BC-659A_J_repair_instructions_TM11-4023_1945.pdf

《BC-659A_J_repair_instructions_TM11-4023_1945.pdf》由会员分享，可在线阅读，更多相关《BC-659A_J_repair_instructions_TM11-4023_1945.pdf（63页珍藏版）》请在收音机爱好者资料库上搜索。

1、 . _,.,., . - i(lrt , , .11S.lORCAU_ . W A R DEPARTMENT TECHNICAL MANUAL RADIO RECEIVER . AND TRANSMITTERS .,. . . BC-659-A, -B, -H, AND -J REP AIR INS1RUCTIONS STRICTED MATTER. n MINATION OF RE. rode or position S1t1u . DISSE oeY by virtu of hts ter . . such aer n is enttted s . f casstfied rna tfi

2、cia duheS No perso sesston o whose o h to (nowedge or pots those individa s See aso paragrap t d ony 0 sesston. is entrus e k ow edge or pos March 944.1 require such ;3b, /J,R 3So-5, S . WAR DEPARTMENT JUNE 1945 WAR .DEPARTMENT TECHNICAL 11ANUAL I TM 11-4,023 RADIO RECEIVER. AND TRANSMITTERS BC-659-

3、A, -B, -I-I, AND -J REPAIR INSTRUCTIONS Clt.S:/,.,:,.,1 C ., :c:tlED CHANGED TO tJNCX.- . y AUTHOP.I Y OF 7-. !_jt._-.!;,- /-tl Af2-e.i ;(.(pI . qDEPARTMENT JUNE B;iilll:_.-1 1! !. . :. 1/SSEMINAT/ON OF R MATTER. No person is entitled solely by virtue of his grade or position to knowl- edge .r posse

4、ssion of classified matter. Such matter is entrusted only to those individuals whose official duties require such knowledge or possession. (See also paragraph 23b, AR 380-5, 15 March 1944.) U11ited States Govemt(IC1ZI Pri11ting Office W aslzitzgto11: .7945 , . 194 5 WAR DEPARTMENT Washington 25, D.

5、C., 22 June 1945 TM 11-4023, Radio Receiver and Transmitters BC- 659-A, -B, -H, and - J, Repair Instruc- tions, is published for the information and guidance of all concemed. AG 300.7 (31 May 45) BY ORDER OF THE SECRETARY OF WAR: OFFICIAL: G. C. MARSHALL Chief of Staff J. A. ULIO Major General The A

6、djutcmt General DISTRIBUTION: , AAF (5); AGF (5); ASF (2); T of Opn (5); Dept (5); Base Cornel (5); Island Comd (5); Def Comd (2); Arm S Div ASF (1); Tech Sv (2); PC PE (2) . Dep 11 (2); Gen Oversea SOS Dep (2) ; Pro Dist 11 (2) ; Gen USM:A (10); WDGS Lib (5); Lab 11 (2); Rep Shop 11 (2); A (5); CHQ

7、 (2). Three copies eac to the following T/ 0 11-15; 11-47; 11- 107; 11- 127; 11- 147; 11-587; 11-592 ; 11-597. Refer to FM 21-6 for explanation of distribution formula. II CONTENTS Paragrnf!lt Page SECTION I. DESCRIPTION OF RADIO RECEIVER AND TRANSMITTERS BC-659-A, -B, -H, AND -J. General . , . 1 1

8、Over-all system function . . . 2 a II. DIFFERENCES BETWEEN MODELS. Operational differences . . . . 3 G Design differences . . . . . 4 6 Ill. INITIAL REPAIR PROCEDURES. General . . . . . . 5 7 Tools, test and cleaning equipment . . . . . . 6 7 Disass mbly for inspecting and cleaning . . Cleaning and

9、inspecting of chassis . . . . 7 8 8 9 IV. PRELIMINARY TROUBLE-SHOOTING PROCEDURES. General . . . . . . 9 11 Returning chassis to housing . . . Input resistance check . . . Operational test . . . . . . 10 11 11 11 12 11 V. ALIGNMENT PROCEDURE. Presetting . . . . . Alignment inclicato1 . . . . . Prese

10、tting procedme using alignment indicator . . . . . . . . I-f and discriminator alignment . . Neutralization . . 13 1? 14 15 15 15 16 16 17 17 VI. DETAILED TROUBLE-SHOOTING PROCEDURES. Signal substitution . . Normal point-to-point resistance values . . Moistureproofing, fungiproofing, and refinishing

11、 . . . 18 19 19 22 20 23 VII. FINAL TESTING. Alignment check . . . . . I-f selectivity test . . . . . I-f rejection ratio test . . . . D-e amplifier gain test . . . . Image rejection ratio test . . . . . . . Receiver sensitivity test . . Audio-frequency response t st . . . . T ranfimi tter power out

12、put . . . TransmitteL neutralization . . . . . . . . . 21 2i 22 25 23 25 24 2!5 25 25 26 26 27 26 28 26 29 26 VIII. INDIVIDUAL STAGE AND CIRCUIT REPAIR DATA. Filament circuit . . . . . 30 28 Receiver r-E amplifier No. 1 . . R-f amplifier No. 2 . . . . . . . Receiver mixer stage . . . Receiver crysta

13、l oscillator stage . . Receiver i-f amplifier No. 1 . . . . . . Receiver i-f amplifier No. 2 . . . Receiver limiter stage . . . Receiver diode rectifier and d-e amplif1er discriminator . . 31 28 32 30 33 32 34 34 35 36 36 38 37 40 38 42 Receiver audio-frequency power amplifier . . . . Transmitter re

14、actance modulator . . Transmitter oscillator . . 39 46 40 48 41 50 Transmitter buffer . . . . Transmitter r-f power amplifier . . . 42 r-2 43 54 Ill RESTRICTED SECTION I DESCRIPTION OF RADIO RECEIVER AND TRANSMITTERS BC-659-A, -B, -H, AND -J* I. General c. UsE. Radio Receiver and Transmitter BC- 659

15、-(*) is designed for short-range two-way voice communication. It is a low power, port- *See TM 11-615 for installation, operation, and other maintenance data on this equipment. able, frequency-modulated radio receiver and transmitter. b. RANGE. The set is designed to operate over distances up to 5 m

16、iles. The maximum range will be greater when operating from an ele- vated position. Figu?e 1. Radio Receivm and Tmnsntitte1 BC-659-(*) . . i I - I I by the antenna, and resonated in the power- amplifier (p-a) plate tank circuit. It is im- pressed on the control grid of first r-f ampli- fier tube VT-

17、179 (V5) . It is further amplified by second r-f amplifier tube VT-179 (V6).The resulting voltage is impressed on the control grid of mixer tube VT-178 (V7) . Crystal-con- trolled local oscillator Tube VT-185 (V8), operates on the fourth harmonic to produce the i-f beat. Two stages of i-f amplificat

18、ion are inGluded, using tubes VT-179 (V9) and VT- 179 (V10). The arvplified i-f signal is im- pressed on the -grid of limiter tube VT-179 (Vll). This stage eliminates the amplitude variations present in the signal, and feeds the signal into tube VT-177 (V13) and VT-183 (V12) in a conventional discri

19、minator circuit. The triode portion of tube VT- 177 (V13) is used as a d-e amplifier. The resulting audio signal is fed into output tube VT-185 (V14) . For use of d-e amplifier (V13) see c below. c. TRANSMITTER. (1) The transmitter con- sists of a reactance modulator, tube VT-185 4 (V 4), an electro

20、n-coupled oscillator, tube VT- 185 (V3), a transmitter buffer-doubler, tube VT-182 (V2), and an r-f, p-a tube VT-182 (V1). (2) The oscillator is designed for good sta- bility over a wide temperature range. It uses an LC circuit in conjunction with the reactance tube to control its frequency. A porti

21、on .of the transmitter signal is feel back into the receiver and since the receiver is crystal controlled, the transmitter frequency is made to follow any frequency change that appears at the receiver input. The bias produced by the d-e amplifier tends to hold the transmitter frequency con- stant. (

22、 3. ) The doubler input circuit is tuned to twice the oscillator frequency and therefore amplifies the second harmonic. The output tuned circuit is tuned to twice the amplified signal or four times the oscillator frequency. The resulting voltage is amplified by the r-f power amplifier and passed to

23、the antenna. SECTION II DIFFERENCES BETWEEN MODELS 3. Operational Differences There are no operational differences in the models of BC-659-( *). Figme 4. F1o.nt Panel, Radio Receive1 ancl Tmnsmitter BC-;659-(* ). 5 I I 4. Design Differences a. In Radio Receiver and Transmitter BC- 659 manufactured o

24、n Orders No. 16130-Phila- 44 and 16129-Phila-44, capacitor C72 has been replaced by capacitor C76, 0.03 micro- farad (mf), 400 volts direct current. The out- put transformer has been changed to provide an extra impedance matching tap to accommo- date a 250-ohm load in addition to the 4,000- ohm load

25、. A label located on the outside chassis wall indicates the manner in which the change of impedance should :be made. A reversible metal tag is mounted near the phone jack to indicate the impedance connection. All im- pedance changes should be accompanied by a b corresponding reversal of tag. b. All

26、Radio Receiver and Transmitters BG- 659-A, -B, and -H are to be modified by the addition of a loudspeaker cover (6C18) in ac- cordance with MWO SIG 11-615-3. All other models of BC-659 will be equipped with the above-mentioned cover. c. All Radio Receiver and Transmitters BC- 659-A, -B, and -H are t

27、o be modified to .incor- porate Adapter M-399 in order to permit use of the meter and the receiver amplifier, .tube of the set for alignment procedure. The BC- 659-J will be equipped with Adapter M-399 by the manufacturer. SECTION Ill INITIAL REPAIR PROCEDURES 5. General Note. Before making any repa

28、irs or any adjustments, all authorized Modification Work Orders should be ap- plied. See FM 21-6 for list of applicable Modification Work Orders. Maintenance personnel should follow the pro- cedure outlined in this manual when repairing and overhauling Radio Receiver and Transmit- ter BC-659-( *). T

29、he repair information in this and the following sections is presented in the order in which the repairman should actu- ally perform the various operations in the re- pair shop. This procedure permits repair of the equipment in the shortest time possible, result- ing in sensitivity and selectivity co

30、mparable to that of new equipment. 6. Tools, Test and Cleaning Equipment . The following items should be available for re- pair of this set. Table II Item Assorted hand tools. Insulated alignment tool (provided with equip- ment). Soldering iron and solder. R-f signal Generato1 . . A-f signal Generat

31、or . . Alignment Equipment ME-73-(). Maintenance Equipment ME-13-C:) . Solvent, Dry-cleaning . Assorted brushes. Pipe cleaners. Clean cloths . . Sandpaper . . 1 Crocus cloth. Description .Covering the range 4.0 me to 40.0 me. . Covering the range 250 cps to 3000 cps. Approved symbol ( SD). Lint-free

32、. #0000. Figure 5. Removing chassis /?om housing, Ra.dio Receive? and Ttansmitte? BC-659-(* ). 7 I I / 7. Disassembly for Inspecting and Cleaning a. CHASSIS. Remove the chassis from the housing by opening the tension clamps on either side of the operating panel. The radio receiver transmitter can th

33、en be slid out from the hous- ing. u. DESICCATOR. Remove desiccator by remov- ing the four binderhead screws holding the per- forated desiccator frame. c. CRYSTAL REMOVAL. Remove both crystals from the chassis by lifting the crystal retaining spring. Fig1 .we 0. DesicoatmJJosition in Radio Receive?

34、ancl Tmnsmittel BC-050-(* ). t d. REMOVAL OF TUBES. The removal of the lock-in type of tubes as supplied with the set re- quires a special techn!que to prevent possible crushing of tube and injury to the hands. To remove, grasp tube firmly, rock it back and forth in the direction of the tube socket

35、mount- ing screws and pull upward. e. INTERNAL BATTERY REMOVAL. The battery box is located pn the transmitter side of the radio receiver tnd transmitter chassis and be- hind the front control panel. The cover plate is held in place by four binderhead screws, two on the top and two on the left side.

36、The removal of the battery will necessitate the 1emoval of the four screws. 8. Cleaning and Inspecting of Chassis a. CLEANING OF MAIN CHASSIS. Chassis must be clean and free from rust and corrosion. Blow Piume 7. Removctl of inwrwtl baUc?y uf Radio Receive? a11d 1ruusmitter BC-ii50- (* ). Figwe 8. A

37、ntenna cottpling, Radio Receive1 cmd Tmnsmitte1 BC-659-(*). out all dust and dirt using clean, dry com- pressed air. Use solvent applied with lintless cloth, brushes or pipe cleaners. Caution: Do not attempt to remove tarnish from silver-plated switch contacts. Remove rust and corrosion with a stiff

38、 brush and solvent. Heavier rust and corrosion may be removed by careful use of crocus cloth, solvent, and com pressed air. 9 b. INSPECTING MAIN CHASSIS. After cleaning the set, inspect the chassis to determine the exact model. Check to see that model has been modified as required. During inspecti_o

39、n a care- ful check must be made for any ev.idence of temporary field repairs. All electrical compo- nents must be free from obvious mechanical and electrical defects when inspected visually. .f.-ny part, the fcilu1e of which was obviously ca.usecl by an elect?ical fault, must not be re- placed unti

40、l ci1cuit is ch eckecl ancl case of fail- ure is clete1 minecl. (1) Wiring. All soldered joints must present a good mechanical and electrical connection. Wiring insulation must not be worn or chafed. INsulated tubing must not be torn or missing, and bare wires must not be shorted to chassis or other

41、 parts. The chassis must be clean and free from corrosion. (2) Housing. The housing must not have cracks or breaks in the metal. It must be free from corrosion. It must not be scratched, and must have no outside unpainted areas. (3) Spe(Lker shielcl. The set should be in- I ( / spected to determine if the speaker shield has been installed in accordance with MWO SIG 11- 615-3. It should be actuated by the lever to de- termine