SCR-AS-183_serv_user_TO08-10-158_1943.pdf

INSTRUCTION BOOK FOR ARMY AIR FORCES TECHNICAL ORDER No. 08.10.158 OPERATION AND MAINTENANCE OF RADIO SET SCR-AS-183 RESTRICTED NOTICE :-This document contains information af fecting the national defense of the United States within the meaning of the Espionage Act, 50 U. S. C., 31 and 32, as amended. Its transmission or the revelation of its contents in any manner to an unauthorized person is prohibited by law. (AR 380.5) The information contained in restricted documents and the essential characteristics of restricted materiel will not be communicated to the public or to the press, but may be given to any person known to be in the service of the United States and to persons of un doubted loyalty and discretion who are cooperating in Government work. PUBLISHED BY AUTHORITY OF THE CHIEF SIGNAL OFFICER APRIL 3, 1943 REPORT OF MAJOR FAILURE IN THE EVENT OF MAJOR FAILURE OF ANY OF THE COMPONENT UNITS OF THIS EQUIP. MENT, A REPORT SHALL BE SUBMITTED IN THE FORM INDICATED BELOW. COPIES OF THIS REPORT SHALL BE FOR WARDED TO THE CHIEF, SIGNAL SECTION, AIR SERVICE COMMAND, PA TTERSON FIELD, ,FAIRFIELD, OHIO, AND TO THE DIRECTOR, SIGNAL CORPS AIRCRAFT SIGNAL SERVICE, WRIGHT FIELD, OHIO. 1. Contract or order number. 2. Organization and station. 3. Nomenclature of equipment. 4. Nomenclature o,f component unit. 5. Date and nature of failure. 6. Type of airplane in which installed. 7. Recommendations. iii Paragraph 1. GENERAL TABLE OF CONTENTS SECTION I-DESCRIPTION Page 1 2. COMPONENT PARTS . . . . . . . . 1 3. ADDITIONAL EQUIPMENT REQUmED . 2 4. POWER CONSUMPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 5. DESCRIPTION OF PRINCIPAL COMPONENTS . 3 a. Radio Receiver BCAS229 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 b. Radio Control Box BCAS231 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 c. Radio Transmitter BCAS230 . 5 d. Radio Control Box BCAT232 . . . . . . . . . . . . . . . . . . . . . . . . 5 e. Coil Set C436 and Coil Set C437 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 f. Coil Sets C.431, C432, C433, C434 and C435 . 6 g. Dynamotor Unit BDAS83 . 6 h. Antenna Switching Relay BCAS198 . 7 i. Chart MC401 . 7 j. Dial MC-372 and Dial MC390 . 7 k. Vacuum Tuhes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 SECTION II-EMPLOYMENT 6. INSTALLATION . 11 a. Bonding and Shielding of Plane Components . 11 b. Antenna Requirements . 11 1. Operation on Separate Antenna for Radio Receiver BC-AS229 . 11 2. Operation on Separate Antenna for Radio Transmitter BCAS230 . 11 3. Operation on Single Antenna . 12 c. Installation of Components . ,. 13 1. Radio Receiver BCAS-229 and Radio Transmitter BCAS-230 . 13 2. Radi.o Control Box BCAS231 and Radio Control Box BCAT232 . 13 3. Dynamotor Unit BD-AS-83 . 14 4. Junction Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 5. Tuning Unit MC-125, Control Unit MC-135 and Tuning Shaft MC124 ,and Control Shaft MC134 . 14 6. C.ords. 15 7. Prep,aration for Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 7. OPERATION . 19 a. General . 19 b. Operating Test f.or Radio Receiver BC-AS-229 . 20 c. Operating Test for Radio Transmitter BCAS230 . 20 8. MICROPHONE TECHNIQUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 9. CHOICE OF FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 10. CHOICE OF TYPE OF TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 11. OPERATING ROUTINE 22 v TABLE OF CONTENTS-Continued SECTION III-FUNCTIONING OF PARTS Paragraph Page 12. RADIO RECEIVER BCAS229 AND RECEIVER COIL SETS . 0 0 0 23 13. RADIO TRANSMITTER BCAS230 AND TRANSMITTER COIL SETS . 0 00 0 26 14. RADIO CONTROL Box BCAS231 . 0 0 29 15. ANTENNA SWITCHING RELAY BCAS198 . 0 0 0 0 0 29 16. DYNAMOTOR UNIT BDAS83 . 0 o. o 00 29 17. COIL SET C436 AND COIL SET C.437 . 0 000 0 0 . 000. 0 0 0 0 31 18. RADIO CONTROL Box BCAT232 . ; . 0 0 0 31 19,. COOPERATION OF UNITS . 0 0 0 0 : 31 SECTION IV-MAINTENANCE 20. PRE-FLIGHT INSPECTION 35 21. SERVICE INSPECTION . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 35 22. REPLACEMENT OF TUBE VT25A IN RADIO TRANSMITTER BCAS230 . . . 0 0 0 36 23. TROUBLE LOCATION AND REMEDY (MAINTENANCE CHART) . 0 37 24. USE OF TEST SET I-56-A FOR MAINTENANCE OF RADIO SET SCRAS-183 . 0 0 41 a. Transmitter Tube Currents . 0 41 b. Junction Box Voltages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 c. Tr,ansmitter Plate ,and Bias Voltages . 42 d. Re,ceiver Plate, Screen and Bias Voltages . 42 e. Vacuum Tube Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 f. Continuity Tests . 0 43 25. USE OF VOLTAGE AND CURRENT TABLES . 0 o. 43 SECTION V-SUPPLEMENTARY DATA 26. TABLE OF REPLACEABLE PARTS . 45 27. LIST OF MANUFACTURERS . 63 vi LIST OF ILLUSTRATIONS Figure 1. RADIO SET SCR.AS.183, PRINCIPAL COMPONENTS Page x 2. J UNCTION Box TMAH172 . . . . . . 2 3. RADIO RECEIVER BCAS229 WITH COIL SET C437 IN PLACE . ,. . . . . . . . . . . . . 3 4. RADIO TRANSMITTER BCAS230 WITH COIL SET C435 IN PLACE . 4 5. RADIO CONTROL Box BCAT232 (TRANSMITTING) . 5 6. COIL SET C437 (RECEIVING) . 6 7. RADIO CONTROL Box BCAS231 (RECEMNG) . 7 8. DYNAMOTOR UNIT BDAS83, BOTTOM VIEW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 9. ANTENNA SWITCHING RELAY BCAS198 . . . . . . . . . . 12 10. COIL UNIT C439 (DUAL, RECEIVING) . 13 11. CHART MC401 AND DIAL MC372 . 14 12. RADIO RECEIVER BC.AS.229, BOTTOM VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 13. RADIO TRANSMITTER BCAS230, BOTTOM VIEW . 17 14. RADIO RECEIVER BCAS.229, SIDE VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 15. RADIO TRANSMITTER BC.AS.230, SIDE VIEW . . . . . . . . . . . . . . . . . . . . . . . . 25 16. COIL SET C435 (TRANSMITTING) . 26 17. RADIO RECEIVER BCAS229, FUNCTIONAL DIAGRAM . ;. 28 18. RADIO TRANSMITTER BC.AS.230, FUNCTIONAL DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 19. RADIO SET SCR.AS.183, SCHEMATIC CIRCUIT DIAGRAM . 65 20. RADIO SET SCR.AS183, CORDING DIAGRAM . . . . . . . . . . . . . . . . . 67 21. COMPONENTS OF RADIO SET SCR.AS-183, PRACTICAL WIRING DIAGRAM . 69 vii SAFETY NOTICE OPERA TING OF THIS EQUIPMENT INVOL YES THE USE OF HIGH VOLTAGES WHICH ARE DANGEROUS TO LIFE. OPERATING PERSON NEL MUST AT ALL TIMES OBSERVE ALL SAFETY PRECAUTIONS. DO NOT DISCONNECT ANY CABLES OR OPEN ANY UNITS UNLESS ALL SWITCHES ARE IN THE OFF POSITION. THE PROPER SEQUENCE FOR SETTING THE EQUIPMENT IN OPERATION IS OUTLINED HERE IN. DO NOT A TTEMPT TO OPERA TE THE EQUIPMENT WITHOUT FIRST HA VING READ. THIS MANUAL COMPLEiEL Y AND EVEN THEN ONLY WHEN THE INSTRUCTIONS ARE FOL LOWED EXACTLY. ix FIGURE I-RADIO SET SCR-AS-I83, PRINCIPAL COMPONENTS x INSTRUCTION BOOK FOR OPERATION AND MAINTENANCE OF RADIO SET SCR.AS.183 SECTION I DESCRIPTION I. GENERAL Radio Set SCR-AS- 1 83 is intended for installa tion and operation in aircraft having 1 2-1 4. 25 volt d-c power supply systems. Radio Set SCR AS- 1 83 is primarily used for single-seated planes and provides communication from ship to ship or . from ground to plane over limited distances, ap proximately 1 5 or 20 miles for modulated trans mission. Radio Set SCR-AS- 1 83 is used to re ceive modulated or damped-wave signals at any frequency range mentioned below. Component Parts Antenna Swiching Relay BC-AS- 1 98 (includes Mounting FT-118) . . Chart MC-40 1 (for cockpit) . . Coil Set C-431 (transmitting 2,500-3,200 kc) . Coil Set C-432 (transmitting 3,200-4,000 kc) . Coil Set C-433 (transmitting 4,000-5,000 kc) . Coil Set C-434 (transmitting 5,000-6,200 kc) . Coil Set C-435 (transmitting 6,200-7,700 kc) . Coil Set C-436 (receiving 2,500-4,700 kc) . Coil Set C-43 7 (receiving 4.1 50-7,850 kc) . Coil Unit C-439 (Dual, Rec. 20 1 -398 kc and 2,500-4,700 kc) . . Coil Unit C-440 (Dual, Rec. 20 1 -398 kc and 4,150-7,700 kc) . . Dial MC-372 (0-100 div. , 201-398 and 2,500- 4,700 kc clockwise) . . Dial MC-390 (0-100 div. , 20 1 -398 and 4, 150- 7,700 kc clockwise) . . The frequency ranges of Radio Receiver BC-AS- 229 are 201 to 398 kilocycles and 2,500 to 7,850 kilocycles. The frequency range of Radio Trans mitter BC-AS-230 is 2,500 to 7,700 kilocycles. At any frequency within this range it is used to transmit unmodulated, tone-modulated, or voice modulated signals . 2. COMPONENT PARTS All of the component units listed are irregular in shape; their significant dimensions are given in the following chart. Weight pounds 1.1 0.1 0. 9 0. 9 0. 9 0. 9 0. 9 1. 75 1. 75 2. 9 2. 9 0. 07 0.07 Height inches 2% Depth inches 4 3%6 3%6 3%6 3%6 3%6 31%6 31%6 1 1% 1 1% Width inches 4% 5112 5112 5Y2 5112 5112 1 1 Ys 1 1 Ys RADIO SET SCRAS.183 PARS. 23 Component Parts Dynamotor Unit BD-AS-83, includes Mount- ing FT-141 . . . . . . . . . . . . . . . . . . . . Radio Receiver BC-AS-229 (includes Mount- ing FT-99 ) . . . . . . . . . . . . . . . . . . . . . . . . Radio Control Box BC-AS-2 3 1 ( receiving) , includes Mounting FT - 1 1 8 . . . . . . . . . Radio Control Box BC-AT-2 32 (transmitting) , includes Mounting FT-118 . . . . . . . . . . . . . Radio Transmitter BC-AS-2 30 (includes Mounting FT-I 00) . . . . . . . . . . . . . . . . Complete set of Vacuum Tubes Consists of: 2 Tube VT-25-A for transmitter) 2 Tube VT-52 for transmitter) 1 Tube VT -3 7 for receiver) 1 Tube VT-38 for receiver) 4 Tube VT -49 (for receiver) The total weight of Radio Set SCR-AS-1 83 IS 39.04 lbs., exclusive of the cables. Weight Height Depth Width (pounds) (inches) (inches) inches 9.9 77i 6 7% 4% 1 2.0 7% 1 51%6 6Y2 0.9 2%6 4% 4 0.9 2%6 4% 4 1 0. 2 7% 13 % 6% 3. ADDITIONAL EQUIPMENT REQUIRED The following standard parts, not supplied with this order, are the minimum additional parts re quired for operation of Radio Set SCR-AS-183. Antenna Wire Cord and Plugs Cord CD-30 7 or Cord CD-307-A (Headset extension) FIGURE 2-JUNCTION Box TMAH172 (NOT FURNISHED AS PART OF SCRAS183 EQUIPMENT) 2 DESCRIPTION Headset HS-1 8 or Headset HS-23 Insulators J unction Box (furnished by airplane con tractor as part of the airplane) or equiva lent circuits Microphone T-1 7 or Microphone T-20-A with Microphone Amplifying Equipment RC 1 9-A Tuning Unit MC-1 25 (remote) Test Set 1-56-A is recommended for use In the maintenance of Radio Set SCR-AS-183. 4. POWER CONSUMPTION Radio Set SCR-AS-1 83 consumes 1 50 watts as supplied from the airplane. PARS. 35 5. DESCRIPTION OF PRINCIPAL COMPON ENTS a. Radio Receiver BC-AS-229 Radio Receiver BC-AS-229 is contained in a setbox which includes the supply and coupling circuits, tube sockets. power terminals and plug-in coil terminals, required for the reception of radio signals. I t is shown together with Mounting FT -99 and Coil Set C-43 7 in Figure 3. Mounting FT -99 consists of a metal frame with a shock-proof cup assembly 253 at each corner. Four snapslides on mounting brackets 284 on the receiver engage the four studs 2 7 1 which are molded in the soft rubber of the shock-proof cup assemblies. FIGURE 3-RADIO RECEIVER BCAS229 WITH COIL SET C437 IN PLACE 3 RADIO SET SCRAS183 PAR. 5 The receiver case 273 is of riveted aluminum hav ing one end blanked and the other end open. It has an opening in one side for the coil set and a second opening in the top (closed by tube cover 272) which allows access to the tubes. The open end of the setbox is closed by a metal panel 2 74 on which are mounted: Antenna binding post 84 Ground binding post 86 Input alignment condenser 80 and its adjusting knob 244 Dial gear unit 275 Receiver dial 240 Power plug receptacle 1 63. The internal frame or chassis of the receiver is permanently attached to the front panel 27 4. The case is attached to the front panel and various other points of the receiver and forms, together with the front panel, a complete shield closure for the receiver. Tube cover 272 is secured to the setbox by two snapslides 254. The tube com partment is divided into cells by the tube shields 2 76 which serv