BC-1335_Inspection_requirements_for_repaired_radio_1945.pdf

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1、. , SIGNAL CORPS . TgTIQ . , , NO. REP-255 29 Auuet 194.: SPEC1FICATION I . INSPECTIR!QUIREMENTS FOR REPAIRED -RWIORECEIVERAN.DTRSMITTERBC-1335-*L)- A. APPLICABLE SPECIFICATIONS A-1. The current issues of the following technical publications, or publications superseding th6m, form a part of this spe

2、cification. A-la. Specifications: Signal Corp Tentative 2713096 Radio Receiver and Transmitter BC-1335-(1) and Associated Equipment (For Radio Set SC-61 -(*) A-lb. Modification .Work Orders: Applicable Modification Work Orders pertaining to subject equipment. B. APPLICATION B-1. The following sct1on

3、a of this specificatl-.)n lt forth the minimum inspection requirements to be used in determinlns tre qu and without Wldtl.e force hein a ;Jnlied. D-ll h. Hold part 5 .11 rmly when enp, qeed. , D-12. M.uQ.ili.c:ation.iQ.rk Orier: Ap!)1 iceble Modi fi!:+ti.:m Jr,c Orers complied with. - , D-13. 1Qi:lt

4、.gr.g_q.T)t1Pnt: D-l3a T!le!e $hall be no bl .lshl:-w, milky appea :renfP, :; v El111g of the !_,rni.c;h filil . The vAnish shAll fri-.,1!1 . i . ,._. ,., the 5UrfRces of the equipment. D-lJb. The varnlhPd ufaces sEll be toue with hE hand. There hnll be no sticiness nd thP varnish SP 1 p tiloro.lghl

5、y cJrv . ClPA.r plastic insulito!s :!nd parts High-v)l tag c erami.c 1 Tl.SUl?. to s Open mvable electric cantcts l=lelay lOYltP.cts Variable capacitors Beri:-1g c-u:rfaces whose eectricRl anti/or 00Prat1,n will he afrpctrl hy thP An1i the coati m.st.eria1. I!J( ,. ,., ! _i . . t . ( . NO. REP-255 l

6、J I II REPAIRED RADIO RECEIVER AND TRf.ISHT BC-1335-(*) - - D-13d. Each unit of equipment thot nee: :-.Pcn rroitu,.P ;:.n fungus proofed shall bear a marking rPning MF?1 F.nrl th- d11.te (month and year) of treatment. The dat.e c:h 11 be accurate to within 0ne rnonth. The mJ!J.h .nCo ver rray t( abb

7、-reviated. The marking shall ap:-.e:;.r on thf oytlior of th case ann on the cha5sis of th;, omn0:f21t fn0+-, on c:t contr0l pnn.el) A ubber tnfl n 18 rking o . a f e 8.1 nrnnia l nbel is ncceptable. D-14. IountlWLof Pa.ru: D-l4a. No sharp prot-rding edgPs Jn hJlts or cres. D-14b. No bd)y lont t e p

8、roper rem0val of the holt or screws. D-l4c. Nuts tigl-tt and having no VJ0:Tl d.ges tht couln T . . ., their easy rP.oval. D-14d. Bolts md screws equipped with vac;hers. D-lle. Rivet ends well -rolled. or oun. D-14f. Riveted, bolted nd screwed-on cart shAlt hold tightly wen tested by ann or ith a su

9、itble o!Y bar. D-15. Namep91P.s_Marines g_tnillie: D-15a. Securely fastened or !narked in proper locatt0n. D-15b. 1feat, correct :Jnd c1 early le-gihlP. D+l5c. Ctrcit symbol on or adjacent to AsigntP r L _ except v;here pace d?es not permit. D-15d. Transparent, protective coatine coverig ink, un P.

10、s inkis waterproof. D-16. P: Parts confor.mine to fpPctfictlon 271 309h, or to te current applicable highr echeln spare oart ltt. D-17. Plugs nd Pecptales: D-17a. Secu:rely attached to equipnent. D-17b. Threads clean and not stripped or crossed. Sheet 4 of 9 Sheets - f il NO. PEP-255 Sheet ; RPAIFFD

11、 RADIO FECEIV1:R AiD T-:i.NSITTFR BC-1335-(*). -. -. - D-l?c. Insulation in good condition. D-18. PlJJl Dyi.es: I - 1 8-n. Tubes and nther parts firmly sea tee. D-l8b. Flectrical contact at all required points. D-l ched to terminal :locks or st r1 ;:J. n-3. 1.;:1: D-?3d. As llttle bare wire es pract

12、icable extending hey,Tln any insulation. D-:?3b. Vi res seen rely at tacheJ to terminals by -.eing th ;( .ic thr0ugh or a.r.:und them. n-?3c. No hro.o:en w1 rP.S noJ strqnds. D-3rt. No (r r-rosion, peelint:, flaking, hare Sot:, ?l).,. n1., . e in tinning or in other prJtetiJe coating on b.-_re ,-i D

13、-23P. No ;,harp bends_ , p.s.rticularly where wi:r:-connP t +-(1 plastic or ceramic parto ann 1n r-f circuits. D-23f. V1ires dressed a.t:iY frorrt 1r.:.at -llssi9atin!: )rt, ., n practic9.ble. D-23g. Suffiient cleArAnce at Rll points to re7n ny ln- desired elctrical or echani al contact. D-23h. SleP

14、vin. )n :i.re ,.:vre th8rt is dar1gP! Jf ld.ng m unesied electrical cont1ct. D-31. Sufficient slc:icl-c in wlring to pPrr.llt ,.PT.)!;_ )f 2D/ part xcept in aSP.S where t1P. snHtlleS )f ()1 ,P-t-l.n 1; is of rime im:o:-tncf3, such qg i.n high releny r-f ,.,.;,_;-. d+c-. D-23j. ririn: 8S short :15 i.

15、s consistent wlth mP.P.ti1 :r,l J . , or requiemants f tis pragrph. D-:.,a. Cle rly and l!mn ) 1 8tely 1110. r1:e(1. D-2./.,b. Securely t t:-. che.J t: !:)ntr.:Jl s 1wft. E. ELECTPICJL REQUIRF:M.:NTS F.-la. At normal room te!lJcrattlre. Sheet 6 of 9 She?ts r ). . . . NO. REP-255 REPAIRED RADIO RECEI

16、VR D TRfliTTER BC-1335-( ). -. _ -.-.-. . - -. - E-lb. The input supply voltage shall bP. of suf!icit.=?ni-r1te to produce plate and filament supply voltage itroin tn following limits, but shall be betreen 5., and 7.-v: . , . i.th the 6V-12V switch in 6V posl tion or bet7iePn ., 0.$3 tncl 1 -volt- w

17、ith the 6V-12V_switch in 12V p0itton. Transmitter Plate Voltage Transmitter Filament Voltne Receiver Plate Voltage Beceiver Filament Voltage 1:?0 4J) 85 2.7 E-lc. The set shall be properly aliened. t) 6V-1.2V svit 1n 6V position nd with 6.0 volts d-e input, the out,)1.lt 11Jlge t.1e power supply sha

18、ll be within the following limits: Recei ver Plate Transmitter Prate Receiver Filament Transmitter Filaent 85 to 95 volts 115 to 130 volts Ze5 to 3.3 voJts 3. to /. B volt c: E-3a. This test shall be repeatert .d t;., the AV-12V c t J.1 l 12V position :1nd with 12.0 volts d- e input. The ) ;.ut 0Lt

19、ages shall be within the abov limits. E-4-D.Q. AmP.l:tfieClain;. A change 0f volt!:lgP of 0.1 uo1t t the dJ scrlminator output (in no. 3 of the rlicrirpinR.to:r t11hP) MITTER BC-1335-(*) o outputo If the latter method is used, the discriminator output 2.1all first be grounded and the grid voltage to

20、 the modulator atusta to between minus 7 and 12 volts with potentiometer R-48o E-5o Sen3itivity Test: The sensitivity of t . e receiver shall )6 measured at 27o0 mco and. 38o9 mea, tmrl snllll be -suqh that an input of 20.m1crovolts or less applied to the antenna terminsl through a 1800 ohm, non-ind

21、uctive resistor shall aeliver loO volt on the limiter grid. E-6. Discriminator Test: The discriminator shall be tested by connecting a signal generator to the signal grid of the mixer tube through a OoOl mfdo capacitor and by measuring the olscriminator out- put at pin noo 3 of the discriminator tub

22、e The Lgnal genertor shall be adjusted to provide 10 volts on the llmiter grid.o This signal gen- erator output shall remain unchanged throughout the remain er of the test. The following values shall be obtained: E-6aa With the frequency of the sinal generator 9et at 4ov me., the discriminator volta

23、ge shall be zero plus cL 111tnus Oo volt. E6bo With the frequency of the signal generator 25 kco above 4o3 mco, the discriminator voltage shall be minus 5 volts or more a E-6co With the frequency of the signal generator 25 kco belo 4o3 mco 1 the discriminator voltage shall be plus 5 volts or moreo E

24、-6do The difference between the values of the ciscr1minato V9ltage, without regard to sign, as measured under the condit- ions speci fled in E-6 b and E-6 c above, shall be no greater t.b n 2o3 oltso E-6eo The frequency of the signal generator shall e varied above and below 4o0 mcoto deternine the m

25、aximuo volter., neg- ative a.nd positive wnich can be obtained at the uiscrin.1nator outputo Ttle signal generator frequencies corresponuing to teso maximum voltages shall be separated by not less tnan ? c. E-7o IF selectivity Test: ;. signal generator shall he connected through a 0:01 mfdo capacito

26、r to the signal grid of the mixer tube 6nd set at 4o3 mco The signal generator output shall be aujusted to obtain 1,0 volt on the limiter grid. The signal generator output volta e shall then be adjusted successively by 2 and 10 times that valueo For each such value of signal generator output, the fr

27、equency shall be varied both sides of 4.3 me. until the voltage on the limiter grid returns to 1.0 volt. The band width between the two points, one each sine of 4.3 me., shall be as specified below: Sheet 8 of 9 Sheets Sheet #9. REPAIRED RADIO RECEIVER AND TRANSMITTER BC-1335-(*). INPUT 2 times norm

28、al 10 times normal TOTAL BAND WIDTH IN KC MIN. MAX:- 35 65 35 145 E-8 Aud1o Qg:tot Test.;_ With an audio oscillator delivering a 1000 cps signal of 2.7 volt! to pin no. 3 of the discriminator tube, the audio output into a 4000 ohm load shall be not less than 15 milli- watts. E-. lxansmitter PowrJlut

29、put: Transmitter power outuut shall be measured at 27.0 me. and 38.9 me. by connecting an r-f millameter in series with a 73 ohm, non-inductive resistor across the 73 ohm outp11t of the transmitter. A variable capacitor of approximately 100 mmf. in series with the dmruny antenna may be used, if nece

30、ssary; and shou d be adjusted for maximum indication on the r-f milliameter. The r-f current shall be measured and power output determined by r2R, wl:lere R is tle sum of the resistance of the meter and 73 ohm resistor, and I 1s he r-f current. The power out: ;)ut shal l not be less thah 1.25 watts.

31、 During this test, the antenna loading circuit shall be disconnecte from the final tank coil. E-10. MQdUlatiQn Canabilitx: The frequency deviation of the transmitter shall be tested at 27.0 me. and 38.9 me. A change of grid bias on the modulator tube from minus 8 volts to zero volts, or from minus 8

32、 volts to minus 16 volts, shall produce a change of frequency of not less than 25 kc. or more than 75 kc. E-ll. With the ALIGN-OPERATE switch Sft to ALIGN and with a voltage of between minus 4 nd m-t_nus 8 volts applied to the receiver-transmitter test prod, it shall be possible to close the eye of

33、the indicator tube by adjusting the VOLUME ontrol. E-12. Operational Test: Radio Receiver and Transmitte BC-1335-( ) shall be given an operationa1f test to determine that the equipment is functioning properly. This test shall be performed utilizing a test radio receiver and transmitter. SignRls rece

34、ived and transmitted by the set under test shall be clear and intelligible. F.xtraneous noisPs, intermittent or microphonic conditions shall not be present when the set under test is either tapped several times with a padded mallet to simulate vibration or is operated on a vibrating table for at least thirty seconds. NOTE Copies of this specification for the purpose of bidding on the repair of the equipment covered should be obtained diect from the Philadelphia Signal Corps ocurement District, 128 North Broad Street, Philadelphia 2, Penna. Sheet 9 of 9 Sheets