Hitachi-DE7-tape-sm 电路图 维修手册.pdf

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1、t I I It Ii; i I t I _, # ffi, F So ffi s r rst - e-s#i I I EYK o rn o s o (a TO ILLLJSTRATIONS CASScTTE EJECT BUTTON CPERATION EUTTONS TAPE COUNTER/RESfiT BUTTON PCAK LEVEL IIJDICATOR DOLBY iR S/vlTCt DOLBY IlR 8/C SWITCH f4ULTIPI-EX IVIPX SWfTCH MICNOPHONE JACKS HehopHoNE JAcK OUTPUT LV.EL CONTROL

2、 KiiOB MONITOR SWITCH TAPE SELf;CTCR SWITCH ffECORDINC LEVEL CONTROL KNOB S iiEC MUTE BUTTON AUTO/TdAMORY REW S1f./ITCI-I TIMER SW1TCH POVER SWITCH FEATUfi ES i. 3-Fiead SYstenr for Metal TaPe 2. Sr:iit-ln DolbY lJ f; 3lC Circuit 3. Feather-J-ouch sivitches controlled puier I ogic gil6r-iit 4.Automa

3、ticCue,AuiomaticRervind Peet PiaYback in Accoriance with Re ad Out f rom Clmputer lviemeiY i SPTCI F iCATICIJS by lntegrateci Com- and Automatic Re Prese t Reryi;-rd Data g. Automatic Rec MUTr ro procluce Four second Elank Tape Fartion ai a Touch S. J-aPe StandbY Mechanisin 7 . Tape counter Automati

4、c ffeset Mechanisrir 8. Remote Control Jack g. Timer switch and Tape Selector switch lndicatcrs Track SYstem: Tape: Tape Speed: fiecording sysrern and Sias FrequeacY: 4. Erasing SYstern: Erase Ratio: FrequencY ResPonse: Signal to Noise Ratio: lnpurn SanritivitY ani lmpudanc: 4 track 2 channel stereo

5、 Cassette tape 4.5 crn/s AC bias, 85 kliz AC erase 65 dB (at i kHz) or rnore NOR-I: 2A Fa to i8 kHz 30 Hz to 17 kHz :3 dB) , CrOr -I: 2O Hz lo 2O kHr 3O Hz to 18 kHa t3 dB MTALIV: 2O l-iz to 21 kHz 30 Hz to 19 kHz r3 dB * Dolby B NR ON: 69 dB Dolby C Nff ON: ?5 dB Dolby NR OFF; 6l dB* A weighted, Re

6、f erence 39 T.H.D. fulicroPhon: O.3 mV tsuitabte rnicroPhone irnpedance 300 ohmr to 5 kohrns) Waw and Flutter: 0utput level and lmpedance: Oistortion: Crosstalk: Power Supply: Pcvrer Consumptlon: Dimensic,rs: . Weight: ,.: , -, According to DIN 45 5OO : Sr:ecif ications are sublect to periornlans ir

7、nProvet-nen t. Line in: 30 rF,V, 50 kohrns cr rnore 0.0360;l $JRMSI 0.1% L.ine out: 5O0 mV Su iiable Load lmpedance 50 kohrns or more) iieadphone: 80 rnV tSu itabie Lr:ad I mP*:dance B ohrns ttr 2 kohrns) 0.8% t1 kHz, 160 n!Yb/m) S0 dE tat 1 kHz) or.rnor* AC 1?OV, 6O Hz for U.S.A. *Y - 240V, 50 Hz f

8、or U.K- and Ausralia 2?W for U -S.A. - ?5!V or tJ.K. and Ausrralia 43Stvl x I iO1l x272D mm 4.6 ks change without notice for r1I II .t tI i 1 ! I I -.t sgffiffiffi# ffi$essffiYYffi T-lby B;. Play back with Daiby O F F and check th at the output dif ererice betwee n ilclby O F F and Dolby B. is appro

9、x. 10,JB. a Dolby C type : - 1 Record using rnetal tape M E C46 at 1 k H z. -4C dB with resoect to ttre tlolby level. Continu- ously record with Dclby OFF and Dolby C- tzl PlaVback with Dclby OF F and check that the output dif ference between Dolby O F F and Dolby C is approx. i6 dB- 6. Ccarse Adius

10、tment o Recording Level l ;. i tA tefi$d 5. .i% I Inpttt i trdiustnrent I i - i- value f_* -. -i-* I . DclbrY i n:io nrv to.z crg Lj.T-lg.rlc- trpe_i HLsci Adl.r*-ntl _f:jI_ _J 2i J ,qdj u strneni Pro ced ure Connect the electronic voltrneter to LINE OLJT, piayback the Dolby tape, antJ ad jr-rst so

11、that the electrcnic voltnrter reads the adlustrnsnt value. t2) Acijustrnent af Mete r 1) Connect the low-frequency oscillator to LINI lN th rough an attenu ator, and set the u nit in the re cord ing mode. 2) Set the rncnitor switch to the SOJ RCE position and apply a signal of 400 Hz to LtNf lN. Adi

12、ust the rneier usinq ihe attenuator so that the output voltage appeared at LlNf OUT is 520 mV *0.5 dB. 3l Adjust RTi02L and R so that the 0 dB point of the nteter correspc;nds to a transient point from OFF to Cftl. Adjustment e,f Bias Osciilation FrequeilcY l Set the iape selector srryitch to the ME

13、IAL position, and insert a fileas;uring probe in the terrninals of an erase head connectcr HP1. 21 Adjust L-50i so that the oscillatiorr frequency is 85 k lz 10.5 k Hz. Jvr4-rt- To the frequenc? counter 10ck a HP I 4. lnput 1u strnent rialu e j_ rzo fy -lo l_i_ lr?01f,-l Adjustment Procedure Connect

14、 the lowfrequeficlr oscillator to LINE lN and apply a signal _of 1 .2 kHz 50 as to initiate the recording mode. Then, set the rnCInitor switch to the logflgg position and acijust the output from the low-frequencY oscillator so that the voltmeter reads 520 mV *10 dB at tlre output terminal. Then, set

15、 the monitor switch to the TAPE position and adjust RT201 t- and R so that the out- put voltage is 52G mV -10 dB. rl 7. Fine Adjustment of Bias Current ustrnent I I oca iion Ad iu strnen t pot nt AA rrg. t t Ad jus trne n t p rocedu re within r0.5d8 | RT201L, ATT I wi th in + 1 .Oci8 within t3dB wit

16、trin t3dB within + l dB HITACHI f ETAL taPe 1 .2kl12k 1 .21:/12k 1 .2k /t?k MITAL 520rnV -?3dB RadioFans.CN 收音机爱 好者资料库 .I f.nd. s# *a i rd g*, I I td*d t, I re# Adjustment Prccedure 1 F ine ,ciju strnnr cf Eias Cu rrent t Connect rhe low-f reqilency oscillator -to t_lN f, lN- _ through the.attenuato

17、r and the electronic voltmeter ro LINI oL.T. Apply a signal of 1.2 kiz $ LINI lN to initiate the recording mocje. Tlren, set tlre monitor switch to the SoL, fiCE position rc ac just r-he output frcnr the low-frequency oscillatr:r so ihat the voltmeter reads szO mv -10 dB at LINE our. Ad just the att

18、enuator so that the electron ic volt- rrreter reads 520 mV -23 dB. 2l set the rilonitor :witch ta the TAPE position to alternately apply signals of 1.2 kHz and 12 kHz from the low-frequency oscillator. Adjust RT501 L and R so that a difference between the two outputs falls within +1 dB. only the chr

19、orne and metal tapes shor:ld be used for this check. Horryevcr, it the playback level deviates from t3 cjB, readjust the recording and playback levels ilsino the normal tape. B. check and ,Adjustrnent of cassette chassis section Check ltem i- Pt*trrt;pr-tr- f.; driving force : Adju:trnent of FlecorC

20、iriE Level 1 ) Connecr the k:rq-f re quency ascillator to L I N E lN and apply a signal of i.2 kHz to iniriaie the recbrd, ing rnode set the monitor switch to rlre scu RCg position to adju*t th* outprt frcrn the lo,*.frequefl- cy osciliator s(J that the v*ltmeter reacJs S20 m V -10 dB at LINE OUI-.

21、2l $et the rnonitor switch o ths TAPE position and adjust RT2c1L and R so that the electronic volt- mter reads 520 mV -10 dB at LINE OUT. 2 Reerence value ilmarks 330 - 420 gNote 1 . ;l i,:il ;,.*# ; *; Take-up torque35 - 65 g-cnr i FF torsue75* r R EW torque L_1!_110:l 6 I Supirly back-tensionjIgla

22、-*-l 2.5 * 4 g-cm i ftote 2. lnitiateplayback morJe 7 | Take-up back -te nsion 1 .l * 5 g-crn I trtote 3. lnitiateplayback nrode B I Spply braiing rorque Take-uir biaking torque 11 i0Head plate restoratiorr force Note 5. lnitiare stop rnode Allowable locking force I over 3C0 gNote 6. lnitiate playba

23、ck mode yppjv !:r.ig ,:lqiu _j_ l?-Jgg g : i igt- ake-uir biakirrg torque I 5C - 100 g-cm I Note 4. lniriate stop mode ad u rging Jorce _t_ .1 S : 25 S . i N;tu r Braking force Note 1Note 2 /7tuitr I i ; -r at a u | | ooooq : d ; O c o ! a I i ; -r 1, d ! | looooq t: 9oo+ _rg 3 Eh :r4 -rttxgR j?q ;I

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