy powder ring core, potted in a metal case.

Has an impedance ratio of 144 to 4000 ohms between windings (l-2) and (3-4) and operates at single frequencies between 620 kHz and 2350 kHz when tuned with a variable capacitor across winding (3-4). The capacitor is part of the circuit in which this input transformer is used.

Has an electrostatic shield between windings (l-2) and (3-4).

Approximate dc resistance of windings (l-2) and (3-4) is 0.2 ohm and ----IX7 2.5 ohms, respectively.

Closest recommended mounting centres are 1.750 inches by 2.625 inches.

Intended for use in the J68775K amplifier of the super group carrier supply for the L type carrier telephone system. MAY 1972 SEE RATINGS NE-638 TYPE INPUT TRANSFORMERS BELOW

Intended for use in the 368806 regulators in the L type carrier telephone system. Closest recommended mounting centres are 2.062 inches by 2.062 inches. NE-638A: Double tuned air core type transformer incorporating a variable capacitor which is adjustable from outside the case, and a fixed capacitor. NE-638C: Double tuned air core type transformer incorporating a variable capacitor which is adjustable from outside the case, and two fixed capacitors.

Impedance Operates on Approximate Ratio Frequency dc Resistance Code (Ohms) (kHz) Winding (Ohms) Rating

(l-2) .06 NE-638A (a)4,000 to 160,000 2064 Standard I (3-4) 1.0 1 (l-2) (b) II NE-638C (a)2,000 to 100,000 64 I (3-4) 60. 1

(a) Between windings (l-2) and (3-4). (b) Due to capacitors in this transformer, there is no dc path between terminals 1 and 2. MARCH 1971 NE-640A INPUT TRANSFORMER STANDARD

Shell type transformer having a silicon steel core and potted in a metal case which provides magnetic shielding. The mounting studs are electrically connected to the core and case. Has an impedance ratio of 300 to 120,000 between windings (l-2) (3-4) and (5-6). Intended to be used in the frequency range of 200 to 3,000 hertz. Series aiding connections can be obtained by strapping terminal 2 to 3. Closest recommended mounting centres are 2.625 inches by 2.625 inches.

Approximate dc Resistance Winding (Ohms)

(1-Z) (3-4) in series 80 (s-6) 8,500 MAY 1972 NE-642A INPUT TRANSFORMER S'I'AWARU

Consists of a coil having an air core and enclosed in a metal case.

Intended to be used at single frequencies over the frequency range of 463,000 to 605,000 hertz.

Approximate dc resistance of windings (l-2) and (3-4) is 2.1 ohms and 1.5 ohms respectively.

,164" Dlpl Closest recommended mounting centres are 1.750 inches by 2.625 inches.

Intended for use in the J64031A transmission measuring set. MARCH 1971 NE-646 TYPE INPUT TRANSFORMERS (Card 1)

Each consists of windings on a silicon steel core and enclosed in a metal case.

\ TERMINAL NUMBERS ARE \ FOR REFERENCE ONLY Intended to mount on 1.250 inches horizontal centres s si 1 * I r -- 138’:32 TN0 and 1.750 inches vertical centres. However, where space is required above or below the input transformer for the adjustment of relays, the input transformer should be rotated 90' clockwise when viewed from the terminal end, and in this case 1.750 inches horizontal and vertical mounting centres are required. When ordering mounting plates for the latter arrangement, "Drill per Arrangement A" should be specified. MARCH 1971 I NE-646 TYPE INPUT TRANSFORMERS 1 SEERRAENGS (Card 2) NE-646B: Has an impedance ratio of 20,000 to 80,000 ohms between windings (l-2) and (3-4). NE-646C to F: Tntended for use in common systems amplifier voice operated gain equipment. NE-646C: Has an impedance ratio of 200 to 200,000 ohms between windings (l-3) and (4-5). NE-646D: Has an impedance ratio of 600 to 150,000 ohms between windings (l-3) and (4-5). NE-646E: Has an impedance ratio of 6,000 to 150,000 ohms between windings (l-2) and (3-4) (5-6). NE-646F: Has an impedance ratio of 16,000 to l,OOO,OOO ohms between windings (l-2) and (3-4). An electrostatic shield is provided between the windings and is connected internally to the core.

Approximate dc Resistance Frequency (Ohms) of Windings Range Code (l-2) (l-3) (3-4) (4-5) (5-b) (Hertz) Rating NE-646B 1300 3500 200-3000 Standard (a)(b)(d)NE-646C - 10.6 1800 300-3000 11 (a)(b)(d)NE-646D - 40 4590 200-4000 II (a)(c)NE-646E 840 1715 2480 200-4000 II (a)(e)NE-646F 1060 3800 200-4000 11

(a) Case contains a magnetic shield. (d) Terminal 6 is a dummy terminal, that is, has no (b) Terminal 2 is centre tap of winding (l-3). internal connection to it. (c) Series aiding connections can be obtained (e) Terminals 5 and 6 are dummy terminals, that is, by strapping terminal 4 to 5. have no internal connections to them. SEE RATINGS MARCH 1971 NE-647 TYPE INPUT TRANSFORMERS BELOW

Each consists of windings on a permalloy core, potted in a metal case. Intended to operate over the voice frequency range. Provided with an electrostatic shield which is connected to the core and case. Closest recommended mounting centres are 3.188 inches by 1.750 inches. NE-647B: Has terminals numbered 1 to 12, inclusive. Has impedance ratios of 600 + 600 to 160,000 ohms between windings (1-2) (3-4) + (5-6) and (9-10) (11-12) and 600 + 600 to l,OOO,OOO ohms between windings (l-2) (3-4) + (5-6) F&3 NUMBER OF TERMINALS, SEE TEXT and winding (7-8). Intended for use in the JY87OlB MlCl common carrier terminal of the Ml carrier telephone system. Works as part of a hybrid coil set with the NE-189C . NE-647D: Has terminals numbered 1 to 9 inclusive. Has an impedance ratio of 9,000 to 1,000 ohms between windings (7-9) and (l-3) (4-6). Terminals 2 and 5 are centre taps on windings (l-3) and (4-6), respectively. Terminal 8 is a tap on winding (7-9). Intended for use in the J98611A El telephone repeater in the exchange area plant. I I Approximate dc Resistance of Windings (Ohms) Code (l-2) (l-3) (3-4) (4-6) (5-6) (7-8) (8-9) (9-10) (11-12) Rating NE-647B 11.5 - 11.5 - 23.0 7000 - 890 890 Standard NE-647D - 18 - 18 - 250 270 - II MARCH 1971 NE-656A INPUT TRANSFORMER I

Consists of an input transformer and an output transformer, each having a shell type permalloy core, and potted together in a metal case. Equipped with flexible terminal leads. 19 r '6 - ~ OR*NGE Impedance ratio of the input transformer is 300 to 357,000 ohms ORINGL-WHITE between windings (Orange Orange-White) and (Yellow Yellow-White). , "'ELLOW j IELLOWWHLTE Impedance ratios of the output transformer are 600 to 18,800 ohms 1 RED RYD.'v4HITE between windings (Red Red-White) and (Blue Blue-White); 600 to 30 ohms I BLUE between windings (Red Red-White) and (Green Green-White), 600 to 43.5 ohms BLUE-WHlTE GRFFN between windings (Red Red-White) and (Brown Brown-White) and 600 to 20,000 ohms between windings (Red Red-White) and Blue Blue-White) (Green Green-White). Winding (Blue Blue-White) will carry 4 milliamperes dc. P Winding (Green Green-White) is a feed back winding and winding (Brown Brown-White) is a monitoring winding. Designed to operate over the frequency range of 200 to 3000 hertz. Approximate dc Resistance Winding (Ohms) (Red Red-White) 76.0 (Blue Blue-White) 1875.0 (Green Green-White) 62.8 (Brown Brown-White) 17.5 (Orange Orange-White) 16.8 (Yellow Yellow-White 6360.0 MARCH 1971 NE-659A INPUT TRANSFORMER STANDARD

Core type input transformer with a silicon steel core and enclosed in a metal case. Has a separate electrostatic shield around each winding. These shields are electrically separated from each other. The shield around winding (Blue-White Green) is connected to the core and case. Has an impedance ratio of 24,000 to 16 ohms between windings (Blue-White Green) and (Red Red-White) and 24,000 to 24,000 ohms between windings (Blue-White Green) and (Red-White Blue). Intended to operate over the frequency range of 300 to 3,000 hertz. Normally intended to mount on 1.250 inches horizontal centers and 1.750 inches vertical centres. However, where space is required above or below the input transformer for the adjustment of relays, the input transformer should be rotated 90' clockwise when viewed from the mounting end and in this case 1.750 inches horizontal and vertical mounting centres are required. When ordering mounting plates for the latter arrangement, "Drill per Arrangement A" should be specified.

Dimensions Approximate dc Resistance (Inches) (Ohms) of Windings A B (Red Red-White) (Red-White Blue) (Blue-White Green) 5.00 5.500 4.1 1825 1275 JUNE 1972 NE-661 A INPUT TRANSFORMER STANDARD

Core type transformer having a permalloy core and potted in a metal case.

Has an impedance ratio of 800 to 800 ohms between windings (4-5) (6-7) and (l-3). Terminal 2 is the centre tap of winding (l-3).

Intended to operate over the frequency range of 0.05 to 20 megahertz from the plates of push-pull 6AG7 electron tubes to the grids of push-pull 6AG7 electron tubes.

Provided with an electrostatic shield between the primary and secondary windings. The shield is connected to terminal "S". Closest recommended mounting centres are 1.750 inches by 2.625 inches. Approximate dc Resistance Winding (Ohms)

(l-3) 0.45 (4-5) 0.22 (6-7) 0.22 MARCH 1971 NE-663A INPUT TRANSFORMER STANDARD

Toroidal type coil having a permalloy core. Assembled in a hermetically sealed metal case. Coil is provided with an electrostatic shield between the windings. The shield is connected internally to the case. Has an impedance ratio of 110:2000 ohms between windings (l-2) and (3-4). Intended to operate over the frequency range of 50 to 4,000 kHz. Closest recommended mounting centres are 1.750 inches by 1.750 inches. Intended for use in the 568336 terminal equipment of the NTD-2 radio system.

Approximate dc Resistance Winding (Ohms)

(l-2) 0.30 (3-4) 12.0 MARCH 1971 NE-665 A INPUT TRANSFORMER STANDARD

Shell type transformer having a permalloy core and potted in a metal case.

Has an impedance ratio of 1:l:l between windings (l-2), (3-4) and (5-6).

Approximate dc resistances of windings (l-2), (3-4) and (5-6) are 3.7, 4.0 and 4.3 ohms, respectively. Closest recommended mounting centres are 1.688 inches by 1.594 inches. MARCH 1971 NE-666A INPUT TRANSFORMER STANDARD

Toridal type coil having a permalloy powder core and potted in a metal case.

Closest recommended mounting centres are 1.750 inches by 2.625 inches.

Has an impedance ratio of 600:360,000 ohms between windings (2-l) (6-5) and (4-3) (8-7). Provided with an electrostatic shield between windings (2-l) (6-5) and (4-3) (8-7), connected to terminal S.

Approximate dc Resistance Winding (Ohms)

(l-2) 0.2 (3-4) 5.5 (s-6) 0.2 (T-8) 5.5 JUNE 1972 NE-667 TYPE INPUT TRANSFORMERS SEE RATINGS BELOW I Each consists of windings on a permalloy core and potted in a metal case. Closest recommended mounting centres are 1.218 inches by 1.656 inches. Intended to operate over the voice frequency range unless otherwise indicated. NE-667A, B, & C: Initial use: J98703F channel unit of the NE-N1 carrier telephone system. NE-667A: Has an impedance ratio of 5000 to 664,000 ohms between windings (Red Red-white) to (Blue Blue-white). NE-667B: Has an impedance ratio of 600 to 10,000 ohms between windings (Red ‘138..-32TAPPED Red-white) to (Blue Blue-white) and 600 to 450,000 ohms between (Red Red- HOLES white) to (Green Green-white). NE-667C: Has an impedance ratio of 600 to 644,000 ohms between windings (Red Red-white) to (Blue Blue-white). NE-667E: Has an impedance ratio of 600 to 450,000 ohms between windings (Red Red-white) to (Green Green-white). Provided with an electrostatic shield between windings which is connected to the black lead. Initial use: J98703AM.

Approximate dc Resistance (Ohms) Code (Red Red-white) (Blue Blue-white) (Green Green-white) Rating NE-667A 750 5700 Standard ,I NE-667B 20 (a) ca, NE-667C 120 7000 I, NE-667E 18.4 4200 1, (a) Approximate dc resistance between Blue and Green leads, with Blue-white and Green-white leads connected together, is 6800 ohms. MARCH 1971 NE-668A INPUT TRANSFORMER STANDARD I I

Consists of special windings assembled on a toroidal type permalloy core and a solenoidal air core coil assembled in a hermetically sealed metal case. The special coil has two windings, one connected between terminals 3 and 4 and the other winding connected in series with the solenoidal winding between terminals 1 and 2.

Intended to operate over the frequency range of 60 to ,164” 3200 kHz.

Has an impedance ratio of 72 to 10,500 ohms between windings (l-2) and (3-4).

Approximate dc resistances of windings (l-2) and (3-4) are 1.5 and 28.0 ohms, respectively.

Closest recommended mounting centres are 1.750 inches by 2.625 inches.

Forms a part of the NE-219R filter and the 564033A transmission measuring set. MARCH 1971 SEE RATINGS NE-669 TYPE INPUT TRANSFORMERS BELOW

Each consists of multi-layer windings assembled on a permalloy powder core and potted in a metal case. , w.~sr THREAD $"OEEP Has an impedance ratio of 3,000 to 20,000 ohms between windings (l-3) and (4-6). Closest recommended mounting centres are 1.094 inches by 1.250 inches. NE--.669A & B: Intended to operate from 3,000 ohms filters and serve as input transformers for feedback amolifiers. NE-669B is also intended to ooerate as an outoutL transformer from an electron tube plate circuit into a germanium crystal bridge rectifier. Intended for use in the NE-N1 carrier telephone system. NE-669D: Same as NE-669A except it may not meet the reflection coefficient required for NE-669A. . . Approximate dc Resistance Frequency (Ohms) of Winding Range Code (kH;) (l-3) (4-6) Rating (a)NE-669A 44 to 140 96 300 Standard (a)NE-669B 164 to 260 23 76 $9 (a)NE-669D 44 to 140 96 300 (0

(a) Terminals 2 and 5 are dummy terminals, that is, have no electrical connections to them. MARCH 1971 1 NE-674A INPUT TRANSFORMER STANDARD

Consists of an input transformer having duolateral windings on a permalloy powder core, two inductors, a resistor and three capacitors potted in a metal case.

Approximate dc resistance between terminals 1 and 3 is 0.7 ohm and between terminals 4 and 5 is 100 ohms. Terminal 2 is a tap on winding between terminals 1 and 3. There is no electrical connection to terminal 6.

Provided with an electrostatic shield between windings of the input transformer. The shield is connected to terminal S.

Closest recommended mounting centres are 2.625 inches by 3.500 inches.

Intended for use in the .J68782D and 5687838 amplifiers in the K2 carrier telephone systems. When used in the above amplifiers, the transmission shapes are approximately the inverse of the loss of 12.8, 14.9 or 17.6 miles of 19 gauge aerial cable over the frequency range of 12 to 60 kHz. MARCH 1971 NE-675 A INPUT TRANSFORMER STANDARD

Consists of a core type coil having a silicon steel core, a duolateral wound coil, a resistor, and three capacitors potted in a metal case. Has an impedance ratio of 600 to 60,000 ohms between windings (l-2) and (3-4). Intended to operate over the frequency range of 12 to 60 kHz.

Provided with an electrostatic shield between windings (l-2) and (3-4). The shield is connected to terminal S.

Approximate dc resistances of windings (l-2) and (3-4) are 11 ohms and 760 ohms, respectively.

Closest recommended mounting centres are 1.750 inches by 2.625 inches.

Intended for use in the 5687848 amplifier panel and 5687886 amplifier in the K2 carrier telephone system. MARCH 1971 NE-676A INPUT TRANSFORMER STANDARD

Consists of two duolateral windings on a core tube of insulating material and covered with potting compound, a fixed capacitor and a variable capacitor assembled in a metal case. The fixed capacitor is connected between terminals 1 and 2. The variable capacitor is connected between terminals 3 and 4 and is adjustable from the terminal side of the input transformer.

Has an impedance ratio of 70,000 ohms to 600,000 ohms between windings (l-2) and (3-4).

Intended to operate at 56 kHz.

Approximate dc resistance of winding (l-2) is 30 ohms and of winding (3-4) is 380 ohms.

Closest recommended mounting centres are 2.625 inches by 3.500 inches. MARCH 1971 NE-677A INPUT TRANSFORMER STANDARD

Duolateral windings on a toroidal type permslloy powder core and r- potted in a metal case. 13" -f- Has an impedance ratio of 1 to 10 between windings (l-2) and (3-4). I $ 4-L Intended to operate at 5 kliz. The approximate dc resistance of winding (l-2) is 20 ohms and of winding (3-4) is 310 ohms. --%a--- Closest recommended mounting centres are 1.750 inches by 2.625 inches.

6 MARCH 1971 NE-680A INPUT TRANSFORMER I STANDARD

Consists of a transformer having a permalloy core, a capacitor and a resistor assembled on a metal bracket and wired to a terminal block and a standard 8 prong electron tube socket mounted on the bracket.

Intended to operate at 400 hertz.

Has a turns ratio of 8.7 to 1 between windings (BL-BL WH) and (RD-RD WH) of the transformer, and the approximate dc resistances are 5700 and 380 ohms, respectively. DECEMBER 1969 QTMIA INPUT TRANSFORMER STANDARD

t I ,531 Arranged to mount on a printed circuit board.

Has an imped.lnce ratio of 8 to 600 ohms between windings (6-5) and (2-3).

i)prrates over the frequency range of 300 to 3000 hertz.

Provided with electrostatic shield connected to terminal 4.

Nominal dc resistance of winding (5-6) is 1 ohm and of winding (2.-3) is 55 ohms. I ,562 Initial use: in QUMlB key telephone unit.

(a) Terminal numbers are fur reference only. DECEMBER 1969 QTM2A INPUT TRANSFORMER STANDARD

Consists of windings on a permalloy core potted in a metal case.

Has an impedance ratio of 23 ohms to 23 ohms between windings (l-2) and (3-4).

Operates over the frequency range of 300 to 3000 hertz.

Nominal dc resistance of windings (l-2) and (3-4) is 3 ohms each.

Initial use: Business inter-phone in conjunction with 3-type speakerphone systems.