Summary of the content on the page No. 1
Sefvice nual
FM
Ouartz Locked
STEREO RECEIVER
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Summary of the content on the page No. 2
I MODEL SX.38OO COMES IN FOUR VERSIONS DISTINGUISHED AS FOLLOWS: Type Volt4e Remarks ; KU 120V only U.S.A. model t (Switchable) s/G 1 10V, 120V, and 22QV, 240V U.S. Militarv model (Switchabte) s 1 10V, 12OV, 22OY and 24OV H , General exDort model l20V only KC Canada model H r This service manual is applicable to the KU type. When repairing the S/G and S please Wpe, -p571. the additional see service manual 47 When repairing lp the KC type. see the a- olease H dditional service manual (AR
Summary of the content on the page No. 3
I 1. SPECTFTCATIONS I Tone Control Ampl if ier Section Power (100H2) tSdB BASS . t r',l0dB(10,000H2) TREBLE ..... per Power chan- Continuous 0utput of 60watts* (-6dB/oct.) Subsonic Filter . 15Hz 20Hertz to 20,000 nel, min., at Sohms from *40d8 (Volume position) Loudness Contour control set at harmo' Hertz with n0 m0re than 0.005% total (100H2),+3dB (10,000H2) +6dB r . . . . nic distortion, (lHF, Noise short-circuited, A network) Hum and PHONO. .....82d8 (20 Hertz, Total Harmonic D
Summary of the content on the page No. 4
Eix-3El00 I AM Tuner Section (lHF, Ferrite Sensitivity antenna). . 300pV/m t Ext.antenna} . . . 15pV {lHF, Selectivity .....30d8 Signal-to-NoiseBatio .... 50dB r| lmageResponseRatio ... 40dB lFResponseRatio.. .... 40dB Antenna .... Ferritelooostickantenna r| Audio Section ( Output Level/l mpedance) FM(100%Mod.). kilohms ..... 650mVl1 t . ..... AM(3O%Mod.) 200mV/1kilohms Semiconductors fCs... .......17 t FETs. .......6 ...,.71 Transistors Diodes .......58 t Miscellaneous PowerRequirements .
Summary of the content on the page No. 5
t 2. TRONT PANEL FACILITIES T t t r I t POWER SWTTCH c TTU STEREO O INDICATOR Set this switch to ON power to supply to the receiver. This indicator lights up when receiving an FM t stereo There will be a short delay when it is set to ON, because program if the FM muting off switch is released. the muting circuit has been actuated to suppress the ,o SIGNAL INDICATOR unpleasant noise that is sometimes generated when the power is This indicator r switched on and lights
Summary of the content on the page No. 6
r-- level program signal on the air next to a station whose MONO. lf the sound appears be louder on the right, it to you want to receive. you may not be able to tune in means that the volume of the right channel is higher. satisfactorilv because the sound will be drowned out Turn the balance control to the left and adjust. Con- by the stronger signals. ln cases like this, set the FM versely. if louder left, the sound appears to be on the it position) MUTING OFF switch to OFF and {depressed
Summary of the content on the page No. 7
I six-3aoo t BLOCK 3. DIAGRAM t R F Block rc { PA3007-A ( ) rc PA4O06-A l t HA120r rC { ) OU'TPUT L 75nO .t I R :cono o t 5r€ffEO !NOlCnI0R 6 !5 eS I i'"l i,-qilgl ovaRTz locKf,o ril9rcaToR t-POrtT StcxaL j llO'a.AtOA 0AtvE ' 16l laraMe l- rvo- -l)l lFv/tp'tq l-- * ,r dve cfrfc-.,a I I | I l[-ll- -rr- I | lhTjl 'r r'-; I l-68{"-l;;l I;;;;l-, ':re I [Jl lf I PFrscalla 1 l_ t *F;'* 1 FM..id l,rEr, I 1 I _T-- I \1,F 0FFSET .J AOJ, I 46.468 AUD IO l I UUIINO lOW FILTgF ,T I ; a :,
Summary of the content on the page No. 8
T 4. DESCRIPTIONS CIRCUIT t deterioration in separation at the 4.1 FM TUNER tor, there is no low frequency end. Front End Besides the decoder and muting circuits, the The FM front end of SX-3800 includes a 3 t pilot PA4006-A also incorporates the signal cancel- ganged tuning capacitor, a dual-gate MOS FET- ivluT ler, stereo auto selector, VCO killer circuit, equipped L-stage RF amplifier, and a modified amplifier, and MUT control circuit. Clapp circuit local oscillator. This oscillator is a
Summary of the content on the page No. 9
sx-gaoo T (C) stage is reduced, and the reactance of the in- 4.2 AM TUNER ductance stage (L) t increased, resulting in AM The AM tuner section consists of a 2-ganged detection by D2 which leaves the positive portion tuning plus capacitor an IC (HA119Z) which con- of tlie IF signal. If the input frequency decreases, L tains a l-stage RF amplifier, converter, 2-stage IF stage reactance is decreased and C stage reactance amplifier, r detector, and AGC circuit. increased, resulting
Summary of the content on the page No. 10
SEGM€NT DRIVER OIGIT ORIVER MU !TI PLE XER I PRESETAEL€ 5-DIGIT OECIMAL COUNTER I 22-8lI r 16 ROM I GND Fig.4-5 Block diagram of PD5009 I Inl val. Pin PD5009 no.? of is the brightness selector lttr- o,w terminal. The pulse time division width is set to I 8009s H level for input signals, and to 200ps for ooM L level signals, thereby varying the degree of FL tube brightness (by varying the segment lighting period). Note that pov.er FL since the indicator I *l-w (DlM) 8C= L tube is driven b
Summary of the content on the page No. 11
sx-g€too r SIGNAL lndicator Circuit r t T l| t t ll Fig. 4-7 SIGNAL indicator drive circuit The SX-3800 SIGNAL indicator SCHMITT consists of an CIRCUII t FL tube 5-point indicator display. The signal meter drive signal obtained from the FM IF system IC (PA300?-A) and AIVI tuner IC (HA119?) is first amplified and then applied to the indicator t drive (PA30(r/-A rc ) IC (HA12010). This IC contains 12 pairs of voltage comparators similar to those employed in the power
Summary of the content on the page No. 12
t on the other hand, the broadcasting frequency is 4.5 TONE CONTROL AMPLIFIER approached from iow frequency (or the side when This circuit is an NFB type tone control ampli- t tuning away to a lower frequency) pin the no.4 fier with performance IC newly developed high voltage will be lower, resulting in being tumed Q22 iHA12017P). (left on to light up the lower frequency hand side) 4.6 POWER AMPLIFIER detuning direction indicator. When either or Q22 t Amplifier Circuit is on, the base volt
Summary of the content on the page No. 13
sx-3aclo r excellent high frequency characteristics compara- When points Z in- the voltage across X and is ble lo those of a small-signal Further- transistor. creased positive portion ap- by tl're of the signal I more, becanse lhere is no time clonstant NFB in the plied to this circuit, it becomes the input signal circuit ir-r the lorv-frecluency region, amplification (Q1). of this emitter-follower Since the emitter- is possibie (DC dorvn to DC inputs will be cut off, gain practically fo
Summary of the content on the page No. 14
t 4.7 POWER ]NDICATOR CIRCUIT t ic ('tA73t8P) t/? HOLO & rN s16NAL o*-l OC AMP t H L€VE L SHIF I OFFSET COM. r| PENSAIOR I t F/LAMENT Fig. 4-12 Power indicator t circuit power The SX-3800 output indicators feature PROTECTION 4.8 CIRCUIT (FL fluorescent indicator tube tube). In this tube, The purpose protect of this circuit is to the t thermionic emissions from the cathode are ac- speakers power The relay in and the amplifiers. the celerated into the fluorescent substance of the in outpu
Summary of the content on the page No. 15
J six-gaoo r Overload Detector The overload detector circuit incorporates the F load (RL) in one side of a Wheatstone bridge. The base and emitter of a sensing transistor (e1) are connected to the opposite corners of the bridge, T so if RL decreases, will become forward Q1 biased. If RL falls below a prescribed value, will turn e1 on, thereby C1 will rapidly discharge. As conse- quence, r will turr on and Q4 the relay will become deenergized, thus causing the output cir
Summary of the content on the page No. 16
DISASSEMBLY 5. Bonnet Case side of the screws ot each Remove the two O bonnet case. i Plate Bottom detach the fifteen screws to Remove the O plate. bottom I Panel Front push knobs except the all control Remove and two nuts the two screws t knobs. Remove @ front from the Panel. Q l| case Bonnet I t I t $\ f\,.\ t plate Bottom A\ l s\$ Front panel I t I I T I to t I
Summary of the content on the page No. 17
sx-gEloo ! parts : marh on sotne camponent indicates The fi found PARTS LOCATTON 6. part. the importance of the sofety of the There- factor I parts replacing, be sure to use of identical when fore, designation. Front Panel I knob B Push AAD-227 panel Front assembly- I AN 8.851 AAA.O66 AAD,226 Knob AAB.24O Lever knob AAB-239 Front View with Panel Removed Fluorescent indicator tube Fluoresc€nt indicator tube AAV-OO7 AAV.OO9 push - Remote swirch (SPEAKE RS) Dial shaft assembly t7 ASX,13
Summary of the content on the page No. 18
sx-3Etoo P.C. BOARD CONNECTION DIAGRAM TUNER Ass'y UE GWE-133 r+ I i s,rrprro&ffi i | E?E-il-.---'ffi:tlJr, I "i;;:ii liut .t rl==I tfil "',s|il,f ffii III +",:r- '*i'' ,o,@ ' I 7** l:t'; I nl ' *l; ,11",i l.i r-'o $' r*'i; .{i,,"r- *i"a iJ ffi | nnij:j :',Slt, uJ,,tl '1,r, =l ii-ll-.1 rsHr:tj-l:f +t ts--lrg< I lil't r l' ffii,i{ li lr *B ;;f "t lrl | i;fi!f*l:lH:ftfi=_t;1 ll #"ij"ffii iiii'{t5h lo o ( ilc \, 9'o" f"lll*l Cltlctil *r- -r\'& tlrr .fn I' jt'i wC ilu
Summary of the content on the page No. 19
EOUALIZE - 22' AWM SWITCH Ass'y GWS-146 I hnl I ll l:1,1 { i ltfil i lill D!*ll+h llil Ass'y SWITCH Olt! GWS-226 rst t5 5 lS2a7J a? PLIO (STEFEOI 8V 5OmA ls '*l { *i* 6 .+,*, 1 l* I Itr T I i I r.rr: tn i.ls, o ho 7 98 rz |t'hrribE I I lll|Lus I llr I I ?/ ",, I *t++v 'rr I rll*ll/ 'd16l u.1 mf \ 1 'li? | le's a[{,r r t i'!; l-ilL r. *.- t iT'it t l' ' *i I it f* W*l'' '*i,lr I ll ttr 4 &rsn re.dl I t ( llilli $ll 1';rl rnl nl ilIl t_ &H&h I ll I I tltti ltttl _l r I a I
Summary of the content on the page No. 20
six-3E|c'c' h I E0UALIZER Ass'y AWM-227 I The counter IC (PD50A (AWV-009) has been des @@ 'BgOUI values by appropriate co 'a. I crI or L leuel .119 signals) applier t =.d l.i;' the wiring (connecting within the equalizer ass at differ slightly the ci from r I rl grade the of the FM cet t- I ti into ranhs I 3 accord.ing to , The R28 and. R29 resist t ( AWM-227 ) constitute tht I I { match the counter IC (PI f'., I assembly) with the FM I tii'; haue been arranged accor l"' - t mi
