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ORD ERNO.
ARP -1 19-O
FM /AM D IGITAL SYNTHESIZEDTUNER


TXr930
M O D E LT X - 9 3 0( T X - 9 3 0 L ) O M E SI N N I N E V E R S I O N S I S T I N G U I S H EA S F O L L O W S :
C D D
Model Voltage Remarks

TX.93O/KU AC120V only U . S . A .m o d e l

TX-930/HE AC22OV and 24OV (switchable) Europeancontinent model

TX-930tHEZ AC22OV and 24OY (switchable) West Germanv model

TX.930/YP AC24OV only Australiamodel

TX-930/SS A C I 1 0 V , 1 2 Q V, 2 2 O V a n d 2 4 O V ( s w i t c h a b l e ) South Africa model

TX-930/S/G A C l 10 V . 1 2 O V , 2 2 O V a n d 2 4 O Y ( s w i t c h a b t e ) U.S. military model

TX-930/S A C 1 1 0 V , 1 2 O V , 2 2 O Va n d 2 4 O V ( s w i t c h a b l e ) G e n e r a le x p o r t m o d e l

TX-930L/HE AC22OV and 24OV (switchable ) E u r o p e a nc o n t i n e n t m o d e l w i t h A M - L W b a n d t u n e r

TX.93OL/HB AC22OV and 24OV (switchablel United Kingdom model with AM-LW band tuner

o This servicemanual is applicableto the KU Wpe.
o Ce manuel d'instruction se refdre au mode de r6glage, frangais.
en
. Este manual de serviciotrata del m6todo de ajusteescrito en espafiol.


CONTENTS 7. P . C .B O A R D S O N N E C T I O N I A G R A M
C D 13
1. SPECIFICATIONS 2 8. SCHEMATIC IAGBAM
D 17
2. PACKING 2 9. ELECTRICALPARTSLIST.. ....... 20
3. F R O N T A N E LF A C I L I T I E S
P 3 10. EXPLODEDVIEW. ...23
4. P A R T SL O C A T I O I " 4 .11.
ADJUSTMENTS 24
5. B L O C KD I A G R A M 5 REGLAGE 26
6. CIRCUITDESCRIPTIONS o AJUSTE 28
1. SPEC|FICATIONS
FM Tuner Section Miscellaneous
UsableSensitivity 10.8dBf(0.9bpV) PowerRequirements AC120V,60Hz
50dB OuietingSensitivity Mono; 15.8dBf 11.7ttYl PowerConsumption l Twatts
Stereo;38dBf(229V) Dimensions 4 2 0 ( W )x 6 9 ( H ) x 2 1 9 ( D ) m m
Signal-to-Noise
Ratio Mono; 78dB (at 85dBf) 16 - 9 / 1 9 ( w )x 2 . 1 1 1 6 ( H l x 8 - 5 / 8 ( D ) i n
/
Stereo;75dB(at 85dBf) Weight(without package) . . 2.9kg (6tb 6oz)
Distortion(at 65dBf)
Furnished
Parts
Mono. ....1kH2;0.0fflo
FMT-typeAntenna ....,l
Stereo ....1kH2:O.1So/o
AM Loop Antenna l
CaptureRatio. ....1.0d8
AntennaCatcher ......1
AlternateChannelSdtactivity . ... 400kHz;SOdB
ConnectionCordwithPinPlugs
stereo
separation Operatinglnstructions
...... l
i;;il;lllff;i3:3 ........1

Frequency
Response . . . . 2OHz l5kHz 1?.30A
to
SpuriousResponseRatio. ...70d8
lmageResponse Ratio . 40dB
l F R e s p o n sR a t i o .
e . .80d8
AM Suppression Ratio . SOdB
MutingThreshold . . 19.2dBf(SpV)
Antenna Input . 3(X)ohms balanced,
7Sohms unbalanced
AM Tuner Section
Sensitivity (lHF, externalantenna) 30pV
Selectivity ....2tu8
Signal-to-NoiseRatio ..S0dB
lmageResponse Ratio . 40dB
l F R e s p o n sR a t i o .
e . .60dB
.Antenna ....Loopantenna


Audio Section
NOTE:
FM(100% MODI. 6S0mV/2.2kQ Specificationsand designsubject to possiblemodification without
AM (307o
MOD) . l90mV/2.2k0 notice.




2. PACKING
No. Part No, Description

1. ADH.OOS T-type FM antenna
2. ATB.O76 AM loop antenna
3. ADE.Os1 Connection cord
4. AAN-O47 Station card set
5. AHB.493 Operating instructions

6. AEA-O54 Loop antenna holder
7. AH4-296 Front pad
8. AHA-297 Rear pad
9. AHE.O52 Packing case
3. FRONT PANEL FACILITIES


T--E-] r--i--l r-:E--t r--E-t f-;.t t---r-r T-F--l T-;-l




O poweRswrrcH (PowERl @ MEMoRY/sroP
swrrcH
When this switch is set to the ON position,poweris supplied This is pressedonce the desiredstation has been picked up
to the tuner's main circuits. The unit's power switch is in the auto scan mode. lt is'also pressedwhen a station
gearedto selecting transformer's
the secondary and so even which has been picked up in the manual tuning mode is
at the STAND-BYposition, the unit's circuitrywill work as. presetinto a STATIONCALL switch.
long as the power cord is connectedto the power outlet.
Disconnect power cord from the power outlet when you
the swrrcHEs
@ rururruc
do not planto use the unit for a long periodof time. Theseare pushedwhen locatingstations.A station can be
locatedwith a single push in the auto scan mode. In the
@ stcrualrNDtcAToR manualscan mode, one push advances frequencyby100
the
This shows the strength of the signalspicked up from the kHz in the FM band and byl0kHz in the AM band.
broadcastingstation. A : Push to locate a station broadcasting a frequency
on
higherthan that displayed.
@ rrta rNDrcAToR
srEREo V : Push to locate a station broadcasting a frequency
on
This lightswhen a stereoprogramhasbeenpickedup during lower than that displayed.
an FM broadcast.
@ euro scANswtrcH
@ rneouENcY DTSPLAY This is usedto selectthe tuning mode: auto scanor manual
scan.
@ rurucrroNrNDrcAToRs
@ STANON NAME DISPLAY PANEL
@ AUToscAN rNDrcAToR
This lightswhen the tuner has beenset to the AUTO SCAN
Pull this out from the front at the top. After the station has mode.
been preset into the STATION CALL switch, remove the
corresponding card from the accessory
slide it into position.
"station card" and @ srenoN cALLswtrcHEs
Theseare used to preset broadcastingstations. Eachswitch
O rurucroN
swrrcHEs from "A" to "H" can be usedto presetone FM stationand
one AM station.
These are used to select the FM and AM broadcasting
bands. @ srafloN tNDtcAToRs
These indicatorslight in successionwhen a station has been
@ rru MUTTNG
swrrcH picked up in the auto scan mode or when the MEMORY/
ON: The mutingcircuitis actuated duringFM station tun-
ing to suppressthe irritatinginter-stationnoiseand STOPswitch is pressed while a station is being tuned in.
make the tuning operationmore pleasant. The positionof the STATIONCALL switch which has been
pressedis indicatedduring presettuning.
O F F( M O N O I :
This positionis set when the desiredstation cannot
be pickedup satisfactorily the ON position.In this
at
case,even a stereoprogramwill be heardin mono.




J
4. PARTS LOCATION
NO?ES:
. Memory backup battery o The I marh found on some component parts indicates the importance of the
on the battery assembly safety factor of the part. Therefore, uthen replacing, be sure to use parts of identical
designation.
Ni-Cd Lithium
o For your Parts Stoch Control, the fast mouing items are indicated with the marhs


Qn q- ** and *.
*i GENERALLY MOVES I'AS?ER THAN *.
This classification shall be adjusted by each distributor because it depends on model
number, temperature, humidity, etc.
o Either of batteries (Ni-Cd or Lithium) is used to the memory backup in the KU
type.
Front Panel
View
Top cover
ANE-393

Knob (FM, AM)
Knob (POWER) AAD-481
AAD417

Knob (FM MUTING) Front cover
AAD-482 ANM-209

Front View with PanelRemoved
* LED numeric display
AEL-395

* L E D ( R e d ,S T E R E O ) L E D ( G r e e n ,F M , A M , A U T O S C A N )
AEL-372 AEL-383

LED (Green, IGNALI
S
AEL.371
Front base assembly
ANR-515

** P u s hs w i t c h ( P O W E R , F M M U T I N G ) L E D ( R e d ,S T A T I O N }
ASG-540 AEL-372

Top View
I Carbon composition
resistor 2.2Mo.,1%W
ACN-029
Tuner assembly
Lithium battery AWM439
AEX.OO8
(Ni-Cdbattery)
( A E X - 0 11 )


Power transformer
ATT.916


RearPanelView
** Slide switch
(FM DE-EMPHASIS) ** Slide switch
ASH-015 (AM CHANNEL STEP)
ASH-015
Terminal (ANTENNA)
AKA.O17 Strain reliel
AEC-327

1\ AC power cord
ADG.O52

Terminal
Terminal (OUTPUT) ( A U T OF U N C T I O N }
AKB.O77 AKN-034



4
5. BLOCK DIAGRAM

F M T UNER MPX STEREODECODER

ANTENNA
RF AMP. MIXER IF AMP. 8
DETECTOR IC
ll AF AMP.
MF'( STEREO OECODR




ffil5
FMr
300rl
MUTE VCO
F IN KILLER
Fl I
75rl 4 9 85 t2 rOrS 1915
GND L coltr+B
FM+8
coM+B




COM+B AM+B




LOOP
A
A M TUNER SYNTHESIZER CIRCUIT

| sllrHEsrzERrc I
tr ".. STATION
5 FMrN anzffi rc YO
AM tN RESET 12 Yt
M54922P f,ff g Y2
n___
EEf' DArA rN
7 MtX.OUT
PO AB CD
e rF rN t4 1234
?'r.I.,,,

81 DET. . I N D +B
OATA IN Y7 9
njo$' 9yJ' [-E n;'

CHAiilEL
STEP
- LED NUIIRIC DISPLAY
|ND+B
s*x,
e
C ONTROL CIRCUIT
lorxz
FUNCTIOil
FMC


AMd
STATION
CALL
30 Ra Rz(CPS) 29
sC
Re(RESETI28
3l Rs Oo f3
zl
Or {4
32 Rro Oz 15 POWER SUPPLY CIRCUIT
e{
OE 16

s{ 33Rrt SO 5
Rs(SCAI lNOl 25

el 38 Ko Rtr (A.STOP)

I NO + B
Kt Pt
sC
P060044
Kz Rtz(St{ MUTE} I N D +B
zl
Exr. x'TAut Soorxz IND+B
r{ ;
Rs (O/51

MEMOR/
zsroe {
T U NIN G
oowr.r {


UPq
AC{20v
AUTO l# 60Hz
scAN 1r- I




5
Ei. CIRCUIT DESCRIPTIONS
FM Front-End Multiplex Decoder
The FM front-end uses a J-FET RF amplifier This section consists of IC (PA4006-A), and
(single stage), and variable capacitance diodes the contains the PLL system switching signal generator
equivalent of a 3-ganged tuning capacitor. The circuit, chopper type MPX decoder, pilot signal
local oscillator uses an output buffer amp to automatic canceller, stereo auto selector, VCO
maintain stability during strong signal reception. killer circuit, muting amplifier, muting control
The local oscillator signal is input into the syn- circuit, and stereo reception indicator circuit.
thesizer circuit and compared with the reference The choppdr type switching circuit either does
signal, and the resulting tuning voltage is applied or does not establish a signal, thereby generating
to the variable capacitance diodes where it be- no noise or distortion.
comes the oscillator frequency (or tuning frequen-
cy). AM Tuner
The AM tuner section uses IC (LAL247) and
r Pulse-Swallow PLL Synthesizer
variable capacitance diodes the equivalent of a
When the VCO (Voltage Controlled Oscillator) 2-gange tuning capacitor.
d
frequency is very high and the CMOS programm- The local oscillator signal is input into the syn-
able divider operating frequency is exceeded, the thesizer circuit and compared with the reference
PLL will cease to function. Two methods are signal. The resulting tuning voltage is applied to
presently available to resolve this problem. In one the variable capacitance diodes where it becomes
of these methods (the fixed divider system), an the oscillator frequency (tuning frequency).
ECL (Emitter to Emitter Coupled Logic) prescaler The AM tuner of TX-930L is a two wave-band
is positioned in front of the programmable divider. tuner with MW (medium wave) and LW (long
And when, for example, a 1/10 prescaler is em- wave).
ployed to obtain 251 reference frequency will be 2.5kHz. This frequency
is very low and cannot be adequately removed by
the low-pass filter. As a result, signal components
are leaked into the mixer leading to deterioration
in the S/N ratio. This is one of the main disadvan-
tages of the fixed divider system.
The other method available is the pulse-swallow
system which employs a special frequency divider
called a "two-modulus prescaler,, instead of the
prescaler used in the fixed divider system. In this
method, a 25kHz step synthesizer will generate a
25kIIz reference frequency and a b0kHz step
synthesizer will generate a b0kHz reference fre- L P.F.
quency, resulting in a much higher S/N ratio than f
in the fixed prescaler system. F i g .6 - 1 Pulse wallow ystem
s s
The pulse-swallow system employed in the
TX-930 is incorporated in an IC (M54922p)
controlled by microcomputer. Control Section
The TX-930 (and TX-930L) tuner is equipped
FM lF Amplifier and Detector with a microcomputer (PD6004A) which makes
The IF stage is composed of two dual element tuner operations easier. The PDG004A is a 4-bit
ceramic filters, one transistor and IF system IC microcomputer designed for synthesized tuner/
(PA3001-A) (consisting of an IF limiter amplifier, receiver control purposes. In the TX-980, this
quadrature detector, and meter drive). multi-function microcomputer is used in the
quartz PLL synthesizer and tuned frequency dis-
play control circuitry. The PD6004A pin des-
cription is outlined in Fig. 6-3. Note that the
TX-930/SS usesPD6004B.
The TX-930L is basically the same as the TX- PD6OO4A
930, but includes two bands (medium and long
Pin
wave) in the AM tuner section (medium wave Symbol Description
band). The reception band is changedby switching No.

the tuning circuit electronically in a switching Extal Clock pulse input (500kHz)
circuit containing FETs and diodes. 2 Xtal Oscillatoroutput (open)

PD6004A Input Key Matrix Description 3 R E S E T Reset input (effective lowl

Operation instructions are applied to PD6004A 4 lRo Inhibit mode control 1

by selective input of key scan clock pulses (outputs 5 SO Frequency display data output
from P0 - Pg) to the key input pins (K0 - KB and 6 SI ( g r o u n d)
R8 - R11). The PD6004A input key matrix is -sc/Td
7 (open )
shown in Fig. 6-2. (ground)
I TC
9 PO cKl Data transfer
10 P1 cK2 clock output
1 1 P2
Key s : a n c l o c k o u t p u t
9k,/ tok ( PHONO) MI (UPVI 1 2 P3

9k/tk
G.


Go
(AUX' u2 ( DNV' Ejl 13
14
oo
ol
A

B S T A T I O N i n d i c a t o r sd a t a o u t o u t
KI A/M M3 AMU 1 5 02 c (4-bit BCD codel
Gc 1 6 o3
(Pr.) D

NA
STH fl M4 (VOM)

G.
1 7 o4
Bl f+ FM M5 UPF
t 8 o5 VCA control data outout
G.
B2 f+ MW M6 ONF 1 9 o6
G. 20 07

E=A
L/M It7
21 VSS (ground)
G.
E2 CLK MA sx/Tx 22 RO VCA control data output
23 R 1 VCA indicator output
Fig.6-2 Inputkeymatrixof PD6004A 24 R2 VCA memory indicator output
25 R 3 Audio mute indicator output

9k/10k (P0 -' K3) : AM-MW tuning frequency 26 R4 Scan indicator output
step switching 27 R 5 FM s-th digit control output (0/5), LW indi. out
AM-MW tuning frequency is changed in gkHz 28 R6 RESET
I
steps when P0 is connected to K3, and in 10kHz Data transferclock output
29 R7 *t-
steps when open. In the KU, S and S/G types, this 30 R8 A
selection can be made by the AM CHANNEL STEP Synthesizer
3 1 R9 B Key
switch located on the rear panel. In the HE, HB, control
HEZ, SS and YP types, the frequency step is fixed 32 R 1 0 c input
data output
at 9kHz. 33 R 1 1 D
34 R12 Muting output
35 R l 3 Scan stop input
36 R14 (groundl

37 STBY Inhibit mode control 2
38 KO
39 K 1
K U , S , S / GT Y P E S -+B Key input
HE,H8,HEZ,SS,YP
rYFES
40 K2
41 K3

Fig. 64 AM-MWchannelstepselection 42 V D D *5V power source


F i g . 6 - 3 P i n d e s c r i p t i oo f P D 6 0 0 4 A
n
9k/1k (P0 - K2) : AM-LW tuning frequency step AMU (PB - K1) : T input for binary F.F.
switching Although originally designed for audio mutirg
AM-LW tuning frequency is changed in 9kHz purposes, this link is used as the latching circuit for
steps when P0 is connected to K2, artd in lkHz the non-lock type switch in the TX-930 AUTO
steps when left open. This only applies to the TX- SCAN switching mechanism. When the front panel
930L (with LW tuner), the frequency step being AUTO SCAN button is pressed,the level at pin 25
fixed at 9kHz steps. Long wave tuning frequencies (R3) of PD6004A is inverted each time Q11 is
are determined by (9N + 2) linteger number from 17 to 31. replaced by a transistor (Q12) which is controlled
by the output from pin 25. Note that the AMU
key is not used in the TX-930L, and that pin 25 of
PD6004A is kept at high level.
AA{ (P0 - Kl) : T\rning mode switching
This link is left open for manual tuning mode
setting.


Fig.6-5 AM-LWchannel selection
step

81 (P0 - R11) and 82 (P0 - R10) : FM-IF offset AMU
switching
10.700MH2 when both links are open. In the SS
type, however, both links are connected (operation
by lower heterodyne).
El (P0 - Rg) and E2 (P0 - R8) : Switching for
different regions
The El link is connected in the KU type, Fig. 6-7 Tuning mode selection TX-930
of
the E2 link in the S, S/G HE, HB, YP and HEZ
types, and both E1 and E2 in the SS type.
SX/TX (PB + R8) : Microcomputer function re-
striction
When left open, PD6004A is limited to tuner
operations. In addition to disabling the UPV, DNV, FM MUTING
(AUTO SCAN}
and VOM keys, the VCA display (outputs from
04 - 07 and R4) is disregarded.

Fig. 68 Tuning mode selection TX-930L
of




( Po-R! )
o27 oza ( Po-Re )
(Fo-Re) ( Po-R6l
( Po-Rpl
(FMlOOkHzSTEP) ( FMSOTHZ
STEP)
( Po-Ril)

( FM5OKHZ
STEP)
HEZ TYPES
s,s/G,HE,HB,YP, (LOWER SIDE SUPERHETERODYNE}



F i g .6 - 6 F M c h a n n es t e ps e l e c t i o n
l
STH (P0 - K0) : Short time hold search tuning The output level at pin 16 of. M54922P is a low
switch level during FM mode. Q24 is thus tumed on, re-
Input key for AUTO SCAN tuning mode (see sulting in FM + B being supplied to the tuner
note 1). This key has priority over the A/M key. section to start FM tuner operation.
When the front panel AUTO SCAN button is The data signal passed from PD6004A to
pressed in the TX-930, QLl (AMU key) is turned TD6301P (note 2) is 16-bit binary code serial data.
on, resulting in inversion of the level (high/low) at This is converted to 4-bit x 4 parallel data by
pin 25 of PD6004A. Q12 is turned on when pin data transfer clocks (CK1 and CK2) in TD6301P,
25 is at high level, thereby switching'the tuning and then to 7-segment decimal data to drive the
mode to AUTO SCAN. LED numeric display (the four most significant
In the TX-930L, pin 25 of PD6004A is kept at digits). The fifth digit (least significant digit) is the
high level (since AMU key is not used). The AUTO 10kHz unit column where only 0 or 5 is displayed
SCAN switch is not independent, but also servesas (the frequency being changed in 50kHz steps in the
the FM MUTING switch (see Fig. 6-8). When the HE, HB, HEZ, SlG, S and SS types). This display
FM MUTING switch is ON, Q306 is turned off and is controlled by output data from prn 27 of
Q12 (STH key) is turned on. (Since the mutirg PD6004A(H:0andL:5).
signal level is low, Q306 is not turned on by this
action). When the FM MUTING switch is OFF,
Q306 is turned on and Q12 (STH key) is turned
off. RESET


FM (P1 * R11) : FM mode switch cPs

When the front panel FM button is pressed,
OA
PD6004A passes data signals to the PLL synthe-
sizer IC (M54922P) and numeric display driver IC D8
(TD6301AP). The signal composition of the signal
passed from PD6004A to M54922P is outlined in Oc

Fig. 6-9. After the RESET input is changedto low
level, M54922P reads 4 x 5 bit data by synchro-
nizing with the CPS input. The first four pieces of
data are used in setting the frequency division of
the programmable divider, and the fifth piece of Fig. 6-9 Synthesizer
control data
data sets the operation mode.




atn
FM
(Pr-Ril,

AM
(R-Ro)




F i g .6 - 1 0 F M , A M f u n c t i o ns e l e c t i o n
MW (P1 - R10) : AM mode switching M1-M8 (P2-+K3-K0 and R11-R8) : Frequency
When the front panel AM button is pressed, preset switches
PD6004A passes a data signal to M54922P and When one of the front panel STATION CALL
TD6301P (note 2). Pin 16 of M54922P is changed buttons 1 to 8 is pressed, the corresponding
to high level during AM mode, resulting Q24 memory address is specified for read out of the
being turned off and Q23 being turned on. AM + frequency data stored in that memory. At the same
B is thus supplied to the tuning section to start AM time, PD6004A passes display data (4-bit BCD
tuner operation. Since FM + B is not supplied, Q16 code) to M74LS42P for lighting of the STATION
is turned off, and the fifth digit and decimal point indicator corresponding to the specified memory.
in the LED numeric display are turned off. If the specified memory is blank, the current tuned
frequency is maintained (without any other further
L/M (P1 - R9) : AM band switching
operation).
This input key is used only in the TX-930L. And if the memory is in memory write enabled
Each time the front panel AM BAND button is status, the currently tuned frequency is stored in
pressed and Q305 tumed on (P1 -+ R11), the the specified memory.
tuning band in AM mode is switched (medium
wave and long wave bands). Pin 27 of PD6004A is UPF, DNF (P3 - R11, P3 - R10) : Ttrning switches
at low level for LW, and at high level for MW. When the front panel TUNING UP or DOWN
AM + B (the power supplied during AM mode) button is pressed during MANUAL tuning mode,
serves as the power supply for the LW and MW the tuning frequency is increased or decreased by
indicators. Since Q303 and Q304 are both off one step (50kHz or 100kHz steps during FM mode
when LW is selected, the LW indicator lights up. and 9kHz or 10kHz steps during AM mode). If the
Q303 and Q304 are both on when MW is selected, button remains depressed, the frequency is chang-
resulting in the MW indicator lighting up. ed continuously, stopping when the button is
The tuning circuit in the AM tuner section is released again. Frequency scanning stops auto-
switched electronically by a switching circuit matically when either end of the tuning band is
containing FETs and diodes. reached.
When the UP or DOWN button is pressed during
AUTO SCAN tuning mode, the tuning frequency
starts to scan in the specified direction. If the end
of the band is reached, the scanning operation
TO
NUMERrc pauses for about 0.5 second, and then resumesin
DISPLAY
DRIVERIC the same direction starting from the other end
(TD630tP)
of the band.
o305 If pin 35 (R13) of PD6004A is changedto high
t/M
( Pr+Re) Rp Lw
9112uw+e level during AUTO SCAN mode, the scanning
operation is stopped, and memory write enabled
AM
BAT,D
status is set for five seconds. (The STATION
indicators flash on and off furing this period).
If a memory addressis specified by pressing one of
SYNTHESIZER
the STATION CALL buttons during this period,
rc (M54922P) the frequency at that time is stored in the memory,
AM TUNER SCTION and the frequency scanning is then resumed. If
TUNER t c
AM 247 | nothing is done during the five-second scanning
ANTENNA
TERMINAL
pause, scanning is resumed automatically at the
end of the five-second period. The signal applied
to pin 35 of PD6004A is the result of level inver-
sion of the FM MUTING signal during FM mode,
and makes use of the AM SIGNAL STRENGTH
meter drive signal during AM mode. The tuned
frequency is detected by these signals being chang-
ed to high level.
0304


F i g .6 - 1 1 M W / L Wb a n ds e l e c t i o f o r T X - 9 3 0 1
n




10
M74LS42P
STATIONCALL
I
(P?- K3)
Oo
2 Ot
(P2+K2) O2 YI



(P2+Kt) 7Z
4
(P2+Ko)

Po
TO NUMERICDISPLAY
(P2+Rri ) E
PI DRIVERIC
6 (TD630iP)
(P2-Rrc) E

( P2+R9) Y'
I
(P2+R!) ii


TO PLL SYNT}IESIZERIC(M54922P}


F i g . 6 - 1 2 P r e s eo f b r o a d c a s t i n g a t i o n s
t st




UEUORYa
( P3+Re) '




TUNING F i g . 6 - 1 4 M e m o r yk e y
UP
( PJ*Rir) ra
DRIVERIC
DOWN
so
* B.L2 (pin 34 of PD6004A)
( P3-R|o)
Pin 34 PD6004A is switched to low level for
about one second when the FM, MW, or L/M key
is switched on. And when M1 - M8, UPF, or DNF
is switched on, the pin is switched to low level for
about 0.7 second. This serves as the muting signal
used in eliminating switching noise following level
TO PLL SYNTHESIZER
1M54922P''
IC inversion. The pin 34 output also serves as the
automatic switching signal applied to the amplifier
F i g . 6 - 1 3 T u n i n gc o n t r o lk e y s component equipped with an automatic function
selector feature.



MEE/STP (PB - R9) : Memory write switch
When the front panel MEMORY button is
IO MUTING GATE
pressed, memory write enabled status is set for
about five seconds.During this five-secondperiod,
STATION indicators 1 to 8 flash on and off -wn
AuToFUNCTtOta
r- TRIGGER
OIJTPUT
until some other relevant key is operated, or until fn
the five-second period is completed. This key also
seryes as the frequency scanning stop switch. F i g .6 - 1 5 S w i t c h i n g u t e / a u t o u n c t i o nt r i g g e r
m f
NOTE 1:
The TX-930 AUTO SCAN switch starts the scanning of PD6OO4A
tuning frequencies when the TUNING UP or DOWN
tRo
button is pressed. If a broadcasting station is tuned
during this scanning, the scanning is stopped for about
fiue seconds. Presetting of the tuned frequency is enabled
during this fiue-second period (the STATION indicators
STBY
flash on and off indicating that presetting is possible),
and if any of the STATION CALL buttons from I to 8
is pressed, the tuned frequency is stored. in the memory
corresponding to the pressed button, and the scanning FE5E?
operation is subsequently resumed. If no buttons are
pressed, the scanning resumes after a wait of five seconds.
NOTE 2:
The TX-930L uses TD6301AP which differs from TD
6301P in that the displayed band edge is 153hHz during
LW reception. (The corresponding frequency ind.icated
by TD6301P is 155kHz).

M icrocomputer Operation Control
The TX-930 POWER switch is connected to
the secondary coil of the power supply trans-
former. When the POWER switch is switched off
(STANDBY position), power is still supplied to F i g . 6 - 1 6 M i c r o c o m p u t e ra c k - u p o w e rs u p p l y
b p
the microcomputer (PD6004A) so as to maintain
the microcomputer memory functions. And even
if the AC mains power is disconnectcd complete-
ly, the memories are still preserved by a built-in
lithium (Ni-Cd) battery (note 3).
The levels of the IRQ and STBY pins in
PD6004A are set to low level when the POWER
switch is in the STANDBY position. In this
condition, PD6004A can suspend all operations
and stop the clock pulse signals applied to E. Xtal
pin. PD6004A can thus preserve the memory
contents with a consumption current of less than
10pA (2.5V min).
When the power is switched on again, a nega-
tive pulse is applied to the RESET pin to restart
PD6004A functions. The RESET signal is generat-
ed by utilizing the rising edge of the IRQ signal. Fig.6-17 for
Powersupplysequence stop/restart
The power supply sequence for stop/restart in
outlined in Fig. 6-17.
NOTE3:
Either of batteries (Ni-Cd or Lithium) is used to the
rnemory backup in the KU type.
2 3
7. P.C. BOARDS CONNECTION DIAGRAM



A
TUNER
Ass' y AW M- 439

F5
VR2 F6



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4 5 6
NOTE:
The microcomputer LSI (PD6004A) hre been desiged to
match different versions (KU, S and S/G types) by combi-
nation of the diodes (D25-D28) connected between pin
no. 9 and nos. 30-33.
. In the KU type, remoue the diodes (D25, D26, D28).
. In the S and S/G types, remoue the diodes (D25, D26,
D27).



CONTROL
Ass'y
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odes (D25, D26,




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10 11 12
Appearance Transistors lCs
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8. SCHEMATIC DIAGRAM

T U N E RA s s ' y AWV-439
O r'!, 3 FM FRONI LNO




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