*
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 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...
