SERVICE MANUAL 5707

INSTALLATION AlJD l·lAINTENA.t'jCE INSTRUCTIONS

for

NON-VITAL

AUDIO FREQUENCY OVERLAY (AFO) EQUIPr.'.IENT

FOR LINE APPLICATION

The information and data in this manual apply only to non-vital AFO equipment manufactured after October, 1958.

Section

I II

III IV v

VI Appendix

Ja.nuarJ, 197 3 e:o. 73-iM...,66:3.3

TABLE OF CONTENTS

Title

Introduction Principles of Operation Equipment Description Application and Installation Data Field Inspection and Servicing Shop Uaintenance Voltage Tables, Schematic Diagrams,

~est Circuits, Parts Data, and Dimension Drawings

Page

3 3 5

11 20 24

35

. WESTINGHOUSE AIR BRAKE COMPANY UNION SWITCH&. SIGNAL DIVISION Swissvale Post Office, Pittsburgh, Pa. 15218

An American-Standard Company

Fi;~. no. l 2 3

4 5

6 7 8

9

10

11 12

13 14 15 16 17 18 19

5707, :p. 2

LIST .·'OF ILLUSTMT.IO'NS

Title

AFO Operation Line Transmitter Typical Line Transmitter Schematic Diagram AFO Receiver Typical Receive:: Schematic Diagram Style VF Blocking Reactor Line Coupling Unit Lightning Protection, Line Leads Lightning Protection, Battery Leads A.FO Receiver Output Characteristics

T'i;;o-Indication Block Occupancy Transmitter shop Test Connections Receiver Shop Test Connections Transistor Lead Identification Line Transmitter Data Sheet Line Transmitter Components Line Receiver Data Sheet Line Receiver Components llounting Dimensions for AFO Receivers, Transmitters, and Style LCA Coupling Units

. p·a;ge

4 6

6 8

8 9

10

11

13

16

17

26 29 31 36 37 40 ~1

44

·"

SECTION I

INTRODUCTION

The Union Non-Vital Audio Frequency Overlay (AFO) equipment provides a simple method of adding a number of independent control circuits to existing line circuits, with no inter­ference between any of the circuits involved.

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A typical line circuit use of AFO is in providing a remote indication of block occupancy to a CTC machine. In this case, AFO transmits the information from the track relays over the block signal lines to a field coding station and can provide an additional control circuit with an operating range of 15 miles or more under favorable conditions.

SECTION II

PRINCIPLES OF OPERATION

A. The AFO circuit functions by introducing an audio­frequency tone from a transistor-type oscillator and amplifier {hereafter referred to as a transmitter) into the existing conductor system at any desired point. This tone is detected by a receiver, placed at a second point along the conductor system. The receiver amplifies the tone and rectifies it into a d-c control voltage, which is used to energize a con­trol relay. The relay remains energized as long as the tone is received, and is de-energized when the tone is removed or sufficiently reduced. See Figures lA through lC.

B. Interruption or reduction of the tone, accompanied by drop-out of the control relay, may be accomplished by any of the following methods:

1. By opening the conductor system with a switch or relay at any point between the transmitter and receiver, as might occur in a d-c line application. (Figure lB)

2. By opening the power input circuit to the trans­mitter. (Figure lC)

c. Both the transmitter and the receiver contain filters which effectively block both d-c and all a-c frequencies other than the frequency of the desired tone. Thus the existing signal circuits are not shunted when the AFO equipment is connected to the line circuit, and the AFO equipment is un­affected by the operation of the existing circuits.

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NOTES: \If llfllitr,

ti I~ 'ft t f fl I I I I 11

OPERATING

5707, p. -1

LINE CIRCUIT

FIGURE lA. RZLAY :ZNERGIZED

DC POWER SOURCE

DC POWER SOURCE

LINE CIRCUIT

~ CONTROLLED CIRCUITS

FIGURE lB. CONDUCTOR OPENED

TRANSMITTER

! DC POWER

SOURCE

STANDBY

FJGUFIE lC.

DC POWER SOURCE

LINE ClflCUIT

AFO RELAY

t I .. CONTROLLED ?:: CIRCUITS

DEENER Bl ZED AFO TONE

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SECTION III

EQUIPUENT DESCRIPTION

A. LINE TRAN St-UTTER FEATURES

1. ·AFO transmitters made for line circuit applications are available with any one of the following output frequencies: 1.0 KHz, l.5 KHz, 1.95 KHz or 2.7 KHz. The choice of frequency will depend upon several factors which will be discussed later.

2. All transmitters have the same overall dimensions of 8-3/16 11 x 9-1/4" x 4-11/16 11

, and are otherwise nearly identical in appearance (detailed dimensions are included in the Appendix) •

3. Line transnitters contain a potentiometer to adjust the·output level to any desired output from -10 to 20 DBM. This adjustment feature permits the reduction of the AFO signal level in the event of interference with nearby corrununication circuits, and will be discussed in detail in subsequent sections. The transmitter is designed to work into impedance loads of 600 ohms.

4. Transmitters require a norainal 10 to 12 volt d-c source of power. Power consumption is approxinately 0.4 watt.

B. TRA.l.""lSMITTER CIRCUIT DESCRIPTION

1. A typical transmitter schematic diagram is shown in Figure 3. Referring to Figure 3, transistor SCl is con­nected in a conventional oscillator circuit, in which Pl (of Tl) and C2 form the frequency-determining circuit, and P2 provides regenerative feedback. The value of capacitor C2 is selected to produce the desired frequency. Zener diode Zl regulates the voltage to SCl to compensate for supply voltage changes, which could otherwise cause large changes in trans­mitter output voltage.

2. The output of the oscillator is coupled to class A. amplifying transistor SC2 through the secondary windin~ of transformer Tl. A potentiometer capable of being screwdriver­adjusted through an input level range of -10 dbn to 20 dhm controls the input level to the amplifier stages.

3. Transistor SC2 in turn is coupled through driver transformer T2 to transistors SC3 and SC4, connected in push­pull. The latter transistors are operated as a class B amplifier for greater efficiency and higher output.

4. Capacitor C6, connected across the prinary of out­put transformer T3, is used to improve the signal wave form.

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5707, p. 6

FIGURE 2. LINE TRANSMITTER

R6

C4r-8 +L

C5

: PAOD~RS

I ti I "' ... _ ... II

'--------1·-L R8

-DC

FIGURE 3. TYPICAL LINE TRANSMITTER SCHEMATIC DIAGRAM

-tDC

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Its value depends upon the operating frequency of the trans­mitter. T3 provides the proper impedance transformation to match the output of the transistors to the desired load. The turns ratio of transformer T3 will be determined by whether the transmitter is designed for track or line application.

5. The output signal from the secondary of T3 is passed through a single frequency pass filter consisting of T4, C4 and CS to provide a low impedance to the AFO frequency and a high impedance to all other frequencies. The filter thus performs the following functions:

a. Blocks d-c or conventional a-c signaling frequencies which may be present in the track or line circuits, and thus avoids shorting or loading any existing a-c signaling or power circuits.

b. Prevents the passage of harmonics of the fundametaJ:'AFO frequency into the line or track circuits.

c. Blocks d-c by the action of the series capacitors, thus preventing the shorting of a d-c track or line circuit.

The values for the toroid T4 and for capacitors C4 and CS are determined by ti1e transmitter application {i.e., line or track) and by the frequency.

C. LINE RECEIVER FEATURES

1. AFO receivers are available with input frequencies of either 1. 0 KHz, 1. 5 KHz, 1. 95 KHz or 2. 7 KHz to r.iatch the selected transmitter frequencies.

2. A typical receiver is illustrated in Figure 4. All receivers have the same external appearance, and may be distinguished from one another only by their nameplates. Receivers have the same overall dimensions as the transmitters; see Figure 19. Each receiver has a screwdriver actuated sensitivity control, mounted on its top plate, to permit field adjustment of the external relay pickup and drop-out.

3. The line receiver has a relatively high input impedance of 600 ohms. Aside frora differences in coraponent values, the circuits of all receivers are essentially the same.

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FIGURE 4. AFO RECEIVER

D. RECEIVER CIRCUIT DESCRIPTION

1. A typical receiver schematic diagram is shown in Figure 5. The input signal tone generated by the trans­mitter is received from the line at terminals +Land -L, respectively. T3 and C4 form a filter having a very narrow bandpass characteristic. This filter thus blocks all d-c and a-c signals except the tone from the transmitter.

2. Transformer T2 matches the input impedance of grounded base transistor SCl to the impedance of the line. Potentiometer P, connected across the secondary of T2, provides a receiver sensitivity control, as previously described.

C4

T2 I RI I I I

Ill LILJ ,,

lln R2 R3 R4

+LOR IT -LOR 2T +DC -DC -R +R

FIGURE 5. TYPICAL AFO RECEIVER SCHEMATIC DIAGRAH

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·.

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3. The output of class A transistor SCl is coupled through Tl to the input of a push-pull class B amplifier, con­sisting of transistors SC2 and SC3. This amplifier is deliber­ately· "over-driven II to secure a square wave output for maximum power efficiency. The output is coupled through transformer T4 to a full-wave selenium rectifier, where the signal is rectified into d-c. The output of the rectifier is fed to terminals +Rand -R, for connection to the operating coil of an external relay.

4. The receiver requires a 10 to 12 volt d-c power source, connected to terminals +DC and -DC. Power consumption is approximately 0.4 watt.

E. BLOCKING REACTORS

1. Depending upon conditions existing at a given AFO installation, one or more Style VF blocking reactors may be required in addition to the transmitting and receiving equipment. The blocking reactor is essentially a low-pass device, which passes d~c and low frequency a-c, but offers a relatively high impedance at any AFO frequency. Blocking reactors are· available for line use having 27.5 ohms d-c resistance. Style VF reactors are housed in cases, measuring 4-5/16" x 7-7/8" x 3" overall, as illustrated in Figure 9.

i-14------7·f-, .. ------1 ji'~ ~-----7.------,

FIGURE 6. STYLE VF BLOCKING REACTOR

2. A blocking reactor is required in one lead of battery connections to line circuits which carry an AFO signal.

3. Line relay coils usually have sufficient induct­ance to block the AFO signals without the use of a reactor.

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Detailed instructions for use of the reactor will be covered in the Application Data and Installation Instructions section of this publication. See Table I for a tabulation of these units.

F. COUPLING UNITS

1. Style LCA coupling units are designed to pass the AFO signal, while blocking d-c and low frequency a-c. All coupling units are identical in external appearance, except for terminal arrangement and nameplates. Dimensions for all units are 9-1/4" x 4-11/16 11 x 8-1/4': See Figures 7 and 19. Also see Table I for a tabulation of these units.

2. Line coupling units are principally used in transferring the AFO signal from one line circuit to another, as wo'uld be necessary in the block occupancy indication application. See Figure 11. Other circuits carried in the lines are not affected by the use af the coupling units.

3. The standard line coupling unit exhibits high­pass characteristics. It blocks d-c, provides considerable attenuation to 60 and 100 Hertz a-c and little attenuation to frequencies above 500 Hertz. An additional line coupling unit is also available for special applications, which passes the 1,000 Hertz AFO frequency and rejects all other frequencies and d-c. See Table I for a tabulation of the line units.

FIGURE 7. LINE COUPLING UNIT

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SECTION IV

AFO APPLICATION AND INSTALLATION DATA

This section contains the circuit design and equipment install­ation data required in planning and detailing an AFO install­ation. Standard practice for signaling circuits may be assumed in all cases unless otherwise specified.

A. GENERAL INFORMATION

1. FAIL-SAFE APPLICATIONS. The AFO applications discussed in this literature are for non-vital service, where failure of the AFO equipment will not result in an unsafe condition.

2 . POWER REQUIREMENTS • Each AFO transmitter and each receiver requires a nominal 10 to 12 volts d-c source and consumes 0.4 watt. However, they may be operated from 9 to 15 volts d-c in continuous service, and up to 18 volts d-c for several hours at a time. Due to the low power consumption, primary batteries may be used if desired.

3. LIGHTNING PROTECTION. Particular attention must be paid to lightning protection for an AFO installation. Lightning damage can occur from surges entering the AFO units through the line terminals or through the battery terminals. These terminals must be protected as follows:

a. LINE TERMINAL PROTECTION. The line terminals of each AFO transmitter and receiver should be protected by both series and shunt lightning arresters, as shown in Figure 8, references 1 and 2:

(1) The series arresters, reference 1, should be style USG arresters, with red marking. Either UN327988 (without terminal block) or UN327989 (with molded terminal block) may be used. This arrester has a minimum breakdown rating of 500 peak volts and a maximum rating of 1200 peak volts.

LINE CIRCUI T

' I © ' I © ,. i

0 I - - 0..:::. / -.c._ L. ... L__

AFO AFO

TRANIMITTER RECEIVER

0 3

References: See Text FIGURE 8. LIGHTNING PROTECTION, LINE LEADS

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(2) The shunt arresters, reference 2, should be style USG arresters with black marking. Either UN314265 (without terminal block) or UN314266 (with molded terminal block) may be used. These arresters may be used with existing line voltage of up to 30 volts. They have a minimum break­down rating of 50 peak volts and a maximum rating of 300 peak volts.

(3) Ground connections, reference 3, should be made to the common low voltage ground bus system that includes grounds at cases or houses. Make ground connections and jumpers with ft6 AWG wire. .Messenger wire or metallic sheath of cable if used, may serve as tie-in between cases or houses.

TABLE I

ORDERING REFERENCES

NON-VITAL AFO EQUIP.MENT FOR LINE APPLICATION

Name

· Transrni tter Receiver Transmitter Receiver Transmitter Receiver Transrni tter Receiver VF Blocking Reactor

LCA Coupling Unit

LCA Coupling Unit

Lightning Surge Suppressor

Series USG Arrester Series USG Arrester Shunt USG Arrester Shunt USG Arrester

5707 I l,'.)• 12

Piece Number

UN331880 UN331881 UN332722 UN332723 UN334306 UN334216 UN336282 UN336283 UN331859

UN334229

UN331857

UN382641

UN327988 UN327989 UN314265 UN314266

Frequency Characteristics

1000 HERTZ 1000 HERTZ 1500 HERTZ 1500 HERTZ 1950 HERTZ 1950 HERTZ 2700 HERTZ 2700 HERTZ

Blocks all AFO. Passes d-c and low frequency a-c.

Passes all AFO. Blocks all lower frequency a-c and d-c.

Single pass of 1000 HERTZ. Block all other a-c and d-c.

Without Terminal Block With Terminal Block Without Terminal Bloclc With Terminal Block

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b. BATTERY TERMINAL PROTECTION

(1) We recommend that the surge suppressor unit UN382641, be installed to protect AFO units even though the lightning surge entering the case can reach the battery terminals before.reaching the AFO DC supply terminals. The surge suppressors should be connected as shown in Figure 9.

(2) The lightning surge protection of Figure 9 consists of a separate USG Shunt Arrester with black markings, UN314266, reference 1 (with molded terminal block} or UN314265 (without molded terminal block) and a Lightning Surge Suppressor, UN382641, reference 2 •

. 3r 3f---i ------=ht---,-

... a~ ~N

+DC~

BATTERY BUS -

©

I" TO OTHER LSS UNITS

B .,/ 'N @

/~

+DC -~-, !---- '--DC

~ " TO OTHER (NON - VITAL) A FO UNITS

+DC AFO UNIT -oc TRANSMITTER OR

ti.'? RECEIVER

fL

LINE CIRCUIT

FIGURE 9. LIGHTNING PROTECTION, BATTERY LEADS

The USG nected as indicated in Figure bus and the surge suppressor. to the surge suppressor.

Shunt Arrester should be con-9, that is, between the battery It should be installed adjacent

(3) Up to four transmitters or four receivers (or any combination of four) can be protected by one surge suppressor.

(4) If two or more lightning surge sup­pressors located in a signal case are connected to the same battery bus, only one USG Shunt Arrester is required to pro­tect the AFO units. The single USG Shunt Arrester should be connected, as shown in Figure 9, between the battery bus and

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the nearest surge suppressor and located as near to this su~ge suppressor as practical.

(5) Operation of the lightning surge sup-pressor, arrester combination is as follows: · ·

The Zener diode used in this lightning surge suppressor is a constant voltage device. A low value lightning surge of reverse polarity will pass through it in the high resistance direction when the surge voltage reaches the avalanche or break through voltage of the diode, thus limiting the surge voltage which can be applied to the AFO units. If the surge voltage is greater than the breakdown voltage of the USG arrester, the choke coil will delay the buildup voltage across the Zener diode (and capacitor) until the arrester flashes, after which the voltage across the arrester drops substantially to zero. For a surge voltage of opposite polarity, the Zener diode is normally conductive and will prevent an excessive voltage rise across the transistors.

(6) The capacitor used in the lightning surge suppressor assists in holding down the surge voltage across the AFO units and in filtering the DC supply voltage.

4. OPERATING FREQUENCIES. For single installations, it is advisable to use 1000 HERTZ equipment as standard. The use of higher frequency equipment should be reserved for in­stallations requiring two or more AFO systems on a common circuit. f.iaintenance work and parts procurement will be simplified if this practice is followed.

5. RELAYS FOR USE 'WITH AFO. The following Union Switch & Signal relays are recommended as being suitable for operation by an AFO receiver:

5707, :p. 14

-, '

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TABLE II

RECOMMENDED RELAYS FOR AFO

Coils Power Style Resistance Required Piece

No. Contacts (Ohms} (Milliwatts} Number

PN150 6F-6BLV 400 81.5 UN322500-001

DNll 4F-4BLV 100 25.4 UN16199 7 250 27.2 UN159996 500 24.5 UN157285

1000 28.0 UN157187 2000 30 .4 UN157184

DNll 6F-6BLV 500 47.0 UN159871 1000 53.3 UN158263

DNll 8F-8BLV 500 60.5 UN159870

DN22A 2F-2B 100 13.0 UN224126 250 14.02 UN224129 500 12.5 UN239397

1000 14.3 UN224890 2000 15.54 UN224382

KP 2F-2B 1070/1070 45 .15 per coil UN191481

CD-F 2F-2BLVSP 225 100 UN373201 Non-Tuned lF-lBLVSP (22 .61-1.W when 180 Code coils are in

series or mul-tiple)

P-4 lF-lBSP 270 27.0 UN232637

P-4 2F-2BSP 270 69.0 UN236638

Figure 10 shows the AFO line receiver power output with variation in load (relay coil) resistance. This represents the minimum output power that can be expected on any receiver that has a sensitivity equal to or better than the value out­lined in Figure 17. If it is desirable to use a relay that is not listed above, the power required to operate that relay should be checked against the power output of the receiver as shown in Figure 10.

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(/) .... ~ 3 ::J ...I

~

.... ::::> 0... .... ::::> 0

0:: I.LI 3 0 0...

0 c:i

5707, :l?• 16

100

90

80

70

60

50

40

30

20

10

0

I

I I

OHMS MILLIWATTS LOAD POWER

RESISTANCE OUTPUT

100 33 200 55 270 67 300 71,5 400 81

.500 83 600 78 700 71.5 800 66 900 60,5

1000 56.5

I , :\~

OHMS MILLIWATTS LOAD POWER

RESISTANCE OUTPUT

1100 52 1200 48.5 1300 46.5 1400 43.5 1500 41.5 1600 39 1700 37.5 1800 36 1900 34 2000 33

I I I I I I I RECEIVER OUTPUT ADJUSTED TO 5,7 VOLTS ACROSS 400 OHM LOAD (FROM T.C.4420) -+--+---+----1

200 400 600 800 1000 1200 1400 1600 1800 2000

100 300 500 700 900 1100 1300 1500 1700 1900

O.C. LOAD (RELAY COIL} RESISTANCE ,OHMS

FIGURE 10. AFO RECEIVER OUTPUT CHARACTERISTICS

---.,,,

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B. APO LINE CIRCUIT APPLICATION FOR CTC

One of the principal applications of APO to line circuits has been to provide a block occupancy indication to a CTC machine. This application is presented in detail as a typical example, to illustrate the use of the equipment and the problems which may be encountered.

1. TWO-INDICATION CIRCUITS. Figure 11 illustrates an application of APO for providing two indications of track occupancy between CTC head blocks. The transmitter is located approximately in the middle of the CTC block, and is connected across the automatic block signal line wires. Each pair of line wires is coupled to the next pair by line coupling units, to pass the APO tone without affecting the signal circuits. Blocking reactors are installed in all battery leads, to prevent nshorting" of the APO signal. An APO receiver is con­nected to· 'the line at one end of the CTC block, and a second receiver for the same frequency is connected at the other end.

SIGNAL CON OL LINE

tL -L

AFO RECEIVER NQI

+ R -R

CODED CIRCUIT

~11111111 I I •1 11111111111~

:: FIELD CODING STATION '"':'----""" : N~l :

/011111111111111,1,1,,111,:=

OPERATING t'c:JtlffHUI .. IUI::

: E :,, ....... , .. :

NOTE:

B N

,!>.11111111Jllllltllfllf:

OFFICE DECODING

EQUIPMENT - --:,,,,. t 1111 Ill I I I IIIU;:'

CTC OPERATING PANEL

CODED CIRCUIT

STANDBY DEENERGIZED AFO TONE

B N

\I

FIELD CODING STATION NO.Z

FIGURE 11. TWO-INDICATION BLOCK OCCUPANCY

2. TWO-INDICATION OPERATION. When the CTC block is unoccupied, all of the track relay contacts will be closed and the AFO tone will be transmitted to both receivers. These in turn will keep both APO relays energized. When a train is

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anywhere in the area between Receiver 1 and the Transmitter, a pair of track relay contacts will be open between the Transmitter and Receiver 1, thus keeping Receiver 1 relay deenergized. Track occupancy between the Transmitter and Receiver 2 likewise will keep that receiver's relay deenergized. Relay contacts of the receiver are connected to the field coding stations at their respective location. Here the track occupancy information is coded and sent to the central office with the other CTC information.

3. SINGLE INDICATION BLOCK OCCUPANCY. If only one occupancy indication between head blocks is desired, one receiver and one transmitter are required. The transmitter in this case is connected to the line at one end of the CTC bloci{, and the receiver is connected at the other. The require­ments for coupling units and blocking reactors are the same as for a two-indication application. The presence of a train at any point within the CTC block will keep at least one set of track relay contacts open, thus removing the AFO tone from the receiver and deenergizing the AFO relay as before.

4. I-iULTIPLE BLOCK INDICATIONS. vn1en more than two block occupancy indications are required for a CTC block, two or more transmitters, operating on different frequencies may be used.

5. I1AXII-1UM LINE CIRCUIT LEUGTHS. The maximum length of line (pair) that can be used for AFO depends principally upon the following:

a. TRANSMITTER OUTPUT LEVEL. When only d-c, signaling and a-c power lines are found on the same poles as the AFO circuits, the transmitter can be operated at the maximum level (there is no problem of overloading the receiver). Where telephone or carrier communications lines occur on the same poles, the transmitter level should be reduced to the minimum level necessary for good performance. This is recommended to prevent pick-up of the AFO tone by the commun­ications services. Transposition of the lines carrying AFO is also recommended to eliminate interference.

b. ATTENUATION OF attenuation is 0.2 db per mile. of 40% copperweld ~HO open wire weather.

THE LINE. The usual maximum This represents the attenuation

pair, spaced 8 inches in wet

c. ATTEUUATION OF LINE COUPLING UNITS AND REACTORS. Each 0.5 KC high-pass coupling unit attenuates the AFO signal by approximately 0.5 db. The attenuation of the 1.0 KC single pass line coupling unit is approximately 2.0 db. The loss of AFO signal through the VF blocking reactor at each battery location is approxinatley 0.2 db per location.

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d. RECEIVER SENSITIVITY SETTING. The receiver has a maximum sensitivity of -10 dbmwith the sensitivity con­trol turned full clockwise. The highest sensitivity setting which may be used at any one installation is limited' only by the level of interference that may be picked up from adjacent circuits.

NOTE: DBM

Where v2 = Transmitter output voltage

and v1 = Voltage across 600 ohms to dissipate 1 milliwatt (.774 Volts)

6. LINE DROPS AND CASE WIRING. Line drops for AFO circuits must be made with a twisted pair. It is not necessary to use a twisted pair inside the signal cases.

7. AFO CIRCUITS ON ADJACENT WIRES. Where two AFO circuits occur on the same pole line, different frequencies may have to be used for the two systems. This is particularly important for long circuits.

8. DirIBHSIONS A.L"\JD rmuHTING DATA. The transmitters, receivers, coupling units and blocking reactors may be mounted in available signal cases in any position desired. If possible, the equipment should be mounted to provide a clear view of the terminals and nameplates. See Figure 19 for mounting dimensions.

9. CONNECTIONS A.L"\JD ADJUSTMEIJTS • Connection and checkout of the equipment should proceed as follows (for one transmitter and one receiver).

a. Connect all Line Coupling Units and Blocking Units to the line circuits as required.

b. Using a d-c voltmeter check that the supply voltage used for the receiver or transnitter is between 9 and 15 volts.

c. Connect the supply leads to the receiver, at terminals +DC and -DC. Observe correct polarity.

CAUTION

The equipment may be damaged if power is applied to the wrong terminals.

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d. Connect the line circuit to the receiver at terminals +Land -L (polarity is not significant).

e. Connect the AFO relay to receiver terminals +Rand -R. Observe correct polarity.

f. Loosen the lock nut on the receiver output control (Figure 4) and verify that the control is in the full clockwise {maximum output) position.

g. Using a d-c voltmeter of at least 10,000 ohms­per-volt sensitivity, check the +Rand -R terminals on the receiver for 0.1 or less volts. This check should be made with the maximum length of line in use (all track relays closed), and transmitter disconnected from the line.

h. If the residual voltage measured in (g) above is more ,.than O .1 volt, turn the receiver output control counterclockwise until the voltage drops to 0.1 volt.

i. Tighten the output control locking nut. Then check the voltmeter to see that the control has not shifted.

j. Connect the line wires to the transmitter at terminals +Land -L. Polarity is of no consequence.

k. Using a d-c voltmeter, check that the trans­mitter power source is between 9 and 15 volts.

1. Connect the transmitter the power source and adjust the output level to the level required to operate the receiver.

CAUTION

The equipment may be damaged if power is applied to the wrong terminals.

The receiver relay should pick up when the transmitter is energized, to the proper level.

SECTION V

FIELD INSPECTION AND SERVICING

This section contains the information necessary for routine inspection and for determining the causes of failure or faulty operation of the equipment in the field. Repairs to

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transmitters, receivers and other components should not be attempted in the field. A defective unit should be replaced and returned to the shop for servicing. Shop servicing infor­mation is provided in Section VI.

AFO troubleshooting may be accomplished in two ways. The maintainer may take test equipment with him to make input and output voltage measurements of the AFO receivers and transmitters. Or, he may carry a spare transmitter and receiver which are in good working order, and substitute these in turn for each unit of an installation, until the faulty unit is found.

A. FIELD TEST EQUIPMENT. A basic requirement for AFO field inspection and maintenance under either plan noted above is a d-c voltmeter for checking the battery supply voltage (i.e., 0 to 20 vol ts, or more) • Where an extra transmitter and recetyer of the proper frequency may be taken to the installation requiring maintenance, no other test equipment will be needed. Where an extra transmitter and receiver are not available, the following test equipment will be required as indicated:

1. One d-c voltmeter, 10,000 ohms per volt minimum sensitivity, 0-2.5-10-50 volt ranges.

2. One a-c multitester, 1000 ohms per volt minimum input impedance, with a 0-2.5 (or lower) range.

NOTE

Where a PD-20 (or PD-30) code meter is available it may be substituted for both of the above instruments, provided that a blocking capacitor is kept in series with one lead when measuring a-c.

B. PERIODIC INSPECTION. It is impossible to predict or guard against failure of the units by periodically testing them in the field. The equipment is not subject to mechanical wear, and deterioration of the electrical components is not ordinarily detectable in advance of failure. For these reasons, the inspections shown below are all that are required. They may be performed on whatever schedule the railroad deems necessary.

1. Visually inspect the units for the condition of the cases, terminals and wiring.

2. Check the lightning arresters to determine that they are in operating condition.

3. Using a d-c voltmeter, check the battery voltage for 9 to 15 volts.

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C. LINE UNITS FIELD SERVICING

The checking procedures are based on the assumption that the lines and its principal circuit are operating normally.

1. EQUIPMENT SUBSTITUTION METHOD. The following method of determining the cause of faulty operation may be used when a spare transmitter and receiver of the correct frequency are available. The method should be performed in the order shown.

a. RECEIVER CHECKS

(1) Using a d-c voltmeter check the receiver battery for a reading of 9 to 15 volts.

(2) Check the receiver output control lock­nut for ,-tightness. Readjust the control only if it has shifted due to vibration.

(3) Substitute a spare receiver of the correct frequency for the original receiver, and check for pick-up of the AFO relay. If the relay picks up the trouble is in the receiver. If the relay does not pick up, proceed with the next step.

(4) Connect the spare transmitter to the battery, and connect the line terminals of the original receiver to the output terminals of the spare transmitter. If the relay picks up, the trouble is in the transmitter or in the circuit between the transmitter and receiver. Re­connect the original receiver to the line. If the relay does not pick up, the trouble is in the relay.

b. TRANSHITTER CHECKS. When the receiver checks (above) indicate difficulty with the transmitter, perform the following checks at the transmitter. A man equipped with a field telephone should stand by at the receiver.

( 1) Using a d-c voltmeter, check the trans­mitter battery for a reading of 9 to 15 volts.

(2) Replace the original transmitter with the spare unit. If the receiver relay then picks up, the original transmitter is defective. If the receiver relay does not pick up, trouble is in the circuit between the two. A damaged line coupling unit, blocking reactor, shorted or open line may be the cause.

2. VOLTAGE HEASUREMENT METHOD. As an alternative to the foregoing, the receiver and transmitter input and output voltages may be measured to determine the condition of these units. Use the test equipment listed in subsection A, above. Proceed as follows:

5707, p. 22

a. RECEIVER CHECKS

(1) Using a d-c voltmeter, check the receiver battery for a reading of 9 to 15 volts.

(2) Using the 10,000 ohms-per-volt d-c voltmeter, raeasure the receiver output voltage at terminals +R and -R for a value equal to the miniraum picJ<:-up voltage of the relay, or higher. If this voltage is correct, the difficulty will be in the AFO relay, rather than in the transmitter or receiver.

(3) If the reading taken in (2) above, shows low voltage, or no voltage, check the receiver output control lock nut, to determine whether vibration may have loosened it and shifted the control. Readjust the control only if this has happened.

WABCD ~

(4) If receiver output voltage is not ob­tained by the above step, connect an a-c vacuum tube voltmeter (or appropriate substitute as specified in A) across terminals +Land -L. If a minimum of 0.3 can be read, the receiver is probably at fault, and should be replaced. If no-voltage or a low voltage reading is obtained, leave the receiver in service and check the transmitter.

NOTE

It is possible that the line may be picking up induced voltage frora ad­jacent 60 or 100 cycle power lines, especially when the signal line is not adequately transposed. This possibility should be kept in mind v·1hi le checking the receiver line terminal voltage.

b. TRANSIUTTER CHECKS

(1) Examine line drop for possible breaks.

(2) Using a d-c voltmeter, check the trans­mitter battery for a reading of 9 to 15 volts.

(3) Disconnect the line from transmitter terminals +Land -L. Using an AC voltmeter, check the trans­mitter +L and -L terminals for voltage. No exact reading can be specified for a no-load condition, but the reading should be considerably greater than 7.74 volts with potentioneter at its maximum output setting.

5707, J?- 23

WABCO ~

{4) With correct battery voltage, and a low­vol tage or zero voltage indication occurring in· { 3) above, the transmitter is defective and should be replaced. With adequate transmitter voltages, look for a damaged coupling unit, line blocking reactor, open or shorted line.

SECTION VI

SHOP MAINTENANCE

Any maintenance work requiring opening the cases of the AFO units should be done in the shop, rather than in the field. This section describes the shop procedures for test, over­haul and final inspection of the AFO units, and lists the test equipment required.

A. SHOP REPAIR AND TEST FACILITIES

1. POWER SOURCE. A 14 volt d-c power source is required for test operation of the equipment. This higher source voltage necessitates the use of a potentiometer to reduce the voltage to 10 volts. The potentiometer should have a total resistance of 350 ohms or less.

2. TEST EQUIPr.iENT. The follrn·ling test equipment is recommended for shop testing and servicing the AFO units:

a. A d-c voltmeter which includes ranges of 0-10-50 volts and has a minimum sensitivity of 10,000 ohms per volt.

b. A d-c milliammeter with ranges of 0-50 milli­amperes, and either 0-500 milliamperes or 0-1 ampere.

NOTE

A U.S. & s. Code Heter, Model PD-20, (Model PD-30 or Hodel PD-10) is recommended as a single instrument for both the voltmeter and milliammeter requirements.

c. An ohmmeter capable of measuring from 1 to 100, 000 ohms. A "megger" must not be used, as the high volt­age used could damage the AFO components.

d. One a-c vacuum tube voltmeter, 0.1 megohm minimum input impedance, with 0-10 millivolt, and 0-1-3-10-30 volt ranges.

5707, p. 24

WABCD ~

e. A frequency counter covering the AFO range (1 KC through 2.7 KC), readable to within ±1 cycle, with an accuracy of ±0.1%. This counter will be used to set the frequency of the AFO units. A set of spare AFO units, known to be in good condition, may be used instead of the frequency meter as a frequency standard. The spare units must be for the same frequency as units to be calibrated.

f. An audio frequency oscillator with a range of up to 3 KC.

g. Three fixed resistors in larger, either composition or wire wound. 400 ohm are required. These are used for mitters and receivers during test.

half watt size or One 600 ohm and one

loading the trans-

h. An adjustable audio frequency matching transformer, to be used in matching the audio oscillator out­put to the line receivers inputs. The turns ratio required is 8:1 for line receivers. A U.S. & S. Style W-10 traclc transformer may be used for this purpose.

i. An oscilloscope (optional).

j. A spare AFO transmitter and receiver of the same frequency and type (i.e., track or line), is recommended for use as test equipment. They may be employed to advantage for transistor testing by substitution.

3. TOOLS. Tools required will be soldering iron, long nose pliers, and a screwdriver and an AAR socket wrench.

B. TRANSf.lITTER REPAIR

When repairing line transmitters first adjust the output level to the maximum position. Transmitters having different frequencies will differ only in the values of certain components. The following procedures apply to all transmitters, except where othenvise specified:

1. Remove the four screws at the corner of the trans­mitter top plate and lift the transmitter out of its case:

a. Examine for visible damage, loose connections, signs of arcing, etc.

b. Particularly note the condition of resistor Rll. If it appears to have been overheated, charred or burned, then either or both of transistors SC3 and SC4 have probably failed also. Resistor Rll is designed to operate as a fuse for the output transformer as well as a current limiter. Thus it must be replaced only with another one-half-watt, 10-ohm resistor.

5707, l?• 25

WABCC ~

c. Replace resistor Rll if required. Then proceed to step 2.

2. Connect a 600 ohm, half-watt resistor across the output terminals +Land -L. Set the VTVM to the Oto 10 volt range and correct it across the 600 ohm resistor.

3. :Make the battery, milliammeter and switch connections as shown in Figure 12. Set the milliammeter at the 0-1 ampere range.

reading. 4. Close the switch momentarily and note the current

CAUTION

If the current drain is over .050 ampere, open the switch immediately.

+DC 600 OHHS

ACVM = A.C. VOLTMETER FM= FREQUENCY METER A= D.C. AMMETER

SEE TEXT FOR DETAILS OF ABOVE

FIGURE 12 . TRANSIUTTER SHOP TEST CONNECTIONS

a. HIGH CURRENT DRAIN. If the current reading is considerably higher than the normal .040 ampere, one or both of the output transistors, SC3 and SC4 are probably faulty. (First, see Figure 14 and paragraph D, 1 through 4.} Then replace the transistors one at a time, rechecking the current after each change. If the current is reduced to approximately .04 ampere by this procedure check the output voltage and compare with the values shown in Figure 15. If the output voltage is within the tabulated values, the frequency of the transmitters should be checked, and, if within allowable limits, the unit should be inspected per paragraph F, Hechanical Inspection.

5707, p. 26

CAUTION

To avoid damage to transistors, follow the procedure in paragraph D-2,for soldering or unsoldering leads.

b. NORMAL CURRENT DRAIN. If the original current reading is normal and the output voltage is low, connect the frequency meter to the output terminals +Land -Land note the frequency.

WABCCI ~

(1) If the frequency is more than S cycles from the correct value, one of the capacitors of C2 probably has a broken lead or is partially shorted. Unsolder one end of each and test individually. Use an ohmmeter in high sensitivity position when checking for shorts. Replace any defective,,capacitors with new ones of the same values. Recheck the frequency. It may be necessary to replace one or more of the smaller value capacitors with either a higher or lower value to bring the transmitter to the desired frequency. The permissible tolerance is +5 cycles.

(2) If the frequency as originally measured in b, above, is correct, turn off the transmitter, and con­nect the ohmmeter (in high sensitivity position) across the output terminals. If the reading shows any value other than open-circuit, one of the capacitors in C4 or CS has failed. Isolate the defective capacitor and replace it by the method described in (1) above. Turn on the transmitter and note the output voltage. Then replace the smallest value capacitor in CS with one of a larger value and remeasure the output voltage. If the voltage has increased, try a still larger capacitor until the maximum output is attained. If the volt­age has decreased, remove capacitance from CS until maximum voltage is attained.

(3) If the initial checks in (2) above show that C4 and CS have not failed, check a-c voltages outlined in Figure 15. Front and rear views of the transmitter showing location of components have been provided in Figure 16 so that location points for measurement of voltage can be readily located by use of these views and schematic diagrams.

c . VERY LOW CURRENT DRAI:tJ. If the current drain is .010 ampere or less, the trouble is probably in the oscillator circuit. This condition could also be due to a burn-out of Resistor Rll as discussed previously.

5. INTER11ITTENT OPERATION. If nothing can be found wrong with a unit reported to have failed in the field, a close examination should be made of all soldered connections

5707r J?· 27

WABCO ~·

for a rosin connection or an unsoldered terminal. If nothing is revealed by this examination, the resistor and capacitor components should be moved slightly out of position with the fingers while noting the input current and output voltage reading. If this reveals nothing, the d-c voltage supplying the unit should be increased to 15 volts if possible and the· unit turned on and off several times to see that the oscillator is properly starting. If it fails to start, the difficulty is probably in the oscillator transistor SCl. Check SCl as directed in paragraph D, 1 through 4.

C. RECEIVER REPAIR

The general procedure for servicing line receivers is the same. The only difference between models for all frequencies is the values of certain components. The following procedures apply to ail receivers:

1. Remove the four screws at the corners of the receiver top plate and lift the unit out of its case.

a. Visually inspect the components and wiring for loose or broken connections, signs of overheating and arcing or other damage from lightning.

b. Particularly note the condition of resistor Rl. If it appears to have been overheated, charred or burned, then either or both to transistors SC2 and SC3 have probably failed also. Resistor Rl is designed to operate as a fuse for the output transformer as well as a current limiter. Thus it must be replaced only with another one-half watt 10 ohm resistor.

c. Replace resistor Rl if necessary, then proceed to step 2.

2. Loosen the receiver output control lock nut and turn the control to its maximum clockwise position. Connect the receiver to the test oscillator through the audio trans­former as in Figure 13, using the turns ratio noted on the figure. Likewise, connect a-c voltmeter and the fr~quen~y meter as shown. Connect the 400-ohm output resistor and the d-c output voltmeter across output terminals +Rand -R. Con­nect the milliammeter (0-1 ampere scale or higher), the switch and the battery to terminals +DC and -DC. Keep the switch open. Energize the test oscillator only, and adjust the output for a reading of Vl volts (per Figure 17) as read on the AC voltmeter. Tune the oscillator until it is exactly non-frequencyc1

, as shmvn on the frequency meter.

5707, p. 28

AUDIO OSCILLATOR

A<:;VU •_)\ •. C •. _VOLTHETER F!-1.:: FREQUENCY METER.

A .:: D .C. .AHMETER VDC .:i D. C • VOLT!·tETER. . t

T.:: AUDIO TRANSFORMER TURNS RATIO:

90; 1 :FOR TRACK UNITS I· I· 8; 1 :FOR LJ;NE UNITS +IOV

~EE TEXT :FOR DETAILS 0:F ABOVE

FIGURE 13. RECEIVER SHOP TEST CONNECTIONS

3. Momentarily close the receiver battery switch and note the current.

CAUTION

If the current drain is over .050 ampere, open the switch immediately.

a. HIGH CURRENT DRAIN. Where the current reading is higher than .040 ampere, one or both of the out­put transistors SC2 and SC3 have failed. First, see Figure

WABCCI ~

14 and paragraph D, 1 through 4. Then replace the transistors one at a time, rechec](ing the current after each change. If the current returns to approximately .035 ampere, connect the voltmeter to the output terminals +Rand-Rand note the input voltage Vl required to obtain 5.7 volts output as shown in Figure 17. If the input voltage required to give this value of output voltage is high, proceed with the checks in b, below.

CAUTION

A transistor can be damaged by heat during soldering. See Paragraph D-2 of this section for correct procedure.

b. NORJ:.fAL CURRENT DRAIN. If the current reading is normal and the input voltage is high, check the voltages

5707, J?· 29

WABCD ~

indicated in Figure 17 to localize the trouble. Front and rear views of the receiver showing location of components have been provided in Figure 18. Location of points for measurement of voltages can be readily located by use of component views and the schematic diagrams.

c. LOW CURRENT DRAIN. If the current reading is very low (.010 ampere or less), check resistor Rl for an opened condition. If this has occurred, either SC2 or SC3 transistor, or both, will also have failed. Replace the resistor and the faulty transistor(s) and check for normal current consumption and output voltage. If Rl has not burned out, proceed as follows:

1. Unsolder one lead of each of the cap­acitor units of C4 and test with an ohmmeter in high sensiti­vity pos~.tion. If any reading is obtained, replace the capacitor unit with another of the same value. Resolder all leads. Turn the receiver potentiometer c omterclockwise until the output reading is approximately 1 volt. (This places the receiver at a sensitivity position best suited for checking tuning.) Remove the capacitor section of C4 having the lowest value and replace it with a somewhat larger capacitor. Check the output voltage for an increase. If it has decreased, replace the capacitor section with one having less capacity. Continue changing capacitance to favor a voltage increase until the maximum voltage is produced. Reset the potentiometer control to its maximum clockwise position.

2. If voltages across T3 and C4 were found to be equal, when measured in (1) above, or the capacitor uni ts of C4 are not shorted, check the condition of transistor SCI, as shown in paragraph D, 1 through 4.

d. INTERf.1ITTENT OPERATION. If nothing can be found wrong with a unit reported to have failed in the field examine all soldered connections closely for "rosin jointsn or unsoldered terminals. If nothing is revealed by this examination, move the resistor and capacitor components slightly out of position with the fingers while noting the input current and output voltage reading. If this reveals nothing, increase the d-c voltage supplying the unit to 15 volts and turn the unit on and off several times to see that it functions properly. If it fails to function, the difficulty is probably in one of the transistors.

5707, :p. 30

D. TRANSISTOR CHECKS

WABCD ~

1. WHEN TO REPLACE TRANSISTORS. A transistor should not be replaced unless the tests shown in 4, which follows, give some indication that the transistor has failed or is deficient. An intermittent fault elsewhere may clear up temporarily at this point, only to cause failure again when the unit has been returned to service.

2. SOLDERING TRANSISTOR LEADS. When soldering or unsoldering a transistor lead, grasp the lead with pliers between the transistor and the joint while applying heat. Otherwise, the transistor may be damaged by heat conducted by the lead.

3. TRANSISTOR LEAD IDENTIFICATION. Figure 14 shows the body and leads of a transistor, with the leads referenced to a PNP_ ,transistor circuit symbol. Note how the individual wire leads may be identified by the spacing between them. The correct lead connections for installing a new transistor may be found by comparing this figure with the schematic of the unit being serviced.

2N44 2NS24

B ; 2N44

0 E B C

BOTTOM VIEW

FIGURE 14. TRANSISTOR LEAD IDENTIFICATION

4. TESTIHG TRANSISTOR. The following procedures may be used for checking AFO transistors where special testing equipment is not available.

a. BREAKDOWN. Transistor breakdown may readily be detected by using a high sensitivity ohmmeter. Remove the transistor from the circuit. Connect the positive ohm­meter lead to the joint emitter and base terminals, and the negative lead to the collector. The resistance should measure

5707 r 1?· 31

VVRBCCI

~·~

between 70,000 and 160,000 ohms. If the reading obtained is considerably below 70,000 ohms, replace the transistor. These values are intended only as a guide. Considerable variance in readings will be found among transistors in good working order, as indicated. Discard the transistor only when the readings exceed the tolerances by a wide margin.

b. GAIN. The best gain test for a questionable transistor is to install it in the push-pull output stage of a spare AFO unit known to be in good condition. The output of the unit should be noted before and after the substitution. This provides a dynamic operating check that is superior to the results given by a transistor tester.

E. I1AINTENANCE PARTS.

1. Complete parts lists for all AFO units are given in the Appendix. The part symbol references for any one unit are the same on the parts lists, the schematic diagrams and on the components sheet. A part reference found from any one of these sources may thus be quickly located in the other two.

a. For example, the reference symbol for a resistor in a line transmitter can be found on the Line Trans­mitter Data Sheet, Figure 15. Suppose it is R4. By locating R4 in the Line Transmitter Parts List, the resistor value is found to be l.5K (1500 ohms) and the ordering reference is UJ721064. The identification of the resistor may be double­checked by locating R4 on the Line Transmitter Component views, Figure 16.

F. FINAL INSPECTION. Upon completion of the necessary repairs, perform the following inspections:

1. iillCHAtJICAL HJSPECTION

a. Inspect all component mounting screws and nuts for tightness. Replace any hardware lost during servicing.

b. Check all wiring for loose connections, loose solder particles and shorted terminals.

c. Check all transistors for proper seating in their mounting clips.

d. Be sure that no component part protrudes past the edge of the mounting board.

2. ELECTRICAL INSPECTION

a. Perform the voltages and current measurements shown in Figures 15 or 17 as applicable.

5707, •i?· 32

WABCCJ ~

APPENDIX

A. INTRODUCTION

Following are voltage tables, schematic diagrams, parts lists, parts illustrations and mounting dimensions for AFO units.

B. GENERAL

The maximum and minimum readings shown in the voltage tables are indicative of the typical manufacturing spread encountered and are intended as a guide in searching for faults in the unit.

Higher readings than the maximums shown may be obtained on some units and generally should not be taken as an indication that the unit is not operating properly except in the case of input voltage reading on the receiver.

Slightly'" lower readings than the minimums shown will generally be caused by loss of gain in the transistors. If the measured values are no more than 20 percent below the minimum value shown, it is recommended the unit be left in service.

C. TR.ANSI.UTTERS

1. Transmitters are set by adjusting the output voltage Vg to relatively narrow limits across a fixed load. This allows the voltage spread on various units to be small near the output portion of the transmitter. This spread, however, will become increasingly large (due to compiling of variations) toward the front or oscillator end of the trans­mitter.

2. The Zener diode network in the transmitter func­tions to reduce the change in output voltage with change of battery voltage. It can be checked by varying the d-c input to the transmitter from 9 to 13 volts and noting that the corresponding change in a-c output volts is 25 percent or less.

D. RECEIVERS

1. Receivers should be checked by placing the receiver potentiometer in the maximum clockwise position and increasing the input voltage until 5.7 volts is obtained across a 400 ohm load connected to +Rand -R. Under this condition, the required input should not exceed the maximum V1 values given in the voltage tables. As with the trans­mitters, a large spread exists between maximum and minimum values at the front end of the receiver. This results from some receivers possessing an input sensitivity voltage well below the maximum value given. For field application, the sensitivity of all receivers can be made the same, if desired, by adjusting the potentiometer control.

5707, ];)· 33

WABCD ~

2. The V1 volts on some receiver units in gray cases where 2N45 transistors were employed in the push-pull output stage may be somewhat higher than the values shown in the voltage tables.

5707, p. 34

VOLTAGE TABLES

SCHEMATIC DIAGRAMS

PARTS LISTS

PARTS ILLUSTRATIONS

MOUNTING DIMENSIONS

WABCD "'V'A,../'

5707, l?· 35

WABCO

"-"'•"V' .

SCI

21

SCHEMATIC DIAGRAM

-DC -L +L

+DC INPUT 1 SW. VOLTAGE L----.,-..:::::~:::::::::::=--------+----r-(-) !..ll~~~-__!~:#=-==-----.---~600-"­

4000 MFD" _ 50 W VDC 12 TO 14

+ VDC

D. C. AMMETER 0-150MA

RANGE

Test Vl Point Min.

!KC UN331880 3.8

Note II A II 4.3

V2 Max. Min. Max.

5.1 .002 .005

4.85 .0035 .009

'----'-(+) ELECTRONIC FREQUENCY COUNTER

TEST CIRCUIT

VOLTAGE TABLE

VAC

V3 V4 vs Min. Max. Min. Max. Min.

3.1 3.9 .52 .64 6.0

3.6 4.9 .59 • 72 6 .9

\ VTVM

H.P. MOD. 4000 OR EQUIVALENT

V6 V7 Max. Min. Max. Min.

7.8 9.6 12.2 94

7.7 11.5 12. 4 95

Max.

142

140

LOAD RES.

VB Min.

89

95

Max.

138

113

--VAC----.,.1 VDC -, r-vAC, rAJAP----,

Test V9 VlO Vll Vl2 Vl3 Vl4 Vl5 1dc Point Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max.

lKC U1'1331880 7.85 8.75 10 .o 10.0 6.3 7.0 .17 .56 .20 .27 .22 .29 .029 .047 .035 .040

Note "A" 7.9 8.2 10 .o 10.0 6.1 6.9 .35 .41 .19 .23 .21 .27 .032 .046 .035 .040

I:Tote "A" Applies to 11332722 (l.5Kc), 1133~306 (l.95ICc) and

11336282 (2. 7I~c)

FIGURE 15. Line Transmitter Dat~ Sheet

5707, :P• ~6

;FIGU~ 1:6.

VIEW LOOK ING AT TOP (I" I.ERM\~ SOARD

Line Transmitter Components

WR.BCD

~

5707, l?· 37

vv .-,111:::ILii...... ·

""""~ CAPACITORS

U.S. & s. REF. MFD. TOL. % VOLTS PC. NO. USED ON

Cl 100 +100 25 UJ70826 All -10

C2 .04 7 ±20 100 UJ702278 lKC See .015 ±20 200 UJ702281 1 and 2.7KC Note .027 ±20 100 UJ702276 1.5 and 1.95KC "A" .0005 ±2 500 UJ700712

.001 ±2 500 UJ700612

.002 ±2 500 UJ700614 >All .003 ±2 500 UJ700616

.005 ±2 500 UJ700618 C3 100 ±100 25 UJ70826 All

-10 C4 .015 ±5 2500 UJ700840 lKC

.006 ±5 2000 UJ700 732 1.5 & 1.95KC

.005 ±2 2000 UJ700536 2.7KC cs

: .. ,. .001 ±2 2500 UJ700933

k11 See .0005 ±10 2500 UJ701916 Note .0002 ±10 2500 UJ701913 "A" .0001 ±10 2500 UJ701912 J C6 .1 ±10 400 UJ701526 lKC

.05 ±20 400 UJ701573 1.5 & 1.95 KC

.02 ±20 400 UJ701723 2.7 KC (two)

.01 ±20 400 UJ701926 1.5 KC

Note PA" - Units are tuned by means of capacitors C2 and CS which are made up from values shown.

TRANSISTORS

U.S. & s. REF. TYPE PC. NO. USED ON

SCl 2N44 (UJ7 30754) ALL SC2 or SC3 SC4 2N524 UJ721073

DIODE

u.s. & s. REF. TYPE PC. NO. USED ON

Zl 1N754A UJ723882 ALL

· 5707, :P• 38

.."

POTENTIOMETER RES. U.S.& S

REF. OHMS. TOL. % WATTS PC. NO. USED ON p 50 ±10 2 UJ62297 All

RESISTORS RES. U.S.& S

REF. OHMS TOL. % WATTS PC. NO. USED ON Rl l.5K ±10 0.5 UJ721064 All R2 l.5K ±10 0.5 UJ721064 All R3 l.5K ±10 0.5 UJ721064 All R4 l.5K ±10 0.5 UJ721064 All RS lOK ±10 0.5 UJ720883 All R6 620 ±5 0.5 UJ721253

470 ±5 0.5 UJ721065 390 ±5 0.5 UJ720763 220 ±5 0.5 UJ720887 180 ±5 0.5 UJ720824 Use as re-

; .. ,. 120 ±5 0.5 UJ72101 quired to 100 ±10 0.5 UJ73742 >adjust out-

51 ±5 0.5 UJ720129 put level. 30 ±5 0.5 UJ720004 20 ±5 0.5 UJ720066 10 ±10 0.5 UJ73818

RS 300 ±5 0.5 UJ720141 All R9 240 ±5 0.5 UJ73733 All RlO 2.4K ±5 0.5 UJ721255 All Rll 10 ±10 0.5 UJ73818 All

TOROID INDUCTORS INDUCTANCE M.H. ±1.5%

1st 2nd 3rd U.S. & s. REF. WINGING WINDING WINDING PC. NO. USED ON

Tl 381 1.8 .041 UN39669 3 1 & 1. 5KC 187 1.1 .03 UN396695 l.95&2.7KC

T4 1500 --- --- UN396 716 1 & l.5KC 1000 --- --- UN396 718 l.95KC

600 --- --- UN396719 2.7KC

TRANSFORMERS REF. TURNS M'l' J.U U.S.&S. PC.NO. USED ON

T2 PRI to SEC 1 5.2 to 1 UJ730548 All SEC 2 5.2 to 1 T3 PRI 1 SEC .62 to 1 UJ331876 All PRI 2 to .62 to 1

Line Transmitter P~rts Li~t tcontinued}

5707, I?• 39

Wl,=IBC:::D

"V'4V

T3 It

C4

I · I PAOOER

I I L~~-.J

v· 7

SC2 SCI

RI

Va

SC3

V7

+L L SCHEMATIC DIAGRAM

-DC -LTURNS RATIO ,.,,,8:_'.,__I ----~ +DC

+L

1 UNl56455 VARIABLE

Ill FREQUENCY ..------+-M-A-T~CHING OSCILLATOR

TRANSF. ,

VTVM H.P. MOD. 4000

OR EQUIV.

Test POint

lKC UiBJ1881

1.SKC U,~332723

l.95KC UNJJ4216

2.7KC Ur1336283

· ELECTRONIC FREQUENCY MEASURING SYSTEM ~ 2 CYCLES

-VAC

Vl V2 Min. Max. Min. Max.

.095 .28 .60 .90

.077 .177 .78 .92

.165 .198 • 75 .87

.074 .098 .68 .91

VAC

VDC

Min.

.75

.BJ

.88

• 79

1

D.C. AMMETER 0-150 MA RANGE WESTON MOD. I

OR EQUIV.

TEST CIRCUIT

VOLTAGE TABLE

VJ V4 vs Max. Min. Max. Min.

1.05 8.4 9 .a· .0023

1.29 7.9 9.9 .0023

1.00 9·.1 9.7 .0035

.96 9.0 9.2 .0030

VDC

Test VB V9 · VlO vu Vl2 Point J,tin. Max. Min. Max. Min. Max. Min. Max. Min.

!KC UN33188l .51. .74 7.3 8.9 10.0 10.0 5.7 5.7 .20

l.5KC UN33272 3 .22 .84 7.0 8.25 10.0 10.0 5.7 5.7 .19

1. 95KC UW334216 .56 .64 7.75 8.3 10 .o 10.0 5.7 5.7 .20

2.7KC UWJJ6283 .59 .67 8.0 8.65 10 .o 10.0 5.7 5.7 .20

floe +oc + v10 -oc

VAC

V6 V7 Max. Min. Max. Min.

.0067 3.0 4.2 6.8

.0053 2.8 3.75 6 .6

.0053 J. JS J.65 7.2

.0044 3.28 3.95 7.5

~AMP---,

Max. Min:dcMax.

.27 .030 .035

.26 .030 .035

.24 .030 .035

.26 .030 .035

Figure 17. . . Line Receiver Data Sheet

5707 r J?• 40

+R

4 /

LOAD RES .

-R

D.C. VOLTMETER 0-15V RANGE

WESTON MOD. 901 OR EQUIV.

Max.

8.2

8.0

7.8

8.2

I

l= __

fIGURE :L8.

VfE• LOOK I Na AT TOP OI' :JEIIMINAL aoMo

Tl

0.

0.

"'

2S

T2 I

._____LJ ----

Vil• LOOKIN• AT WNelllSIDE 0,

TEIIIIINAL ao•D

L~ne Rece~ver Com~onent~

5707, 1?· 41

WABCO

~·~

REF. C2

C3

C4

See Note "A"

p

A D D E R s

! MFD. i 100

100

.002

.001

.0005

.00082

.0005

.0003

.0002

.0001

.00005 • 0-000 3 .00002 • 00001

CAPACITORS

U.S.&S. TOL. % VOLTS PC. NO. USED ON

+100 25 UJ70826 All -10 +100 25 UJ70826 All -10 ±10 2500 UJ701921 lKC(two) 1.5

and 2.7KC ±10 2500 UJ701951 1.5 & l.95KC ±10 2500 UJ701916 l.95KC ±10 2500 UJ701919 ±10 2500 UJ701916 ±10 2500 UJ701914 ±10 2500 UJ701913 ±10 2500 UJ701912 Use as ±10 2500 UJ701910 >Required ±10 2500 UJ701909 ±10 2500 UJ701908 ±10 2500 UJ701907

Note "A" - Units are tuned by means of capacitor C4 which is made up from values shown.

POTENTIOMETER RES. U.S.&S.

REF. OHMS TOL. % WATTS PC.NO. USED ON p 100 ±10 2 UJ62298 All

RECTIFIERS

U.S. & s. REF. PC. NO. USED ON

RCl UN321733-001 ALL

TRANSISTORS

U.S. &.S. REF. TYPE PC. NO. USED ON

SCl 2N44 UJ730754 SC2 or ALL

SC3 2N524 UJ731073

Line ~cceivcr:: Parts Li;3t

5707, p. 42

RESISTORS RES. U.S.&S.

REF. OHMS TOL. % WATTS PC. NO. USED ON Rl 10 ±10 0.5 UJ73818 All R2 300 ±5 0 .5 UJ720141 All R3 240 ±5 0.5 UJ73808 All R4 2.4K ±5 0.5 UJ721255 All

TOROID INDUCTORS INDUCTANCE M.H. ±l.5%

1st 2nd 3rd U.S. &S. REF. WINDING WINDING WINDING PC. NO. USED ON r3 5700 --- --- UN396717 !KC

3600 --- --- UN396720 1.5 & l.95KC 1500 --- --- UN396716 2.7KC

TRANSFORMERS U.S.&S.

REF. TURNS RATIO PC. NO. USED ON Tl SEC 1 3.2 to 1 PRI 1 to SEC 2 3.2 to 1

UJ730548 All

T2 PRI to SEC 0.6 to 1 UN331877 All T4 PRI ~ to SEC

0.86 to 1 UN332481 All PRI 0.86 to 1

Line ~eceiver rart~ List (Continued)

5707, p. 43

WABCO

~·~

5707, p. 44

I" 2

ri t "' v

r! t..~.J

i"'"\ fJ L,

r ., I I

(4)!" 32

11n,. HOLES

I" 4

8~" 16

ALL TERMINALS, ALL UNITS

Figure 19 . . Mounting Dimensions for AFO Receivers, Transmitters, and Style LCA Coupling Units