Radio Shack Realistic PRO-34 User manual

,.
canner
PRO-34
Pro ramma Ie
atalo
er:
© 1988 , Tandy Corporatlon.
All Rights Reserved .
RealIstic and Radio shack are reglstered trademarks of Tandy Corporatlon .

CONTENTS
Page
contente- .. ··· · · · · .. ············· · .. · · · · ..
Specifications·· · · · · .. .o· · ·· .. ·· · • · · ·· · ·· · ·· · · ..
2
3
Bloek Diagram······ .
....... .... .... .. .. .. .. .... .. . .. .. .. .. .. .. .. .. .... ......
4
Principles of Operation· .o 0 0 .o .o.o .o .. 5
General Operation Outline· .... ································ ··································· ······ ········ ········ ··················· 7
Alignment/Adjustment········································· ·· ········· ·· · ·· ······· ·· ·· ······· ·· ·· ·· ·· ····················· ·· ····· ·· ·· ·
Reception Check··
·· ····· ·· ··········· ·· · ···· ········ ·· · ·· ········· ·· ··· ·· ···· ···· ··········································· ·· ········ ··..
Memory Check···· ·· ······················ ·· · ·· .
Troubleshooting·····
·· ········································································································ .
Wiring Diagram·············· .
Jack PCB (Top View)'·' .
Jack PCB (Bottom View)·· ·· ·· ···· ·· ·· ····· ·· · ·· ················· ·· · ·· ··· ·· · ·· ·· ········ ·· ···· ·· ···························· ·· ·········
Linear PCB (Top View) ········ ·· · ·· ··· ·· ····· ·· ··· ·· ··················· .
Linear PCB (Bottom View)···························································· ·· ······· ·· ······································
Logic PCB (Top View) ················································· .
Logic PCB (Bottom View) ············· ·· ·· ······················ .
Electrical Pa rts List······ '. ' .
Mechanical Parts List·· .
Disassembly Dlagram/Exploded View·········· ······· ······· ······ ······· ··········· ················· ········ ············· ····· ·....
Semiconductor Lead Identlficatlon and IC Circuit Diagram..· ······ .
9
16
17
18
20
21
22
23
25
27
29
31
44
45
46
Microprocessor (IC1) Port Format······
·· ······························ ·· ········· ·· ················································· 54
Appendix' .55
Schematic Diagram
(Linear Section)··················· ·· ················· ······ ·· . 56
Schematic Diagram (Logic Section)··· ·· ······ ·· ························· ·· ······ .
2
58

SPECIFICA TIONS
NOMINAL
1.0
2.0
1.0
1.0
2.0
1
25
+10
± 20
50
50
50
*1 30 -54 MH z 5 kHz steps
108- 136 MHz
25 kHz steps
136.00 5 -174 MHz
5 kHz steps
380-5 12 MHz
12.5 kHz ste ps
806.00 00 -823.93 75 MHz
851.11 25
-868.93 75 MHz
896.11 25
-960.00 00 MH z
12.5 kHz steps
LI MIT
2.0
5.0
3.0
4.0
4.0
2
15
+14
+25
40
40
40
Not spec if ied
UNIT
/l V
/l V
/l V
/l V
/l V
/l V
dB
kHz
kH z
dB
dB
dB
VHF HIGH
VHF LOW
AIRCRAFT
UH F HIGH
UHF LOW
VHF LOW FM
AIRCRAFT AM
VHF HI GH FM
UHF LO W FM
UHF HIGH FM
at threshold
at tlght
-6 dB
- 50 dB
VHF LOW at 40 MHz
AIRCRAFT at
124 MHz
VHF HIGH at 154 MHz
UHF
6 8- 88 MHz for 20 -9134
806- 960 MHz for 2 0-9 134
Spurious Re ject ion
(except primary imag
e)
Squelch Sensit ivity
Selectiv ity
Sensit ivity
Frequency Coverage
40
+ 5
30
25
30
25
25
5
6- 10
1 -3
150
dB 50
kHz + 8
dB 45
dB 35
dB 45
dB 35
dB 35
mV 3
channel s/ sec 8
sec 2
T.H.D.10% mW
200
Any 200 channels in any band co mb ination
Li quid crystal display
Direct
Key en try Digital-Controlled Synthesizer. Superheterodyne
1
st IF : 10.7 MHz 2nd I F: 455 kHz
9V DC negative ground only
6
AA batteries or a su it ab le adapter
Antenna. Earphone. External
Po wer an d Charge
(EI ARS-2 04-A )
VHF LOW at 40 MHz
AIRCRAFT at
124 MHz
VHF HIGH at 154 MHz
UHF LOW at
450 MHz
UHF HIGH at 860 MHz
Vo l. Min.
Jacks
Power Source
Residual
No ise
Scanning Speed
Scan Delay Time
Audio Output Power
Channe
ls of Operation
Channel, Frequency
an d Mode Display
Receiving System
IF Rejection
Modulation Acceptance
Signal
to Noise Ratio
Note :Nominal Specs represent the design specs: all units should be ab le to approximate these- same will
exceed and some may drop slightly below these specs.
Li mi t Specs represent the absolute worst condition
that still might be considered acceptabl
e: in no case should a unit perform to less than any lim it spec.
- 3-

PRINCIPLES OF OPERATION
The PRO -34 is a PLL (Phase Locked Loop) syntheslzed VHF /UHF FM receiver, controll ed by a CPU
(centraI processing unit) via a keyboard.
The V
HF Lo band (30 "'-'54 MHz) or VHF Hi band (136.005 "'-'174 MHz) is received in 5 kHz increments
and the U HF . Lo band (380 "'-'5 12 MHz) or UHF Hi band (806 "'-'960 MHz) is set up to be 12.5 kHz
increm
en ts.. Similarly, the alrcra ft band (108 "'-'136 MHz) is in a 25 kHz step.
All functions such as receivlng frequency range,frequency determination,scanning and delay time etc.
are con
tr olled by the CPU. The CPU is able to do only the assigned tunetlens. and no modl ficat ion of the
CPU is feasible.
The following paragraphs
ex plain the ope rat ion of the circuit in ter ms of the functional blocks:
•
Avaractor (variabie capac it ance diode) tuning ("A utomatic Tuning System") is employed on all Bands.
Fie
ld-eff ect transistors (FET) are used in the RF/MIX circuits of low and high Bands, to achieve optim um
mix-modulation and rnutual-rnodulatlon characteristics. 0109 amplifies the 10 .7 MHz IF. A 10.7 MH z
mon olithiccrystal filter is incorporated to ob ta in a good IF selectivity.
IC1 01 contains thelocaloscilla tor ,mixer, IF amplifier, quadrature FM detect or and noise amplifier. A
crystal oscillator produces 10.
245 MHz whlch is mix ed with 10.7 MHz, resul ti ng In 455 kHz IF. A 45 5
kHz ceramic filter Is provided to increase the IF sele ctiv ity .The 455 k Hz IF signal is amplifled in the IF
amp stage. and the qu adrature FM detector detects It to an audio signa !.
The detected output of the FM Is applied to IC9. IC9 ampllfles the au di oslgnals and drives the speake r.
•
IC1 is the CPU .The CPU does data processing, calculation etc. Any unstable supply voltage (VDD) to the
CPU can cause the CPU to get mal-functloned, such as wrong data processing, wrong data transfer etc.
Ta overcome this, C2 and
R1 3 in the logic circu it "initia li ze" the CP U. (R efer to the loglc section
schematic
on page 60 .)
The lnlt
tall zatlon Is done as soon as b atte ries or external power is connected. Flgure A shows the
inltlalizing wavefo
rm. Memory ba ck up function Is automatlcally start ed whene ve rthe ini tl allzation has been
done
and then tune tl ens In approxl ma tely 1 hour aft er thebatteries or extern al power is dl sconnect ed .
The
RESE T switch is located in the hole on the bottom of the ba tte ry compartment and is us ed to
correct
an LCD or keyboard mal-function.
The unit has battery-saving control circuit in manual mode. When the unit is in operation,the pin 74 of
IC1 (C PU) is "H" and 03 is ON. If no signaI input or no key input exlsted more than 5seconds in ma nual
mode with the SO UELCH on, the pin 74 becomes "L" (Fig. B) and 03 turns off then the power supply for
most
of circ uit is shut down (except CP U and Audio circuit). In this ba tt er y-s aving mo de, 40% of the
power can be
sa ve d during normal operation.
The initialization
of the CPU ,mentioned above can also be done by pushing RESET switc h. Figure A
sh ows the rise time duration wh en the inltiallzation is done.
CX 1 (2 MHz) is a ceramic oscillator clock which is used for CPU control. Figure Cshows 1/8 divided
waveform
of Figure D.
- 5-

IC 1Pin CD
VOD
- - --
---
--- ----
Voo/2
--- ---
I
I
I
II
1+320~
.I mSlc I
I
Figure A
IC 1
Pin ®
Figure B
0.5 sec
I sec
•
5 sec
-
-- - ---
-
-- -- - - -
--
H
L
Pin 74
Figure C
•
"-- -
I
I1
I- 4usec I
I.. I
o
4.4V
IC 1Pin@
: IC I Voo :4.4V
I
---
-1
/\
,
1--- -Y
V V V
IVVVV
I
VVVVVV
II
I·
4usec
,I
..
4.2V
0.2V
IC 1Pin@
Figure D
- 6-
•

*1 *2
En ter the desired frequency in each channel as Enter search frequency as follows.
follows:
.i
i.
Enter the deslred frequency with numeral Press ILIMIT Iand enter the lower frequency
of
keys. the range
to search with numeralkeys,
i,
•
Press 1 ENTE R1 te memerlze the frequency. Press IENTER
I.
If wrong frequency (out of the band) is enter-
ed, "ERROR" wlll be displayed. •1•
Press ICLEAR I. then enter the corre ct fre-Press ILIMIT 1and enter the upper frequency
quency. of the range
to search.
•,
Pr ess IPGM Ito advance to next channel. Press 1ENT
ER I.
Enter thefrequency and press IENTER I.
.i
Repeat It to mem orlze frequencles one by one.
iPress IAI
to search from lower frequency.
Press ITIto search from upper frequency
Press I
PRI I 50 that prlorlty channel appears. (squelch must be on).
•
Ta revert to the prevlous channel, press Press I
MON Ito st ore the des lr ed frequen cy
I PRI la galn.
(1 0monitor channels) In the search mode.
••
Press numeral keys '(1 through 200)
and then Ta
start search, press IAI or IT I.
press [EffiJ.
Prlorltychannel wlll be changed
to newly
entered channel.
Ta call monitor c
ha nnels, press I MO N I.
•
1
Press IMON Isa
that
next monitor channel
appears.
Ta call the monitor channels directly, press
numeral keys.
i
Ta revert
to the prevlous channel, press
I PGM I·
•
•
KEY LOCK switch ON. All keys unoperate
except
REM OTE KEY (SCAN, MAN).
•
- 8-
•

A LIGNMENT / ADJUSTMENT
Alignment and Test Point Locations
Logic PCB
TCI
~
~
14
IC 3
Linear PCB
D
T109'
D
T II O°
TPI0 4
T 111
D
D
rtoa
TP I05
°
ffi] L1 14
Ir'I0TPI06
&lTC 103
TI02
D
°
TPI OI T105
TPg 3 D
TI 03
@) Tl I2 T106 T104
TCI 05
@) @)
TCI04 ° @) TC101
TPI02 TC102
@)TC106
,..
D
TlOI
Alignment Preparation
Test equipment required
1. Oscilloscope (0 "-'500 kHz, 0 "-'50 MHz)
2. AC SSVM
3. DC SSVM
4. Frequency Counter
(200 MHz)
5. 8-
ohm dummy load
6. Slow Sweep Generator with variabie marker
(10.7 MHz)
7.
VHF Sweep Generator wlth variabie ma rker
(30"-'54 MHz, 136.005"-'174 MHz)
8. UHF Sweep Generator wlth variabie
ma rker
(380
"-'512 MHz)
9.
FM Signal Genera tor
(30 "-'54 MHz , 136 .005 "-'1 74 MHz, 380 "-'512 MHz,
806 "-'960 MHz)
Channel Frequency(MHz) Channel Frequency(MHz)
1 30.0 000
9
174.000 0
241
.0050 10
380 .0 00 0
354.0000 11
451.0 00 0
4
108.0000 12 512 .0 00 0
51
21.0000 13 806.0 00 0
6
136 .0000 14 860.0 00 0
7
136. 0 050 15 960.0 00 0
81
55 . 0000
Table 1
Notes:
• Use non-metallic tuning tools.
• The test equipment and receiver should be warm
ed up at least 10 minutes before proceeding to
allgnment.
• The slgnal level from the generat
or sh ould be kept as low as posslble to obtaln the usabie output.
. 6 AA batterles are required
to hold the mem ory when the external power Is disconnected.Always be
sure the batteries are fresh. If the low- b
atter y indic at or lights, reptace the batterles, or the
pre-programmed ch
an nel memories will be lo st land wlll have to be re-programmed).
The memory backup cir
cuit can hold the programmed chann el memories for about one hour ev en when
neither the batteries nor the external power is pr
ov ided.
Program
CH1 to CH15 as follows.
'.
~ 9 -

ALIGNMENT PROCEDURES
Reference Frequency ose Alignment
Step ContraISetting Test InstrumentAdjust Remarks
Connection
OFF / VOLUME Contro l:
Connect Frequency counter TC1 Adjust TC1 sa that the f
re -
ON to TP105 thraugh a ceramic •
11 8.7 0000 0 MH z
•quencyIS
1
SQ UE LC HControl: capacitor
(5- 10 pF) and ± 10
Hz .
Fully counterclockwise
GND .
(CCW) Figure 1
Select Channel 4.
IF Section Alignment
Step Contral Setting Test Instrument Adjust
Re marks
Connection
OFF / VOLUME contral: Connect
test instruments as T10 7Adjust
T107 to sy mmetrize
ON
•shown
in Fig. 2 T10 8the upper and lower heights of
•
2
SQU E LCH Contral: CCW the Scurve
to be equal and
adlust T108 to symmetrize the
left and the right of the S
••curve.
Note:
Du ring alignment. maintain the sweep generator output at thelowest level possible to prevent overload-
•
Ing.
Figure 1 Figure 2
•
10 1
Un it T
P1 03
Scope
U
nd er Te st
,l,.
',j,.
~
••
-,
10 .7 MH z
-<>v
H
.01 i:J F
Sw eep Gen er ato rI.l.
,j.
TP
5 - 10pF
TP125 .1
Unit -"Frequ
enc y
Under T
est
f
Cou nt er
'"
veo Alignment
VHF LO Band
Step Control Setting Test Instrument Adlu
st
Remarks
Connection
•
OFF / VOLUME Control. Connect
DC SSVM to
T C103
1)
Sel ect channel 3 and ad-
ON
TP106 and GND.
T1 11 •just
TC103 for 13V on
SQU E LCH Contral: CCW the
DC SSVM.
Sele
ct channel 1throu
gh
2) Select channel 1
an d ad-
33. lust T11 1
for 1.0 V
on
the DC SS VM .
•3) Repeat
st eps
1)
and 2)
•until na further lmprove-
ment •observed.
See IS
T ab le 2.
CH Frequency Voltage
CH1 30 MHz Voltage at TP106 0.9-1.2 V
CH2
41.005 MHz Voltage at TP106 5.5-6.5 V
CH3
54 MHz Voltage at TP106 1 2.5-13.5 V
Table 2
- 10 - •

VHF AIR, Hl and UHF LO Bands
Step Control Setting
Test Instrument Adlust Remarks
Connection
OFF/ VOLUME Contral: Connect DC SSVM
to TC105
1)
Select channel 12 and
ON
TP106 and GND . T112
adjust TC1 05 for 13 V on
SQUELCH Control: CCW
the DC SSVM.
Select channel 4through -2) Selectchannel 4 and ad-
412. lust
T1 12 for 1.0 V on
the
DC SSVM.
3) Repeat steps 1) and 2)
until impravement •
no IS
observed.
See Table 3.
CH Frequency Voltage
CH4
108 .0000 MHz Voltage at TP106 0.9-1.1
V
CH5
121.0000 MHz Voltage at TP106 2.4-3.1 V
CH6
136.0000 MHz Voltage at TP106 5.7-6.7 V
CH7
136 .0050 MHz Voltage at TP106 1.6-1.9 V
CH8
155.0000 MHz Voltage at TP106 4.1 -5.1 V
CH9
174.0000 MHz Voltage at TP106 11.0-11.8 V
CH10
380.0000 MHz Voltage at TP106 1.2 -1.6 V
CH11 451
.0000 MHz Voltage at TP106 5.7 - 6 .7 V
CH12
512 .0000 MHz Voltage at TP106 12.9-13.1 V
Table 3
•
•
UHF Hl Band
Step Control Setting
Test Instrument Adlust Remarks
Connectlon
OFF / VOLUME Contral: Connect DC SSVM to L114 Adlust L11 4
tor 12 V on
the
5
ON
TP106 and GND. DC SSVM.
SQU ELCH
contro tCCW See Table 4.
Sele
ct channel 15.
CH Frequency Voltage
CH13
806.0000 MHz Voltage at TP106 3.4-4.5 V
CH14
860.0000 MHz Voltage at TP106 6.5 -7.7 V
CH15
960.0000 MHz Voltage at TP106 11.8-12.2 V
Table 4
•
•
-11 -

RF Amp Alignment
VHF LO Band
Step Control Setting
Test Instrument Adlust Remarks
Connection
OFF/ VOLUME Contral: Connect instruments shown T101 1)
Select channel 2 and ad-
ON as Fig.3. T102
ju st T101 and T102 for
SQUELCH Control: CCW SWEEP GENERATOR maximum
RF waveform.
6Select channel 1through 3.
30-54 MHz. 2) Check channel 1thraugh
See Table 1. 3
for maximum output.
Aslight deviation as FigA
is acceotable.
VHF AIR Band
Step Control Setting
Test Instrument Adlust Remarks
Connection
OFF/ VOLUME Control: Same as Step 6SWEEP T103
1)
Select channel 5 and ad-
ON GENERATOR
108-174
T105
lust T1 03 and T1 05 for
SQUELCH Control: CCW MHz. maximum
RF output.
7Select channel 5through 6. 2) Check channel 4through
See Table 1. 6
for maximum RF output.
Aslight deviation as Fig.5
is acceptable.
VHF Hl Band
Step Control Setting
Test Instrument Adlust Remarks
Connection
OFF/ VOLUME Control: Same as Step 6. SWEEP
T104
1)
Select channel 7 and ad-
ON
GENERATOR T106
lust T104 and T106 for
SQUELCH Control: CCW
136.0005-174 MHz. maximum
RF waveform.
8Select channel 7thraugh 9. 2)
Check channel 7through
See Table 1. 9
for maximum RF output.
Aslight deviation as Fig.6
is acceptable.
UHF LO Band
Step controt Setting
Test Instrument Adlust Remarks
Connection
OFF/ VOLUME Contral: Same as Step 6 SWEEP TC101
1)
Select channel 10 and
ON GENERATOR 380-512 TC102
adlust TC1 01, TC102 and
SQUELCH Control. CCW MHz.
TC104
TC 104 for maximum RF
9Select channel
10 thraugh output.
12. 2) Check channel
10 through
See Table 1.
12 tor maximum RF out-
put. Aslight deviation as
Fi .7 is acce otable,
UHF Hl band: No adjustment requlred.
-12 -

No tes :
• Use TP10l for VHF Lo, Air
an d VHF Hi band adlustrnent.
• Use TP102 for UH F Lo band
adlustment.
Scope
•
'-"
Un it
TP10l!102
:;/
Under Test
f\
..,j,.
VH
Sweep
J,.
Generator
I
IJr
,.,.
'"
Ant Jack
Figure 3
-
-
136 .000 121.0 0
Freq (MHz)
Figure 5
10 S .00
•
,...
i'
'I
I
1,j\
I
I!I
QJ
U>
c- 3
o
Q.
U>
QJ
cr:
al 0
"C
-
-
54
41.005
Freq (MHz )
Figure 4
30
7i'\
I
IIr ,
II
i\
I
/:
J
I
~
o
QJ - 3
U>
c
o- 6
Q.
U>
QJ
cr:
-
-6
QJ
U>
C
o
Q.
U>
QJ
cr:
o
-
al
"C
- - 3
QJ
U>
C
o
Q.
U>
QJ
cr:
•
II
II
..!.
II
,
III
I1I
,II
,III
:I\!I
-
al
"C oh
II
IL
II
I,I
III
I1I
i!:-,
136 .005 155
Freq (MHz )
Figure e
174
3S0
451
Freq (MHz)
Figure 7
51 2
Overall Align ment and Se nsiti vit y Meas u reme nt
St ep Control Setting Test Instrument Adjust Remarks
Connection
•
OFF/ VOLUME Control: Connect FM
signaI TC104 Readjust TC104 for • gener- rnaxirnurn
10
ON
ator to the ANT jack and AC sensitivity.
SQUELCH ControtCCW SSVM to EAR
jack acrass 8
Select channel 10. ohm dummy load. Fig.8.
OFF/ VOLUME Control: Connect AM signaIgener-
n07
1) Adjust
T109 tor maximum
ON
ator to the ANT jack and AC n09
sensitivity.
11 SQUELCH Control. CCW SSVM
to EAR jack acrass 8 T110
2) Adjust T11 0
for minimum
Select channel 5. ohm dummy load. Fig.9. THD.
3) Readjust
T107 for maxi-
mum sensltlvlty.
OFF/ VOLUME Control: Same as step 10. T10e Adlust TC10e for
•
maximum
12
ON sensitivity.
SQUELCH CONTROL:CCW
Select channel 13.
A nt . Jack
Ear JackScope
Ant. Jack
Ea r Jack
Scope
Un it Unit
Under Test
~
Under Test
~
FM 8080
AM Signa' G enerator
Signa' Generator
Ohm
0Ohm 0
Figure 8 Figure 9
-13 -

Step Contral Setting Test Instrument Remarks
Connection
OFF/ VOLUME Contral: Connect FM signaIgenerator to
Turn off
the modulation and
ON the ANT jack and AC SSVM to
measure the (S+NI /N ratio.
SQUELCH controt CCW EAR jack across 8 ohm dummy
13
Channel as Table 1. laad. Set the signal generator to
each frequency as Table 1.
Set the VOLUME contral for
odB (0 .775 VI reading on the
SSVM.
No t e:
TP 104 is used to obse rve the AM band d etec tion output.
Zeromatic Function Test Procedure
r--i
6
7
I5
II
DA I I
I2
III-.3
L __ .J
t+ Q9
e3
Di scriminator curve
(Zeramatic functions when OUTPUT is in "L "level.I
O< e,< e3 e3 <e ,< e2 e2<
e, < Vcc
OUTPUT (IC4 Pin NO .8) H L H
Ta aclust the e, voltage.receive asignaI in the manual mode. and set T103 to obtain 2.7 V (1/2 Vee)
at TP-103. It is convenient to use the National Wea ther Service Signal for the adjustment.
In the e vent of Zeromat ic not funct ioning correctly, refer to "Reference Frequency OSC Alignment" (page
1Ol. an dcheck 118 .700000 MHz +10 H z. and adlust T103 again to 2.7 V DC while asignal is being
received.
-- 14 -

Key Access Pulse Output (IC1)
88u sec
II
IE
>i
P30 II
IJ
I I II
II
P31 IjI
I,
II
P32 II
fj
I
IIII
•
III
P33 II
II
I
III I
,,
III
P40
IS
:I
II
III
I'
1 : I
P41 n
iS
I
:I
Ij
I
III1I
P 42
nIII I
q1I
/I
1II
, I
III
P43 II
\\
nn d I
1 , III
> 11< 8u sec
I1 8use c
> 1''''' 1
II II 1
II
306us ec I
~ I
' ''''
II
I
IE
162.2msec > 1
II
I
Note:
Set KEY-LOCK SW to OFF, and do not push any key
•the Program Mode.m
PLL Data Waveform (lC1)
143us ec
, I
r< "' I
I I
143usec
I 1
IE "'I
I 1
143 usec
I I
t< =-1
1 1
I
I
I
I
I I I
I 11
63usec t--I I
Ii
11
11 12usec
-+j , .
II
143us ec
I I
1< ~ I
I,I,,•,,,I
, , •, I I,I,.,
'"
,,,I
IJ ,,I
••,
',..
:-
I-
I1
II
I
L..
L.
L.
32u sec
, I
~ ~
II
DA TA
(Pin8 01
CLOCK
(Pin7 81
N ot e:
Enter 150.0 00 0 MH z to channel 1 and loek out other channe ls .
Observethe wavefarm while scannin
g.
-15 -

Reception Check
POWER ON
Does
DISP
LAY
:> NO
pr op ertv?
./
YES
t
Does
SO tunet
ion
NO
:>
<and
sc an wh en SO
is
ON 7
./
YE S
,t
Does
kev-en
try w ork
N O
pro per ly 7
YES
Is Power Supp ly
..
OK 7
crrcurt
.1
. ./ Does
~ t h e Un it produce
NO
NOISE when Vo lume Is Voltage regula
tor
con tr ol is turned clock- (IC3) OK?
wise
?( SO :co unter
c lo ck wi sel
1.
YES
Is I Cl
clock osc illa tion
wav efa rm or r es et
OK ?
Is rec ep tion
t
OK when correct ~N O
<,
freq ue ncies ar e
Is CP U control circuit
enrered?
OK ?.
YE S
•IsDC-DC converter
Is Keyboard and/or
Do es (which consistsof Is
ICl OK '
~ N O
as soc ia ted circuit
OK I
07 ,8) OK?
Mem
ory tu netion
w
or k OK I
./
YES
Is the backup capac it or Is Voltage
re gu la tor
circu
it (which consists
Is ICl re se t properly?
(IC 4) OK?
of 01, 2 and 5) O K?
END +
~
IsC PU con trol circuit Is
th e band selection a
nd / or
Is IF Amp or No ise
{w hich con si st s of Is
IC10!
Amp circu it (I Cl O l)
(which co ns ists of
ass ociated circuit OK '
IC
S, 0 4) OK? 0 10- 14) OK?
OK ?
1
Is me mo ry pow er
IsPLL circuit (w hich IsMute circuit
sup
ply circuit (which consi
sts of IC7, 8) (
01 9) OK ?
cons
is ts of IC3) OKI OK ?
Is VCO circu it
Is Audio Amp (IC9) Is
ICl OK?
(which consists of
OK ?
0 114
,11 6 and 118)
OK?
- 16 -

Memory Check
Note1: Prior to checking the CPU System. mea-
Ivoltage
to ICs. (See schernat-
)klng the following items. the
atch up." If sa, push RESET
about one second and then
esure th
at elther the built- In
es or the external power is
this check.
sure supp y
POWER ON
ic diagram.
Note 2: While chec
ICs can
'"
switch for
Enter (program)continue. B
150,000 in CH1
AA batteri
present
on
Power switch OFF
'"
Does
4
.5±0.3 Vexist
NO Defective back-up
at Pin 7
of
circuit, IC3, D3.
ICl?
1YES •
Power switch ON
..L
Is 150,000
Defective CPU control
NO
displayed
at
:>
ci rcuit, Q4, IC5
CH1? and
/or IC2.
iYES
Remove batteries (or
Ext. power) and then
insert
them after
1
hour.
Power switch ON
l.
Is 150,000
NO
Defective back-up
<,
displayed at
capacitor (C4)
CH1?
./
YES
MEMORY ci rcuit is
OK
- 17 -

I
TROUBLESHOOTING
Symptom Cause
/Reme dy
1)
Di splay dose not light and no sound
1)
Defective batteries: Change batteries.
when POWER is on. 2) Wrong polar
ity of batteries:Correctthe polar ity of batteries.
Volume contral: MAX. 3) Defective extern
al power jack or charge jack:Replace.
Squelchcontrol: counterclockwise 4) D
efect ive ON -OFF switch on volume control: Replace.
(CCW)
1)
De fect ive speaker or EXT. SPKR ja ck : Replace the detective parts.
2) Detective audio amplifier ICg and
/or associated circu it components: Re place
2) Display lights but no sound. the defe
ct ive components.
3) De/ective
IF amplifier IC101 an d/ or associated circuit components: Repl ace
Volume contro
l: MAX.the defe
ct ive components.
Squelchcontrol: CCW 4) Defective fu
nct ional squelch contral and /or associated circuit components:
Rep lacethe cete ct ive components.
5) Defective a1 g,
IC1 and /or associated circuit: Replace the defective parts.
3 ) Sound co
me sout but display dose not
light.
1) Defective LCD or rubber connector: Rep la ce the defective parts.
Volume con
tr ot MAX.2) Defective
IC 1 an d /or associated c irc uit: Re place the detective parts.
soueicn control: CCW. •
1) De
fect ive IC101 and/ or associated circu it cornponents: Replace the
4) Does not scan and squelch does not de
fect ive components.
operate.2) De
fec tive IC1 and/ or associated circuit components: Re place the defective
components.
1) Defective IC1 and
/or associated circuit components: Replace the defective
5) Does not scan b
ut squelch operates. components.•
6) Displays in correctly and/ or unable to
1)
Defective Keyboard and /or associated circuit: Replace the dete ct ive parts.
enter correctly when RESET switch is 2) Defective
CPU (lC1) and/ or associated circuit: Replace the defective parts.
pushed.
7) Displays correctly at the time of pro-
gramming. But
aft er scanning, it be-
1)
Defective CPU (lC1) and /or associated circuit: Rep lace the d etect ive parts.
comes taulty,
8) MANUAL select operates but SCAN1) Squelch contral is not adlusted right: Turn soue
ten contral clockwise.
does n
ot operate. 1) Fau
lty connec ti on between linear and logie PCBs: Replace the defective
pa rts.
All
ba nds do not operate b ut display is 2) D
efective a15 -18 in low-pa ss filter: Replace the defective pa rts.
g)
3)
Defective IC7, 8 and/ or associated circuit: Replace the defective parts.
OK. 4)
De fect ive ei. 2, 5 voltage regulator and/or oz .8, 06 , 7, 30, 31 D C- DC
converter circu it and/ or a3 , 6 power saving circuit: Replace the de fect ive
pa rts.
- 18 -

)
Symptom Cause
/Remedy
10) V HF Lo ( Mi d) band does not operate 1) Detective
0101-104, n01, 102 Tuning circuit and /or 0114 VCO circuit:
bu t Air, VHF Hi, UHF Lo and
UHF Hi Replace the detective parts. .
band operate.2) Detective 010 and/ or associated circuit: Replace the detective parts.
11) Aircr
aft band does not operate but
1)
Detective 0111 and /or associated circuit: Replace the detective parts.
VHF Lo, V
HF Hi, UHF Lo and UHF Hi 2) Detective AM IF Amp including 0111, 112: Replace the detective parts.
band operat
e.
3) Detective
011 in band switch circuit: Replace the detective parts.
12)
VHF Hi band does not operate but VHF
1)
Detective 0105, 109, rt 04, 106 and/ or associated circuit: Replace the
Lo, Air, UH F Lo and UHF Hi band detective parts,
operate. 2) Detective
012 in band switch circuit: Replace the detective parts.
13)
UHF
Lo b an d does not operate but
1)
Detective 0104 .105, 0115 and /or associated circuit: Replace the detective
VH F Lo, Air, VHF Hi and UHF Hi band parts.
operate. 2) Detective
013 in band switch circuit: Replace the detective parts.
14) UHF Hl band does not operate but
VHF
1)
Detective 0106 -1 OS. 117 and/ or associated circuit: Replace the detective
parts.
l.o, Air,
VHF Hi and UHF Lo band 2) Detective
0118 VCO circuit: Replace the detective parts.
operate.
3)
Detective 014 and /or associated circuit: Replace the detective parts. :
15) Does not make beep tone.
1)
Detective 020 and /or associated circuit: Replace the detective parts.
2) Detective
IC1 and /or assoclated circuit: Replace the detective parts.
16) LOW BA
TT does not indicate when Detective IC4 and
/or associated circuit: Replace the detective parts.
1)
ba tt ery voltage went down. .
17) "Zerom atic " does not operate or holds
1)
Detective IC6, 09 and DA1 in Zeromatic circuit: Replace the detective parts.
2) Discriminator coll is out ot adjustment: TP103 shall have 1
/2 Vcctapprox.
dri
ft ed trequency at search
on
a2.7 V) in normal receiving mode.
operation. 3) Reter
to "Reterence Frequency OSC Alignment" on page 10.
Important Note:
Pulse, g en erated while checking circuits and/or certain combinations of key eperatton may cause
imp raper operatlon. Ta clear the maltunetton. re-initialization of CPU is necessary: Push RESET switch
while pressing ICLEAR I. and then release the RESET switch. All channels (200 ch) will be cleared and
freque
nc y indicator displays 000.0000. (Be sure the power is on when doing the above.)
- 19 -

WI RING DI AGRAM
8att Terminal
Wht
Red
VR 101
~ __ ~~-I sa Cont
Bik
Red
Speaker
SPKI
o
o
-.:::::::::::-0
o
VR I02
AF Cont
Yel
Grn
JIOI
Ant
*
LSOI
CNI
1-· •••• •• ••••••• el
CN2
(
..,r ... ~ Cl l r-
......- CNI03 0b '=1
---------..,
re • ••••••••••••• !J
I:' - cNïb2~ -:' - - -
Soldering tor
Bracket, PCB «»
I I
I I
I I
II
II I
I I
I I
.... ,
L
----
,
l
* Used tor Canada Model
- 2 0-