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Western Electric 407A-4 Instruction Manual

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  • Page 2 WEST ELECTRIC 407A-4 RADIO SMITTING EQUIPMENT Ins tructi ons For Us e Preliminary Instructi on Bulletin No . 946P...

  • Page 4: Table Of Contents

    WESTERN ELECTRIC RADIO TRANSMITTING EQUIPMENT 407A-4 Instructi ons for Use CONTENTS INTRODUCTI ON DESCRIPTI ON OF APPARATUS General ± Main Transmitter As s embly Equipment in 50-kw Encl osure Equipment in 5 Enclosure Equipment Outs ide Enc losures DESCRIPTION AND ADJUSTiiENT OF C IRCUITS...
  • Page 5 General Installation Notes To Drain System C ompletely To Fill System Automatic Drainage of Cool ing Units Adjus tment of Water-Cooling System RADI O-FREQUENCY CIRCUITS D-99110 Os cillator Amplifier Circuit Desc ription Os cillators F irst Radio-Frequency Amplifier Stage S ec ond Radio-Frequency Amplifier Stage Third Radio-Frequency Amplifie r Stage Audio Amplifier Power-Supply C ircu its...
  • Page 6 Adjustments for 5-kw Emergency Output STARTING THE TRANSMITTER Preliminary Rectifier Filaments Os c i llator-Ampl ifier Filaments Water System .Amplifier Filaments High-Voltage C ontrol 5-kw Emergency Operati on SWITCH FUNCTIONS Os cillator-Ampli fi er Modulating-Amplifier Power-Ampl ifier Control Unit Power Equipment Water System LAMP FUNCTI ONS Operation Lamps...
  • Page 7 Magnet Contacts Maintenance Motor-Operated C ircuit Breaker - Maintenance Daily Monthly o r After 20 Overload Oper ations TABLES No . 1 - Unit A - Typical Meter Readings No. 2 - Unit A - Plate, Screen and Fil ament Voltages No .

  • Page 8: Introducti On

    �07A-q RADIO TRANSMITTING EQUIPMENT IN' r RODUCTION The 407A-4 Radio Transmitting Equipment consists es s en­ tial ly of the following : a quartz -crystal control led oscil­ lat or operating into a three-stage radio-frequency ampli­ fie r ; a three-stage audio-frequency amplifier; a modulating ��plifier having two water-cool e d tubes in paralle l ;...

  • Page 9: Descripti On Of Apparatus

    grid-bias supply equipment t o b e switche d out of c ircuit and the e qu ipment operated at 5-kw carrier power, us ing the pre­ ce ding radio-frequency s tage modulated stage as the output amplifi er . This is an as surance against lengthy program in­...

  • Page 10: Circuit 6

    sure " within which are install e d the high voltage rec ­ 50 -kw tifier, filter choke and condens ers and grid b ias r ecti fier encl osure " within which is the correspond­ unit ; and a 115-kw ing power equ ipment for operati on, inc luding the...

  • Page 11: Main Transmitter Assemb Ly

    The letters ass igned to the units and assembl ies of apparatus are : Unit A - D-99110 Oscillator - Amplifier Unit C - D-151135 Modulating Amplifier Units D and E - D..;9 9118 Power .Amplifier Unit F - Special D-99116 Contro l Unit Unit G - Special D- 99114 Rectifier Unit Unit H - D-9911 9 Rectifier Tube Unit Unit J - .Antenna-Coupl ing Unit...

  • Page 12: Equipment In 50-Kw Encl Osure

    transmiss i on l ine to the antenna-coupling unit, and the coaxial harmonic shunt line , connect d irectly to the output terminals of this power amplifier. The maj or ele­ ments of the control system which suppl ies power in the proper sequence to the various parts of the equipment, to­...

  • Page 13: Equipment Outside Enclosures

    connection), comprising the three-phase plate rectifier. also includes a single-phase full-wave rectifier, supplying grid voltage to the two tubes in Unit for emergency operation at 5-kw. Power Distribution Cabinet (DP50P): This unit contains contactors, disconnect switches ann circuit breakers for the various 460-volt circuits of the transmitter, filament start­...

  • Page 14: Description And Adjustiient Of C Ircuits

    Auxil iary Voltage Regulator (T57P ) : This is an auto­ matic regulator controlling a constant-potential a-c bus from which all filament and b ias vol tages , and the plate voltages in the preliminary stages, are derive d . Auxiliary Power Distribution Cabinet (DP51P): This unit contains two power c ontactors supplementing thos e in the main cabinet DP5oP.
  • Page 15 and 103 of this unit to the cir cuit breaker CB51P, which is equipped with b oth thermal and instantaneous magnetic over­ load tripping device s and provides for manually disconnect­ ing al l power from the transmitter and also for emergency overl oad protection.
  • Page 16 preliminary stages are derive d. CB55P and contactor S51P control the app lication of power to the cooling-unit mot or s . Selection of the unit :MBl . lW or l1Bl . 2W is controlled by the pos itions of D4. 1W or D4.

  • Page 17: D-99119 Rectifier Tube Unit

    plate transformer T58P during 5-kw emergency operation. S63P and S64P are contactors which transfer the 460- volt output of the Plate Regulator between the high-voltage transformers T53P, T54P, T55P for 50-kw operation T58P for 5-kw emergency operation These contactors are located in auxiliary power distri bution cabinet DP51P.
  • Page 18 unidirectional current which after being filtered by choke coil L51P and condenser C51P is connected to the anode cir­ cuits of the 298A water-cooled amplifier tubes. The seventh tube, V7H, with its anode and filament both connected to busses, is provided for use in case of failure of any of the other tubes.
  • Page 19 a tube arcs back, an alternating current flows through the shunt associated with the faulty tube and current flows through the copper-oxide rectifier and associated relay, thus opening the relay contacts and giving an indication on the control panel of the particular tube which has arced back.

  • Page 20: Tub E Filament Adjus Tment

    The operation of each relay SlH to S6H may then be checked by connecting the secondary winding of one of the filrunent transformers TlH to T6H momentarily a cross the shunt associated with the respective relay. The relay should operate when this is done. A further check may be made to determine the condition of the copper-oxide rectifier by ap­...
  • Page 21 ( Note paragraph marked "Caution" below. ) checked by the following means. rectifier tube VlH with its current coil ( 10-ampere coil ) in Connect a wattmeter into the circuit of the 460-volt winding of TlH; also connect an ammeter ( 0-10- series with the anode of VlH and its potential coil across ampere scale ) in series with the current coil of the watt­...

  • Page 22: C Ircuit Des Cription

    The direction of rotation of the blower motor will be reversed at each change of phase connection to terminals 34, 35 and 36, but this can be corrected at the motor terminals. ( U nit K, Schematic Figure 3 ) D-99120 Bias Rectifier Unit Circuit Description Three rectifiers for supplying bias voltage to the...

  • Page 23: Special D-99114 Recti Fier Unit

    The other three-phase half-wave rectifier consists of power-supply transformer T8K, filament transformer T7K, 249B vacuum tubes V8K, V9K and VlOK, choke coil L6K, load resistor R3K - R4K, and voltmeter multiplier R5K with its protector PRlK. It supplies approximately 1200-volts d-c for biasing the grid of the 298A tube V2D of the D-99118 power amplifier.

  • Page 24: Special D-99116 Control Unit And Cont Rol C Ircuits 1

    sive current drawn from the rectifier and to open the high­ vol t a ge circuit breaker. R esistance R2G may be used to ad­ just the operate point of this relay. Protection from accidental contact with the high-volt­ age circuits of the rectifier and other apparatus within the main enclosure is afforded by the mechanically interlocked switches DlG, D2G, and D3G, which are operated by a hand­...

  • Page 25: Oscillator-Amplifier 1

    control circuits which extend throughout the system. This unit provides independent control of the oscillator ampli­ fier, of the water system and amplifier filament circuits, and of the rectifier-tube filaments and bias rectifiers. The high-voltage control is interlocked with these branches. With this control circuit, preheating of mercury vapor rec­...
  • Page 26 230 volts through terminals 3F, and 5F to terminal 6 of dis tribution pane l DP50P. This energiz es contactor S54P, which supplies power from terminals 1 1 6 and 117 of DP50P to D2A and D3A are normally in the " ON1 1 terminals 3A and 4A.

  • Page 27: Rectifier Filaments And Bias

    tactor S58P. The operation of S58P energizes the power am­ plifier filaments through the s tarting res istors R51P, R52P and R53P. A s the filaments heat up, increasing in resis ­ tanc e , the proportion of the supply voltage appearing acros s the f ilament trans formers also increases .

  • Page 28: Bias Rectifiers

    description of the operation of Sl6F, which controls the re­ heating of the rectifier tubes i n case of power failures, is given under the paragraph "Power Interruptions. 11 Under orig­ inal starting conditions Sl6F will operate and close its con­ tacts on terminals 3 and 4 about 18 seconds after Sl6F is energized.

  • Page 29: Powe R Interrupti Ons 2

    and S64P (5-kw) , one branch returning to DllF and the other to e ither S 56P ( 50-kw) or S55P ( 5-kw). The former branch is connected through DllF in the " Operate " pos ition to terminal 2 6F, then to terminal lOA and through D4A and 15A t o 137F, through D5F, 133F and 16A to the relay S3A which applies power to the high-voltage rectifier in the oscillator ampl i­...
  • Page 30 sufficient voltage to be maintaining the current between the electrodes through R2, the relay Sl will operate immediately. If, however, C2 has discharged to such a value that the tube is no longer conducting between the electrodes when the power is reapplied, C2 must be recharged to the value neces­ sary to break dowtl the tube.

  • Page 31: High Voltage

    ments is controlled by Sl6F, and the delay is proportional •. to the length of power interruption High Voltage The high-voltage control cir cuit is common with the amplifi er filament control from D2F through SlF and D3F to S 53P. At this point the high-voltage control is connected in serie s through the auxiliary contacts of S53P, S59P, and S56P...

  • Page 32: Emergency Plate Circuit Breaker

    the operate coil of Sl2F are deenergized and S9F is released. Thro ugh 60F, relays Sl3F and Sl4F are energized. Sl4F extin­ guishes lamps E27F "Circuit Breaker Open" and completes the circuit of S50F to the positive of the 24-volt relay circuit. Sl3F, a delay relay, operates after 2 seconds to energize S61P and S67P, the contacts of which short-circuit the charg­...

  • Page 33: Overload Tripping Circuit

    the a pplication of high voltage, and it is the responsibili ty Circuit Breaker CB73P will now be the control of of the operator in charge to make sure that all personnel are out of the enclosure, that all gates are closed, and that the tr?ll s mitter is ready for the application of h igh voltage before CB73P is closed.

  • Page 34: Plate Regulator

    connected across the 24-vol t supply through 11Lamp Reset" key K3F. The lamps are energized from the secondary of T2F through the lamp contact of each relay. Protective Circuit The protective relay S3D operates to close its contacts when any change occurs to disturb a balance between the in­ put and output circuits in the power amplifier.

  • Page 35: Os Cillator-Amplifi Er C Ontrol

    Os cillator -Ampl ifier Control If for testing or s ervicing it is d es ired to operate the o s c illator-ampl ifier unit switch DllF ma.y be thr own t o the " TEST " pos it ion. This acts t o open the gat�...

  • Page 36: Mis Cellaneous C Ircuits 2

    TDlF. Water-Cooling System General The distilled-water cool ing system of the 407A-4 Radi o Transmitt ing Equipment is designe d to maintain the tempera­ ture of the water-cooled vacuum tube s within safe limits . The syst em is s imple in principle ; as shown diagrammatically...
  • Page 37 age current meter which indicates the current to ground (MSF) through the water. The s afety devices for the protection of the vacuum tub es cons ist of an alarm-operating the rmometer TDlF warn of the approach of the water temperature t o a safe high limit, and water flow relays which serve (WDlW...

  • Page 38: Installation Notes

    are obtained b y s eparate control of the cooler b l owers and by manipulation of the by-pass valve Zl8W The safety by­ pass valve WZ lW protects the cooler radiator s from exces ­ s ive head pres sure and the vacuum tube s ockets from exc e s ­ s ive back pres sure .
  • Page 39 Start first pump MPl. lW and observe for proper direc­ tion of rotation. The pump stuffing boxes should be allowed to leak about twenty drops per minute for the first half hour, and thereafter about five drops per minute. Turn pump outlet valve Z2.
  • Page 40 Open inlet drain valves Z5W and Z6W and inc rease set ­ tings of throttle valves Z3W and Z4W to full open. After five minutes, open outlet drain valves Z 9W and ZlOW and close drain valves Z 5W and Z 6W. After five minutes, open isolating valves ZllW and Zl2W and close drain valves Z9W and ZlOW.

  • Page 41: To Drain System Completely

    operati on, and if necessary, adj usted as des cribed in sepa­ rate instructions . Finally, the system should be drained, refi lle d with distilled water, and adjusted for normal s erv­ ic e operation. To Drain System Completely Open the following : Waste valve Z22W Auxiliary pump valves Z 2 5W and Z 26W...

  • Page 42: To Fill System

    To Fill System First close the following : Tank outlet valves Z21 . 1W, Z 21 . 2W Waste valve Z22W Aux iliary pump valves Z 2 5W , Z 26W Drain cocks Z 2 C , Z7W Pump outlet valves Z 2 . 1W, Z 2 . 2W Drain valves Z 5W, Z6W, Z9W, Z lOW Then open is olating valves Z lC , Z llW, Z l2W and b y-pass valve Zl8W .
  • Page 44 Valves Fully Open Valves Fully Closed Tank Inlet 2 20 . lW or 220. 2W Tank Inlet 2 20 . 2W or 220.lW Tank Outl et 2 21 . 2W or 221.lW Tank Outlet 2 21 . lW or 2 21 . 2W C ocks on gau ges M4W , M5W, M6W M7W, MSW, MlOF Two s ide valves on manifo l d...
  • Page 45 Close cooler drain valves 215. lW and 215. 2W after viater has drained from cooling u nits. Starting in freezing weather Before starting, have yalves and switches set as speci­ fied above for stopping : Cooler inlet valves 214. lW and 214. 2W closed. Cooler drain valves 215.

  • Page 46: Radio-Frequency Circuits

    shut off completely if the inlet temperature exceeds 165 degrees. A sudden or excessive rise of water temperature indi­ cates a failure of the cooling circuit due to : (a ) improper valve settings, (b ) blower motor failure, or (c ) clogging of the radiator by leaves, paper, etc.

  • Page 47: F Irst Radio-Frequency Amplifier Stage

    when the thermostats are clos e d and curren� flows in the heater cir cuits . Each os cillator is adj us te d as a unit to the operating frequency and will maintain its calib ration well within ± 10 cycles .

  • Page 48: Second Radio-Frequency .Amplifier Stage

    across resistance R7A and is indicated by the "Test Meter11 switch DlOA in position 11Vl Plate X20 . "Plate current" measured in this equipment indicates the total current from the tube cathode, a portion of which may flow to other ele­ ments of the tube than the plate, such as the grid and screen.

  • Page 49: Third Radio-Frequency Amplifier Stage

    Third Radio-Frequency Amplifier Stage Res i stances R93 . 1A and R93 . 2A const itute the grid load of the third amplifier tub e V3A. The plate c ircuit contains the anti-s ing as s embly Ll9A and R83A operating int o the transformer L9A and into the coupling circu it through con­...

  • Page 50: Power-Supply C Ircu Its

    ground. Each tube s pace current is measured by the drop across meter shunts that are provide d in the c ir cu its . output circuit of V4A and V5A is conne cted to terminal 65, so that audio-frequency power is connected to the D-151135 modulating amplifier acros s terminals 65 and 61 in series with the radi o-frequency output ac ros s terminals 54 and 55.

  • Page 51: First Radio-Frequency Amplifi Er Tuning

    elements of the tubes after shipment or handl ing, thus mini­ W ith the " Oscillator ­ mizing the pos s ibility of flashovers . Amplifi er C ontrol 1 1 switch, DllF, o f the s pe cial D-99116 con­ tro l unit in the "...

  • Page 52: Second Radio-Frequency Amplifier Tuning

    the " Test Meter " switch on the " Vl Plate X20 " pos ition. "RF Output " c ontrol s et at ab out 80, adj us t the With the " Plate C ircuit Tuning Vl " control unti l the " Test Meter " in­ dicates a minimum, or until the "...

  • Page 53: Third Radio-Frequency Ampl Ifi Er Tuning

    the tuning by readjusting the " Plate C ircuit Tuning V2, 1 1 " Output c ir cuit Tuning V2 11 and " Plate C ir cu it Tuning 3rd max imum. .Amp. 1 1 controls until the " Test Meter " indicates a Then adjust the "...

  • Page 54: Amplifier

    ing is low it is an indication that the inductance of the circuit associated with that meter is too high and the num­ ber of active turns should be reduced. Final Adj ustment of the Second Amplifier After all circuits of the D-99110 oscillator amplifier are turned, the following final adj ustments should be made "RF Output "...

  • Page 55: Adjustment Of S Liders On R61A

    means of the " RF Output " control only. If any tendency toward paras itic oscillations exists after the above adjustments are completed, the neutral iz ing of the third radio-frequency ampl ifie r should b e che cke d. This should b e done without changing any of the other radio­...

  • Page 57: Audio Monitoring Rectifier

    the series circuit, composed of R44A and Cl3A, until th e undesired oscillation disappears. When the carrier is ad­ j usted for normal output modulate the tra.. �smitter with a single frequency of 400 cycles, and observe the wave for different values of modulation.

  • Page 58: Circuit Description

    single-frequency 100 per cent modulation is approximately -f- 10 db. The direct-current component of this rectifi er is used to operate relay SSA, which in turn closes the audio input circuit when the carrier output is normal. Re ducing the carrier to zero either manually or by the protective circuits that are provided removes all the feedback voltage.
  • Page 59 switch D30C, which for s afety is inter lo cked with the c ontrol ci rcuit, permits checking of neutral ization by connecting a cathode-ray tube at jack J2 C . C 6C and C31C are the output tuning condensers fo r the ampl ifier, while L30C couples the output to the g rid circuit of the D-991 18 power ampl ifi e r .

  • Page 60: Adjustment Of Input Circuit

    Units C, D and E should be completel y adjusted for 50-kw operation before adjustment s for 5-kw emergency operation are attempted , and accord­ ingly D6G ( control transfer switch ) sh ould be in the 50-kw position, D2H (50-kw Rect. Fil. Switch) closed, and D5G ( 5-kw Rect.

  • Page 61: Output Circuit Tuning

    When neutralization is completed a readjustment of con­ denser C31A 110utput Circuit Tuning 3rd Amp. 11 may be required because of the change in input capacity of the modulating amplifier. Output Circuit Tuning In adjusting the output circuit a preliminary tap is chosen on L30C to give an estimated inductance that will tune a capacity of 375 mmf.

  • Page 62: 9118 Power Amplifier Unit

    D-99 118 Power Amplifier Unit Units D and E, Schematic Figure 9 C ircu it Des cr ipti on This power amplifier empl oys two tubes , VlE and V2D, connected in a high-efficiency c ircuit, driven by the output of the D-151135 modulating ampl ifier and c orme cted to the antenna system by a coaxial transmi s s i on line .
  • Page 63 C oil LSD and resistance R6D provide a small V2D at jack JlD. part of the output of the amplifier at terminals 61 and 62 to be us_ed for stabilized feedback. Between the transmission-line coupling coil LlD and the line there is connected a radio-frequency harmonic filter con­ sisting of coil L2E and condensers C2.

  • Page 64: Circuit Adjustment

    Circuit Adjustment Antenna Couplin g Equipment The output of the 407A-4 Equipment is us ua ll y fe d t o one or more tower radiators through c oncentric transmis s ion l ines and suitable coupling circuit s .

  • Page 65: Tuning Of Output Circuit

    wavelength in a coaxial line of the type supplied is ab out 0. 98 of the nominal wavelength in space ; accordingly, if harmonic radiation is not unusually s evere , sufficient sup­ press ion may b e obtained by carefully measuring and cutting the s hunt l ine t o a length of 0 .

  • Page 66: Adjustment Of Load Impedances

    quency and give a high degree of suppress ion at this har­ monic . L2E is adjusted by measuring the input impedance of the harmonic fi lter at the carrier frequency when the fi lter is terminated in a non-inductive r e s is tance of 6 2 . 5 ohms . ma.king this measurement the filter is disconnected from the transmis s ion lines at one end and from LlD at the other .

  • Page 67: Tuning Of Grid C Ircuit

    B y means of a radio-frequ ency bri dge, arrange d to meas ­ ure parallel components of grounded impe dances, and with terminal 55 of unit E grounded, measure the paral lel res ist­ ance b etween the tube s ocket of V2D and ground at the carrier frequency.

  • Page 68: Final Tuning Of D-99118 Power Amplifier 6

    acros s the grid of VlE has a pos itive value e qual to the negative sus ceptance of the inter-grid coupl ing condens er Cl5E and its as sociate d trimmer capacity Cl3D . T o obtain this relation, choos e arb itrary taps on L3E and on the sampling coils L5D and L5E, and apply excitation to the final stage with plate voltage sti ll remove d from this stage by means of di sconnect switch D58P, and with...
  • Page 69 to the final stage . Place the entire transmitter in opera­ tion. After a warming-up period at minimum plate voltage, rais e the plate vo ltage to 16, 000 or 18, 000 volts and apply excitation until the " Plate Current Vl" meter reads about amperes .
  • Page 70 total plate current should b e b etween 4 . 55 and 4. 7 amperes . The plate current of V2D ma.y b e increas ed or decreased by changing the s etting of the " Inter-Grid Coupling " c ontrol . This requires a s light readjustment of the "...
  • Page 71 proper taps on coils LlOD and LllD to obtain a null indica­ tion on meter MlD " Protective C ircuit" when the power ampli­ fier is tuned. Open switch D3D . Choos e arb itrary taps on LlOD and LllD. L7D, having chos en a tap for the cathode ray in­...

  • Page 72: Modulating The Transmitter

    With the final stage adjusted to the pro per operating conditions at the unmodulate d carrier output, it is necess ary next to ob serve the operati on with modu lati on applie d. For ideal distortionles s operati on with no carrier shift the antenna current should rise 2 2 .
  • Page 73 emis sion of the tubes in the power ampl ifi er is suffic ient to furnish the increas ed peak power . T o faci litate the modulating adjustment, the operator should calculate in advance what his antenna current or transmiss i on-l ine current is to be at c omplete modulation, in acc ordance with the ris e he wishes to obtain with respect to the carr ier current .

  • Page 74: Adjustments For 5-Kw Emergency Output

    des i red value b y approximately the same amount . By the above process the proper filament voltage set­ tings are found for maximum tube life at the requir ed peak power output of the transmitter. This is a procedure which should b e repeate d monthly so that as the tubes age the fila­...
  • Page 75 the 50-kw clip 2 1 on Fig. 5 Start up the transmitter in the normal manner with the RF Output C ontrol in the minimum Inc reas e the s etting of this control until there pos ition. is an indicati on of plate current on meters MlC and M2C , and adj ust condens er C6C for a minimum indi cati on of MlC and M2C .

  • Page 76: Starting The Transmitter

    STARTING THE TRANSMITTER Preliminary To start the transmitter, all the manual circu it bre akers in the Power Distribution Unit except the emergency plate breaker CB 73P should be thrown to " ON " . Che ck the voltage of the three phas es of the power supply by means of the "...

  • Page 77: Water System

    high-voltage grounding switch open, all the gate lamps will light and the b ias contactor S 56P wi ll operate, energiz ing • the b ias rectifiers Unit K and lighting the "Mod .Am p. B ias " lamp E21F and "Power .Amp.

  • Page 78: Amplifier Filaments

    Close the switch " Ampl ifier Filaments " which en­ ergizes S 53P supplying power to the mo dulating ampl ifier filaments , and S 58P supplying power to the amplifier fila­ ments through the starting res istors R51-53P . After a delay of a few s econds S6 3P operates , energiz ing S 59P which shorts R51-53P and applies full voltage to the fi laments .

  • Page 79: 5-Kw Emergency Operation

    the overload lamps . 5-kw Emergency Operation The cut-back to 5-kw is effected as fol lows : Open "H. V . Rectifier " switch D4F . This o pens pl ate ( 1) c ircuit breaker CB6 5P, removing the 460 volt supply from Unit H, and taking the transmitter off the air .
  • Page 80 50-kw 5-kw Function S 3E Left S3E Right T o trans fer transmis s ion line between 50- and 5-kw outputs and to ground un­ us ed c ircu its . To trans fer output of unit C b etween input to units D and E, and input to harmonic suppress ion network of unit C, and to ground unused circu it .

  • Page 81: Switch Functions

    o pening switch D21H and the 460-volt supply to the ampl ifi er units by opening circuit b reake r CB64P in the Dis tribution Cab inet . During 5-kw operation the re are no voltages within the accessible enc losure exceeding the line vo ltage volts 3-phas e a-c , accidental contact with which is pre­...

  • Page 82: Modulating-Amplifier

    DlOA - 11Test Meter11 - Connects the test meter M2A to the various cir cuits in this unit. Dl3A - Link switch for adding capacity to neutralizing Dl5A ) - Link switches to connect thermocouple TC2A in condenser Cl5A. Leave open. Dl6A ) circuit.

  • Page 83: Control Unit

    only if the rectifier switch DlH has been oper­ ated to ground the high vo ltage. D3D - Disab ling switch for protective circuit. Leave open unless troub le is experienced v1ith this circuit. Control Unit DlF - "Rectifier-Filaments" - Operates contactor to energize bias and high-voltage rectifier fila­...

  • Page 84: Power Amplifier

    trol of the plate regulator from fully automatic to manual control by means of push buttons K6F and K7E. Leave in 1'Automatic 11 pos iti on. DlOF - 110s c . Amp. Filaments tt - This switch operates a contactor to supply power to the os cillator­ Throw to "...

  • Page 85: Power Equipment

    K3F - " p Reset " - A momentary-contact pus h button which may b e operated to reset the overload lamps after any overl oad indication has been obtained. Power Equipment All manual circuit breakers in the distributi on cab inet, except CB 73P, should b e kept in the 110N11 pos iti on.
  • Page 86 ElF - Green lamp above DlF " Rectifier F ilament " . E3F - Green lamp above D2F uwater Systemn . E54F - Green Lamp above DlOF 110s c . -.Amp. Filaments " . These lamps l ight as s oon as power is supplied to the c ontrol circuit .
  • Page 87 operated or KlF has been operated to ener giz e S4F . • .Amp . Gate " lights after ElOF lights pro­ EllF - 110s c vided DllF is in the 110perate " position and all doors on the o s c illator ampl ifi er unit are clos ed.

  • Page 88: Overload Lamps

    E22F - " Power .Amp. B ias " lights after El6F provided c ontactor S56P operates to energiz e the power amplifier b ias rectifiers . E23F - Green lamp above D4F " H.V. Rectifier " lights after E9F " .Amp . Fil . " , E21F "...
  • Page 89 T4F . The failure of TlF, T2F, or T4F or the opening of "A-C C ontrol Circuit Power" or "D-C C ontrol Circuit Power" wi ll extinguish all of the overl oad lamps . These lamps are l ighted only by the operation of K3F . Once lighted they are extinguished only by the o peration of s ome overload circuit .

  • Page 90: Supplement.ary Notes

    General Electric Maz da No. 46 Lamps are us ed to il­ luminate the meters . Vacuum Tubes The types of vacuum tub es us ed in the 407A-4 Equipment and their corresponding desi gnati ons are given Table 9 .

  • Page 91: Water-Cooled Tubes

    hours should b e run with filament vo ltage only for 30 minutes before applying plate voltage. New tub es s hould be operated ap­ with filament voltage only for at least 2 hours b efore pl ication of plate voltage . If at the end of this t ime it appears that any mercury is still condensed on the anode or upper part of the tube, particu larly on the glass near the...

  • Page 92: Wd2W

    Transmitter . " During regular operati on, a 298A vacuum tube can b e changed with a minimum o f servic e interruption b y cutt ing back to operation, and opening CB 64P to deenergize the 5-kw fi laments of the 298A tubes . The coo ling-water supply to the se tub es may be shut off eithe r by operating valves ZlD, Z 2D, Z lE, Z 2E, if units D and E are supplie d with these...

  • Page 93: Installation

    the indic�tor reading and water flow increase, contact closes b efore contact E c l os e s . the indi cation de• creases , c ontact E opens b e fore c ontact P opens . These c ontacts are of t he b rush and commutator type , and in this e quipment the ir functi on is to control relay S2W.

  • Page 94: Shipping Stop 8

    Screw vapor traps into valve manifold, in place of plugs . Attach valve manifol d and traps to pipe nipple and tube by means of unions , b ending tube as required to fit in plac e . Connect the left-hand end o f the three-valve manifold to the upstream or entrance of the venturi .

  • Page 95: Filling Chambers And Piping With Water

    to the cover plate of the low-pressure chamber and extending down into the mercury. The volume of this "stick" is s o distributed that the dis placement o f mercury at any point wil l be such as to produce the proper reading on the chart . THEREFORE, FOR ANY GIVEN POSITION OF THE INDICATOR ARM THERE IS ONE POS ITION ONLY OF THE MERCURY IN THE TWO LEGS OF THE 11 U 11 TUBE TO GIVE THE CORRECT READING FOR THE CORRE­...

  • Page 96: Zero Adjus Tment

    Crack R . H. valve and bleed air from top of R. H . vapor C lose R. H. bleeder and R. H. valve . trap . Zero Adjus tment Close all three valves on instrument manifold, c irculate water through the venturi . O pen center valve very s lightly.

  • Page 97: Nitrogen Gas System

    Any additional supply of lub ricant may be purchased from the Foxboro C ompany. In the 407A-4 Radio Transmitting Equipment, dry oil­ pumpe d nitrogen gas under press ure is us ed in the concentric transmis s i on line and harmonic shunt and als o in the ad­...

  • Page 98: Operation

    pheric pressure. In addition to the enhanced factor of s afety obtained, the gas pressure in the concentric trans ­ mission line prevents the entrance of moisture and gives an indication of faults which may develop in the soldered or The escaping gas at such a fault excludes gasketed joints.
  • Page 99 WHI IE MECHANICAL WORK IS BEING DONE ON LINES OR CONDENSERS , THE GAS PRESSURE SHOUID BE RE­ MOVED THEREFROM. To fil l the transmis s i on l ine, harmonic s hunt or con­ dens ers proceed as fol lows : Connect a 200 cubic fo ot cyl in­...
  • Page 100 To fill the 2-5/8 inche transmis s ion line, open Z4N on CMlN, fill ing the line to 45 pounds pressure as indicated by M4N. C lose Z4N and observe whether the pressure in the line remains stab le or whether the pre ssure gradually decreases , indicating a leak.
  • Page 101 cated by a gradual reduction in gauge readings . I f a more serious fault should develop in the transmis s ion line or in the condens ers, the leak must b e dis covered and repaired at the next shutdown period. In the meantime a frequent check of the gauge readings mus t be made and the pres sures restored to normal as required.

  • Page 102: Power Contactors - Des Cription And S Ervicing

    does not support life ; if it should wholly fill a room, a person in that room would suffocate from lack of oxygen. For this r eason the bleeder and bl owoff valves are vented to the exterior and proper precautions should be taken in dis ­ charging cylinders or performing any other oper ations in­...

  • Page 103: Maintenance

    of extreme beading is it neces sary to treat them. Dress ing should b e done with a fine fi le, not with emery c loth, as abrasive granules imbedded in the contact sur faces may rai se the contact resistance and produc e a tendency of the con­ tacts to weld.

  • Page 104: Motor-Operated C Ircuit Breaker - Maintenance

    MAINTENANCE OF MOTOR-OPERATED PLATE CI RCUIT BREAKER C ircu it breakers, as distinguished from other type s of cir cuit-interrupting devices such as contactors and relays, are primarily designe d for infrequent interruptions of ex­ tremely he avy overloads . The maintenance required on a cir­...

  • Page 105: No . 1 - Unit A - Typical Meter Readings

    should be replaced with a new breaker or r eturned to the man­ ufacturer for complete s ervicing if any failure of the breaker devel ops during these tests . Detailed information for the ins tallation, operation, and ins pecti on of this circuit breaker is supplied at the time of instal lation, and should be retained for future ref- erence o TABLE...

  • Page 106: No. 2 - Unit A - Plate, Screen And Fil Ament Voltages

    TABLE 2 D-99110 OSC ILLATOR-AMPLIFIER PLATE , SCREEN, FILAMENT VOLTAGES Des i g . No . Plate Screen F i lament 450 to 500 180 to 200 12. 4 to 12 . 8 VlA , V2A , V7A & V8A 200 to 250 170 t o 190 9 .

  • Page 107: No. 4 - Unit A - Res Is Tance Adjustments

    T AB L E 4 D - 9 9 1 1 0 O S C I L L A T OR- A MP L I F I E R R E S I S T A N C E A D JUS TMEN T S R e s i s t a n c e Ap p r ox .

  • Page 108: No. 6 - Units D And E - Typi Cal Meter Readings

    TABLE 6 D-99118 POWER AMPLI FIER TYPICAL METER READINGS D e s i g . No . Title Reading Protect ive C i rcuit 0 to 2 ma . Total Plat e Current 4 . 55 to 4 . 7 amps . ( no mod .

  • Page 109: No . 8 - Fuses

    TABLE NO . 8 l< ' USES Des i g . N o . Ca t . N o . Current Rat ing 5 Amp s . 250 Volts D&W Cat . tfl456 F l . lA F 1 . 2A 5 Amp s .

  • Page 110: No. 10 - Relay S Ettings

    T A B L E R E L A Y S E T T I N G S T i m e D e l a y R e l a y D e l a y M a k e m i n .
  • Page 112 ' L �� " COOLING UNIT MOTORS PUMP MOTO R S 1 - - - - - 1 S 2 W W D 2 W W I W WDIW D 4 P D I P _ _ _ 1 2F - - - D 2 P "' �...

  • Page 113: F I G . 1

    '° "- I '1 � � -S C 1 6 5 � CB 7 4P T58P " " " ;<; "' "' "' "' PR52P --67C R5 7 P D58P R56P L52P 4 5F S 61P L CSIP R55P _l41H 68F- F C 50P F i g .

  • Page 114: F I G . 1

    "' "- � � 1 6 3 1 6 5 � C 8 74 P T58P ;;:; PR52P --67C R5 7 P D58P R56P L52P S 61P l C51P R55P _l41H 6 BF - - - o -- 3 - � FC50P F i g .
  • Page 115 37-F 42-DPSIP T53P T55P T 5 4 P 32 3 3 D 20 H NEG. TERM. - - F C 5 0P - - PR 5 2 P - - 9 - F C 50P G I H R I H R 3 H R 4 H R 5H...
  • Page 116 3 1 K- -' - - - 1 5 9 -f T 7 K PRI K -- - 1 6 1 -f T 5 K 4DK- -- 39K - - - F i g u re 3 - U n i t K - D-99 120 B i as Re c t i f i e r T u b e U n i t - Sc h emat i c...

  • Page 117: Fig

    � ' - +-- - _J__ - - t - , , . . : . : : =1===4�---1--< H 23-H - -Q77 Q BO 860- - - 14 - G - - - __J - - - - - - 10-S3E - - -- �...
  • Page 118 "' "' "' " ., 1 "' I ol "' "' t- 1 <e l "' "' "' � I "' "' ".' "' ' "' " "' "' "' 3 3 - c - � M 8 F 1 1 9 3 2 - C - - 3 4 - c - �...
  • Page 119 " I<!) I <{ "- "- <O "] <ll I I I "' "' "'"' - "' " "' "' "' "' t- 1 .,, 1 "' .., 1 "' I <O <O <O <O <O "' "' ' " ' ;;...

  • Page 121: System S Chematic

    (as••) ··" _ _ _ _ _ _ _ _ 8. BIAS D-99114 H. V RECTIFIER UNIT (MODIFIE D) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ D-99120 BIAS RECTIFI E R U N I T 0 - 9 9 1 1 9 HIGH VOLTAGE RECTIFIER UNIT - - 1...
  • Page 122 0 - 99 1 1 8 H I GH E F F I C: I E NC.Y POW E R At.<P L I F I E R r- - - ·- - L34C TUBE UN IT TUBE UNIT NO. 2 ••...

  • Page 125: Power System

    D20H D I P i§ C B 74 P "' T58P "' "' "' PR5 2 P D58P R 5 7 P L52P - -<r=--- -0 60E- 4 5F " " [ " " R55P - - 4 1 H T5 6 P 6 BF - - P L ATE REGULATOR...
  • Page 126 L E G E N D ® VACUUM TUBE SOCKET -- - WAT E R P U M P REMOTE INDICATING FLOW METER --- REMOTE I NDICATING THERMOMETER REMOTE INDICATING MILLIAMMETER Z 9 W --- DUPLEX WATE R PRESSURE GAUGE @----- M 8F WAT ER PRESSURE GAUGE...
  • Page 127 FREQ. MON. - - - - - - - • o - - ., 702A OSCILLATOR OIJA Ll9A Cl9A N0,2 . or R20A � � I a: IL'. - - - - � � � < � �� R 6 A �...

  • Page 128: Fig

    1 2 1 - F - - 1 0-- 0 PSOP 53- F 57-A PR 2C 1 20 F- - M 5 C R35.IC C 3 8 C R 2C R I C 0 6 C TC I C M 4 C R 3 2 C C 3 7C -- - - - - - - - - - - - - - -...
  • Page 129 C l 3D L 12 D C'7.ID L 3 D - - 56-A l 8D c::: :: :J PRID CI D R2.2D R. F. GN D .-o- - - - - - -+ - e- -+ - - - -+- - - - - - --< 1-- - -+- - - - -+ - - - - - - - - - - - - - ..- - - +- -+- - -+- - - - - -e - - - - - - 1 -- - 1 4 - 0 - -1 LIOD L l l D...

  • Page 130: Fig

    L 4 D C l 3 D L 9 E L 12 D C15E C7.ID C71E C72D C 72E L I E , - -, - -56-A c=J PRI E L3 E C I E R2. 2 D Ll l D LIOD J I D R 4 D...
  • Page 131 ROTAX FLOW CONTRO L L E R FUNNEL FILLER SHAPED PLUG GASKET IN R E C E S S M E RCURY B A F F L E S HA F T A N D B E A R I N G P R E S S U R E T I G H T H I G H P R E S S U R E CHAMBER S T I C K...
  • Page 133 r--... rL - -"i r - -'i � LINE BP C == == == == == == =:J- 5" C IZ C I E 2 � LINE - - --cl_ r<L , - - - - TO OUTSI D E O F BUILDING NITROGEN CONTR NIFOLDS...
  • Page 135 D I S T R I B U T O R IN T ll E U N I T E D S T AT E S Jacksonville Omaha San A n tonio Akron Dallas Davenport Kansas City Orlando San Diego Albany Knoxville Peoria...

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