Aircraft Radio Corporation SCR-274-N Operating Instructions Manual Download Page 5

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In  case  it  should  become  necessary  to  prevent  the  capture  of  this  equipment  and  when  ordered  to  do  so,  DE­

STROY  IT  SO  THAT  NO  PART  OF  IT  CAN  BE  SALVAGED,  RECOGNIZED  OR  USED  BY  THE 

ENEMY.  BURN  ALL  PAPERS  AND  BOOKS. 

Means:-

1.  Explosives,  when  provided. 

2.  Hammers, axes, sledges,  machetes,  or  whatever  heavy  object  is  readily  available. 

3.  Burning  by  means  of  incendiaries  such  as  gasoline,  oil,  paper,  or  wood. 

4.  Grenades  and  shots  from  available  arms. 

5.  Burying  all  debris  or  disposing  of  it  in  streams  or  other  bodies  of  water,  where  possible  and 

when  time  permits. 

Procedure:-

1.  Obliterate  all  identifying  marks.  Destroy  nameplates  and  circuit  labels. 

2.  Demolish  all  panels,  castings,  switch- and  instrument- boards. 

3.  Destroy  all  controls,  switches,  relays,  connections,  and  meter.s. 

4.  Rip  out  all  wiring  and  cut  interconnections  of  electrical  equipment.  Smash  gas,  oil  and  water-

cooling  systems  in  gas-engine  generators,  etc. 

5.  Smash  every  electrical  or  mechanical  part,  whether  rotating,  moving,  or fixed. 
6.  Break  up  all  operating  instruments  such  as keys,  phones, microphones, etc. 
7.  Destroy  all  classes  of  carrying cases, straps,  containers,  etc. 

8. 

Bury  or  scatter  all  debris. 

DESTROY  EVERYTHING! 

For 

U. S. 

Army  Air Flirce Personnel: 

In  the  event  of  malfunctioning,  unsatisfactory  desig n,  or  unsatisfactory  installation  of  any  of  the  compon­

ent  units  of  this  equipment,  or  if  the  material  contained  in  this  book  is  considered  inadequate  or  erroneous, 
an  Unsatisfactory  Report,  AAF  Form  No.  54,  or  a  report  in  similar  form,  shall  be  submitted  in  accordance 

with  the  provisions  of  Army  Air  Force  Regulation  No.  15-54  listing: 

1.  Station  and  organization. 
2.  Nameplate  data  (type  number  or  complete  nomenclature  if  nameplate  is  not  attached  to 

the  equipment). 

3. 

Date  and  nature  of  failure. 

4.  Radio  model  and  serial  number. 

5.  Remedy  used  or  proposed  to  prevent  recurrence. 

6.  Handbook  errors  or  inadequacies,  if  applicable. 

For 

U.  S. 

Navy Personnel: 

Report  of  failure  of  any  part  of  this  equipment  during  its  guar�nteed  life  shall  be  made  on  Form  N.  Aer. 

4112,  "Report  of  Unsatisfactory  or  Defective  Material,"  or  a  report  in  similar  form,  and  forwarded  in  ac­
cordance  with  the  latest  instructions  of  the  Bureau  of  Aeronautics.  In  addition  to  other  distribution  required, 

one  copy  shall  be  furnished  to  the  inspector  of  Naval  Materiel  (location  to  be  specified)  and  the  Bureau  of 

Ships.  Such  reports  of  failure  shall  include: 

1.  Reporting  activity. 

2. 

Nameplate  data. 

3.  Date  placed  in  service. 
4.  Part  which  failed. 

5.  Nature  and  cause  of  failure. 

6.  Replacement  needed  (yes-no). 

7.  Remedy  used 

or 

proposed  to  prevent  recurrence. 

For  British  Personnel: 

Form  1022  procedure  shall  be  used  when  reporting  failure  of  radio  equipment. 

RESTRICTED 

iii 

Summary of Contents for SCR-274-N

Page 1: ...AN 08 40SCR274 2 HANDBOOK OF OPERATING INSTRUCTIONS for RADIO SET SCR 274 N RESTRICTED For Official Use Only COPlfYERUTHOGRAPHCORP ClEVELAND OHlO APRIL l945 3 OOO Approved 4 OCTOBER 1944...

Page 2: ...unicated either directly or indirectly to the press or to any person not holding an official position in His Majesty s Service The information contained in restricted documents and the essen tial char...

Page 3: ...t View Left Radio Control Box BC 473 A for one Receiver Front View Right 1 6 Rack FT 220 A and Mounting FT 221 A for Receivers Front View 1 7 Radio Control Box BC 451 A for Transmitters Front View 1 8...

Page 4: ......

Page 5: ...he event of malfunctioning unsatisfactory desig n or unsatisfactory installation of any of the compon ent units of this equipment or if the material contained in this book is considered inadequate or...

Page 6: ...Section I RESTRICTED AN 08 40SCR274 2 figure Radio Set SCR 274 N Components iv RESTRICTED...

Page 7: ...ED The following table lists the equipment supplied a RECEIVING EQUIPMENT See figures 1 1 to 1 11 Transmitter Frequency in megacycles Radio Transmitter BC 696 A 3 0 4 0 Radio Transmitter BC 457 A 4 0...

Page 8: ...F1 220 A 4 0 FT 221 A 16U6 x 102 x 1 1 0 PL 152 A 0 13 Pl 147 A PL 15I A BC 450 A 9Y2 x 51 2 x 21 2 7 MC 212 MC 213 MC 214 FT 222 A 9Y2 x 51 2 x Y2 0 7 JAN 12SK7 JAN 12SK7 JAN 12KBY JAN 12KBY JAN 12SR...

Page 9: ...smitter installations Quantity per Name of Unit I Army Type Navy Type Equipment Designation Designation 1 Radio Control Box BC 451 A 1 Mounting FT 228 A 1 Plug PL 153 A 1 Modulator Unit BC 456 A BC 45...

Page 10: ...nation Overall Dimensions inches 7 x 111 i X 12 2 Weight pounds 1 7 4 FOR TWO TRANSMITTER INSTALLATION Includes two transmitters two plugs and two tube sets as in paragraph 2b 2 of this section plus Q...

Page 11: ...RESTRICTED Section I AN 08 40SCR274 2 Figure J 2 Typical Radio Receiver with Adapter for Local Control Figure J 3 Typical Radio Transmitter Front Panel RESTRICTED 1 5...

Page 12: ...08 40SCR274 2 figure 1 4 Radio Control Box BC 450 A for Three Receivers front View figure 1 5 Radio Control Box BC 496 A for Two Receivers front View Left Radio Control Box BC 473 A for one Receiver...

Page 13: ...ion I AN 08 40SCR274 2 Figure 1 6 Rack FT 220 A and Mounting FT 221 A for Receivers Front View Figure J 7 Radio Control Sox SC 4SJ A Figure 1 8 Antenna Relay Unit SC 442 A for Transmitters Front View...

Page 14: ...R274 2 Figure J 9 Rack FT 226 A and Mounting FT 227 A for Two Transmitfers Left Rack FT 234 A and Mounting FT 232 A for One Transmitter Right J 62 P Sl Figure J J O Rack FT 33 J A and Mounting FT 332...

Page 15: ...m n m 0 0 Figure J J J Modulator Unit 8C 456 8 Top View with Shield Removed Also 80ttom View of Dynamotor DM 33 A l Z o com I O nn to m 0 I to II o I...

Page 16: ...wire may be used for the lead between the receivers and the antenna relay c Support the leads on ceramic stand off insu lators When protection against accidental contact with the aircraft structure is...

Page 17: ...rnished and will provide satisfactory operation for most antennas If proper tuning of the transmitter is not possible dlle to large antenna capaci tance or inductance series capacity may be added in s...

Page 18: ...ting the LOCK knobs one half turn clockwise to a stop in which position the engraving LOCK on the knob will read right side up 15 Release the built in telephone key by rotating it in a counterclockwis...

Page 19: ...or for control in one location of part of the receivers and in another location of the remaining receivers When re mote control boxes are used each receiver so controlled must be equipped with an Adap...

Page 20: ...EMERGENCY OPERATION AND REPAIR I FUSE REPLACEMENT a FUSE IN RECEIVER RACK WARNING Dynamotor DM 32 A on each of the receiv ers generates 250 volts direct current The danger of exposure to the voltage m...

Page 21: ...RESTRICTED Section V AN 08 40SCR274 2 SECTION Y SUPPLEMENTARY DATA RESTRICTED 5 1...

Page 22: ...F AMP CATHODE CURRENT AND FIRST I F AMP TUBES VT 131 11 15 MI L LI AMPERES P ARTS L1ST FOR TEST SET RC 54 A FOR TESTING COMPONENTS OF RECEIVING EOUIPMENT QUAN DESCRIPTION W E DWG NO I I I I I I I I 3...

Page 23: ...MODULATOR UNIT AND RADIO TRANSMITTER ENERGIZED THERE WILL BE APPROXIMATELY ONE VOL T DROP IN THE LEADS QUAN DESCRIPTION 2 i tc0RDS CD 524 MOOULATOR UNIT BC 456 A BOR E TO lEST UNI 1 85 A AND TEST UNIT...

Page 24: ...IEW I WIRING COLOR CODE a PL END hEW OF PLUG PL J58 CONSISTS OF PLUG PL 119 ALL IT E MS IN THIS BL OCK DISCONTINUED ON LATER MODEL SO MARKED 754 5 TOGETHER WITH FERRULE ASSEMBLY 7639 r 1i i f j BLACK...

Page 25: ...234 A 0 t j NOTE I RESTRICTED Section V AN 08 40SCR274 2 TEST UNIT 1 85 A TO RACK FT 234 A AN TENNA RELAY I T l BC 442 A I I 1 ANTENNA POST I ON RADIO L TRANS TER TO GROUND BINDING POST ON RACK FT 23...

Page 26: ...VER WEIGHT OF UNITS TO BE COMPONENT INSTALLED PARTS 5 7 LBS 0 3 3 0 0 1 O I 0 7 I 1 3 2 0 8 2 2 3 1 0 3 4 0 0 2 0 13 0 17 0 12 i 616 1 3 1 5iS 616 7 I 1 104 1 TVPIGAL REAR VIEW OF RADIO RECEIVERS RACK...

Page 27: ...CK AND MOUrmNG TWO TRANSMITTERS RAOK FT 2 26 A AND MO TING FT 227 A SHOWN TYPICAL SIDE VIEW OF TRANSMITTER RACK AND MOUNTING figure 5 6 Radio Set SCR 274 N lnstallation Dimensions and Weights Of Trans...

Page 28: ...FT 240 A 1 7 RADIO CONTROL BOX BC 451 A AND MOUNTING FT 228 A 0 9 ANTENNA AELAY UNIT BC 442 A AND MOUNTING FT 229 A 2 2 ANTENNA RELAY UNIT BC 4 42 AM AND MOUNTING FT 229 A 2 0 MODULATOR UNIT BC 456 A...

Page 29: ...SHALL BE NO CROSS OVERS IN THE WIRES BETWEEN THE BACK PLATE AND INSULATOR ASSEMBLY E ASSEMBLE INSULATOR INTO SHELL AND REPLACE SCREW F REFERENCE MAY BE MADE TO AIR CORPS SPECIFICATIONS AND OTHER AIR C...

Page 30: ...05 INSIDE DIA MET ER OF C ASING 242 000 PARALL EL WITH FLATS ON SHAFT CR IMPING DETAIL CASING REMOVED NOTES I CUT SHAFTING TO REQUIRED LENG T H L 2 WITH CASI NG STRETCHED OUT T O MAX LENGTH CU T CASIN...

Page 31: ...SHAFT MC 215 TUNING SHAFT Me 215 TUNING SHAFT MC 215 RADIO RECEIVER BC 455 A OR BC 455 B 6 0 9 1 MC RACK FT 220 t O PRIMARY WHITE I SOURCE t 24 28V D C BLACK r RADIO RECEIVER DYNAMOTOR BC 453 A OR PL...

Page 32: ...TIIANSMlssiOH S OAAlI 5 oJ 0 A PS O 4 ESr 9 oA EST 9 S AMP s 533 28V POWER SUPPi Y 534 2 V INTERPHONE HEAoSEr CONNEcnoNS CON ECT 53 A W I RE S 3I A TO R I OR COMMAND SET POSITIOIY 53Z 8 IN INrGRPI OH...

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