User manual PIONEER SX-450

[. . . ] B L O C KD I A G R A M C I R C U I TD E S C RP T I O N S I 4. 1 4. 2 4. 3 4. 4 4. 5 4. 7 4. 8 6. 8. D I A L C O R DS T R I N G I N G ADJUSTMENTS . . . . . . 16l' 17 18 19 19 . . 4 . . 6 8 . 1 F MT u n e r 8. 2 AM Tuner 8. 3 ldleCurrent Adiustment F L I n d i c a t o r C i r. C O N N E C T I O N A G R A M N DP A R T S DI A LIST Diagram 9. 1 Schematic . [. . . ] The output circuit signal is applied to pin no. 6 (4) of the IC (TA7318P-A). The IC contains a detector circuit, compressor (40dB)' and peak hold circuit for both left and right channels. The dynamic range of the signal is thus contracted by 40dB to obtain a "peak held" DC voltage. The output power indicator segments of the FL tube are driven by the HA12010 ICs (one for each channel) equipped with 12 pairs of differential amplifiers. These amplifiers are biased at increasing levels, so each amplifier will commence to operate separately as the input level increases. And since these amplifiers apply the voltage to the out" put power indicator segments, each successive segment will light up in tum as the input level rises. 8 P R O T E C T I O NC I R C U I T In order to protect both the amplifier and the speakers, the SX-450 has been equipped with a protection circuit which is opened and closed automatically by a relay in the output circuit. 4-11, this circuit consists of 3 main component parts. F )c (fafatSP) O ET E C I O R t/2 fD I FLUORESCEN ] N D I C A I O R T Ug E a c 7. 4-9 Powerindicatorcirclrit The relay drive circuit controls relay operation, delaying relay closure when the power is switched on, opening the relay quickly when the power is tumed off, and a. lsoopening the relay in response to instructions from each detector circuit. When the power is first switched on, C4 is charged up via R8, thereby increasing the potential difference across the capacitor terminals. Once this potential difference exceeds the zener diode, Q6 is turned on due to the forward biasing, thereby closing the relay contacts. Pass it over pulley D, wind it around the tuning drum 2 times, and finally tie it to the spring hook O so that it is tensioned. Align the dial pointer with the starting point of the dial scale, and then passthe cord over it. Check that the dial pointer is in line with the starting point of the dial scale. Finally apply the locking paint to the cord securing positions (stud O and spring hook O ) and the dial pointer connection. T u n i n gd r u m D ial shaft Startingpoint \ Dial pointer D i a lp o i n t e r F i g . 7 - 1 D j a lc o r ds t r i n g i n g Y 8 . Connect the FM SG (FM signal generator) to the FM antenna 300O terminal. o The tuning coils in the FM front end does not have an adjusting core. Consequently, tracking adjustments at 90MHz are performed by regulating the gap between rotor and stator of the tuning capacitors (VC-1, VC-2, and VC-3). The expression "adjust VC (VC-1, VC-2, and VC-3) found in the text means that the two outer rotor blades of each of these tuning capacitors are to be extended outwards with spatula (Part No. 8-1. S t a t or Botor blade Spatula { G G K0 6 6 ) Stator Rotor blade 1. Set the SX-450's dial pointer to 106MHz, and the FM SG output to 106MHz, 106dB (modulation -40OHz, t7 SkHz deviation). Then tune the dial pointer to 90MHz, and set the FM SG output frequency to 90MHz. [. . . ] R 1 t 8R 1 2 1 , R 1 2 3 R'f29, R301 R304, R313 R322, R324 c c D s L 1 0 1 J5 0 c c D w K 1 5 0 K5 0 4 C K D Y B 7 1 K5 0 C K D YF 1 O 3 Z 0 5 RE S I S T O S R c201 c202 c204 c206 Whetr arderingresistors, conNert lhe resistance uolueinto codefarm, ond. os before. Symbol & D. scriprion R D 1 / 2 P SI I D D J RDl /4PM F L]LTU J R 4 1 , R 3 2 5 R4, Ft8, R49, R79, R80, Ra2-R84, R111, R122 R D 1 / 4 P ME N NJ R201 R208 SEMICONDUCTORS Symbol& Doscription SEMICONDUCTORS Symbol & Dscription 3SK73 NJrvl4558DV (!PC4558Cl rM52l4 L o1 010 o 3 0 1 , o 3 0 2 ASS-012 2SC461 B 21K261 OTHER Part No. o201 D201, D202 Symbol& Oes. ription x201 Cr 5tal resonator 31 Switch Assembly (GWS-233) Symbol & Dsscriplion ASG, 241 R D 1/ 4 P M t r N t r J 54 R343, R344 Pushswitch rl- 2SA733A Symbol & Dsscription r i ( 2 s A1 o o ) 2SC461 2SD880 ( 2 S D 3 1)3 MZ t40 twz-1401 1S1555 {'ts2076) o30 034 o10 o4 Lead Out Assembly ( A W V - o 1 1 ) cotLs Symbol & Dscription D1 D2, D7 OTHERS r24 n2A CAPACITORS L1 L4 R F c h o k ec o i l ASS{1'l A AV {O7 VAZ30PO6OF C M Svmbol & Description Symbol& DGcription X1 V1 ACM{10 C K D Y A1 O 3 K 0 5 c K D Y F 4 7 3 25 0 coMA 223K s0 c c D c H 1 0 1 J5 0 C K D Y F3 9 1K 5 0 ccDcH 020c 50 C E A3 R 3 M5 0 L C E A4 7 1 I V1 O L C E A1 0 1 M 5 L 2 C E A2 2 1 M1 6 L CEA 47OM50L cEA 22tM 25L cEA 2R2t\, 1 L 50 C E A2 2 1M 1 O L N')l?R D I / 2 P S Fn n : l J R 5 2 Pn L i L l J TCl Trimmer Crysial resonator(5. 12 MHz) F l u o r e s c e n ti n d i c a t o r t u b e ( FR E O U E N C Y ) Screw C3, C5, CA c11 , Clt -C21. C30 (AWS-149) FunctionswitchAssembly swtTcH Symbol & Description c4, c6 cl0 c9 c12 cl5 c] c'14 c29 c13 c26 c22 c16 ll-hcn orderinE rcsisfors, conL)erI the resislance rolLle into tode form. [. . . ]