Realistic PRO-2022 User manual

PRO-2022
Desk-Top Programmabie Scanner
Catalo g Number: 20-127/9127
© 1989, Tandy Corporatlon.
All Rights Reserved .
RealIstic and Radio shack are reglstered trademarks of Tandy Corporatlon .

CONTENTS
Content,
S pec ifi ca tions.
BIOCkDiagram
Prin dpl es of Operation
General Op eratioo Dutline ,
AlignmenljAdjustment __ '" ,"" "" " ' " .
MemoryCneck . " " .
Reception Check
Troubleshooting . .
H ead phone Jack PCB (To p Views) ,
Headp hone Jack PCB (Bo nam Viewsl
Main PCB (TOP views)
Main PCB (Bottam Views)
Wi' ing Diagram
DisassembiylExpioded View
Electrical Part, List ,
Mec~a nica l Parts Li st _
Se miçooo ucto r Lead Ide mifieation a rJd IC Diagram
Microprocessor(IC7) Port Format
Append ix , .
Power Transtermor s pecrue
ate n
sere r-ene Diagram
PRODUCT SAFETY NOTICe
Page
z
s
,
s
t
Many eteClrical arld mechanical parts in this chassis have special characleristics These enereeter-
isties aften p ass uoroucec ene (he protect ion anorceo by the m eeroot ne ce ss.arily oe obtaireo by
us ing replacement com ponenI S rale<! lor highe r voltage, w anag e, etc. Replac eme nt patt s lhat have
the se sp ec ial sa fety c hara cle, istic, a re ident if ied in tlli, mamJaIa nd it, su pplements: electrical com-
peneuts having suc h features a re i de ntitied by a -' in tlle sc llemat ic diag ram and the parts list.
Belore replacing
an y of tne se corn ponentë. reac the pa rtë list in lhis ma nual carefully. Tr.e use ol
subs titute re placeme nt parts that do nol have the sa më safety char a ctënsncs as sc eenee in ee
part s Ii>l may c reate shock , fire or other h aza rds.
-,-

CONTENTS
Page
Contents ........................................................................ 2
Specifications . . . . . . ............................................................3
Bloek Diagram 4
Pr inciples of Operation 5
•
Genera lOperation Outline .......................................................... 7
Alignment/Adjustment 9
Memory Check 16
Reception Check 17
Troubleshooting 18
Headphone Jack PCB (Top Views) 20
Hea dphoneJack PCB (Bottorn V iews ) 20
Ma in PCB (TOP Views) 21
Ma in PCB (Botto rn V iews ) 23
Wiri ng D iagram 25
Disassembly/Exploded View ....................................................... 27
Ele ct r ica lParts List ............................................................... 29
Mec ha ni cal Parts L ist ........................................................... .. 44
Semic on ductor Lead Identification and IC Diagram 45
Microprocessor (IC7) Port Format 52
Ap pend ix ....................................................................... 53
Powe rT ra nsformer Specification 54
Schemati c D iagram 55
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in this chassis have special characteristics. These character-
istics aften
pass unnaticed and the protectlon afforded by them cannot necessarily be obta ined by
u si ng rep lacement components rated for higher voltage,wattaqe,etc.Replacement parts t hat have
th ese spec ial safety characteristics are identi fi ed in th is manua l and its supplements; electr ical com-
ponents
ha ving such features are ident if ied by a in the schematic diagram and the parts li s t.
Be fore rep lacing any of these components, read the parts list in th is man ua l carefu ll y. The use of
substitute replacement parts that do not have the same safety characteristics as specif ied in the
parts list may create shock, fire or other hazards .
- 2-

SPECIFICATIONS
30 MHz - 54 MHz 5 kHz steps
108MHz - 136 MHz
25 kHz steps
136.005 MHz
-174 MHz5 kHz steps
380 MHz -512MHz
12
.5 kHz steps
806.0000 MHz - 823.9375 MHz
851 .1125 MHz - 868.9375 MHz
896.1125 MHz - 960.0000 MHz
12.5 kHz steps
UNIT NOMINAL
LIM IT
pV 0 .5 2 .0
pV 2 .0 5 .0
pV 1 .0 2 .0
pV 1 .0 4.0
PV 2.0 4.0
IlV 1 4
dB 25 15
dB 20 10
kHz :!: 9 :!: 1"2
kHz :!:15 :!:18
dB
50 40
dB 50 40
dB 50 40
Not specified
70 60
:!:8 :!:5
45
30
35 25
45 30
35 25
35 25
3 5
8 6·10
4 3-5
2 1-3
1 .0 0 .8
dB
kHz
dB
dB
dB
dB
dB
mV
channels/sec
channels/sec
sec
W
*2
*2
*2
*1
T.H.D. 10 %
Any 200 channels in any band combination
UHF Hi
UHF Lo
VHF Lo
AI RCRAFT
VHF Hi
Power Source
Liquid crystaldisplay
Direct Key entry Digital-Controlled Synthesizer,Superheterodyne
tst IF: 10.7 MHz 2nd IF: 455kHz
AC 120
V, 60Hz, 15 W
DC 13.8
V, 8 W
Jacks Headphone, External speaker and "SNC" type antenna connector
*1 68-88 MHz
for 20-9127
*2 806-960 MHz for 20-9127
Residual
No ise
Scanning Speed
Scan Delay Time
Audio
Output Power
Channels
of Operation
Channels.Frequency
and
Mode display
Receiving System
VHF Lo
FM
AIRCRAFT AM
VHF Hi FM
UHF Lo FM
UHF Hi FM
Threshold
Tight VHF Lo, Hi, UHF
Aircraft
-6 dB
-50 dB
Spurious Rejection VHF Lo at 40 MHz
(except primary Image) AIRCRAFT at 124 MHz
VHF Hi at 154 MHz
UHF
IF Rejection 10.7 MHz at 154 MHz
Modulation Acceptance (EIA RS-204-A)
Signal
to Noise Ratio VHF Lo at 40 MHz
AIRCRAFT at 124 MHz
VHF Hi at 154 MHz
UHF Lo at 450 MHz
UHF Hi at 860 MHz
Vol. Min.
Fast
S
low
Selectivity
Squelch Sensitivity
Sensitivity
Frequency Coverage
Note: Nominal specs represent the design specs: all units should be able to approximate these -some wiJl ex-
ceed and
some may drop slightly below these specs. Limit specs represent the absolute worst condition that still
might be considered acceptable; in
no case should aunit perform to less than any limit spec.
-3-

BLoeK DIAGRAM
LOW /AIR/HI /RF AH?
+---~ AGC CONT . MIX f-1.-(
01 02 03
[ill)
o
30-54MHz
108-136HHz
136 .005-174HHz
10.7HHZ
IF AH? I--~
018
CRYSTA L
FILTER
AGC
10 .245MHz
,.....-i 'o 'h
, ,
OSC MIXER
IF AH?
O UAORA T URE .OET
NOl SE AH?
ICI
I SO UELCH I
>
I-
369 .3-501 .3MHz 118 .7-167 .1MHz
TRIPLER lE-....---t VCO (AIR/HI!
011 UHF LOW) ~
09 010
380-512MHz
UHF LOW RF AH?
MIX
04 05
806-960MHz
8UFFER
08
40 .7-64 .7HHz
VCO (LO W)
06 07
CERAMIC
FILTER
455KHz
AM IF AH?
OET.
022 023
I
,UHF
Hl RF AM P.
MIX
012 013 014
~ -J 816 .7-970 .7MHz
00 U8 LER
016 JE-
408 .35-485.35M Hz
VCO (UHF H IJ
015 017
SWITCHING
019
LO W
AIR
HI
GH
U HF LOW--.1
UHF Hl --.1
8 ANO SE LEC T
026- 32
ZE RO MA TIC
I C2 024
MUTE
02 0 021
lY:ïlLïiMEJ < >fo
~
,....-------, I; HE AO
AU OIO AMP . '" PHONE
IC2 IC3 ~
/
I
t--I--{')
'-'
AC120V
(240 V)
RECTIFIER
060
OC 13. 8V
036
,....---t---;. :. ---,
0 ,57
I-.+------t-~ , ---+---(
037
,....-- .
., ,....---------'
VOLT AG E
REG U LA TOR
lC5 040
VOL TAGE
REGU LATOR
rC 4
1 ..-- --- -'- --- ---,
OC-OC
CONVER TER
034 035
054-56
MEMORY
(RA M)
IC6
5 .6V
CP U
IC7
CPU CONTROL
033 041
Y ' 0' f-J
2 HHz I I I
PLL
rC8
LCD
6
.4 M Hz
~:O~
LOW PASS FILTER ~--J
036 037 038
I
K EY B OARD
De-AC
CONVER TER
025
LOW BAH .
OE T.
rC2 (1/ 4)
9V BAH .
- 4 -

PRINCIPLES OF OPERATION
The PRO-2022 is a Phase Locked Loop (PLL) synthesized VHF/UHF, FM receiver,controlled by aCentral Pro-
cessing Unit (CPU) via a keyboard.
The VHF Lo band (30 - 54 MHz)
or VHF Hi band (136.005 - 174 MHz) is received in 5 kHz increments, and the
UHF Lo band (380 -512 MHz)
or UHF Hi band (806 - 960 MHz) is set up to be 12.5 kHz increments.Similarly, the
aircraft band (108 -136 MHz) is in a 25kHz step.
All functions such as receiving frequency range,frequency determination,scanning and delay time,etc., are con-
trolled
by the CPU. The CPU is able to do only the assigned functions, and no modification of the CPU is feasible.
The following paragraphs explain the operation of the circuit in terms of the functional blocks:
AvariabIe capacitance
diode (varactor) tuning ("Automatic Tuning System ") is employed on all Bands.
Field-effect transistors (FET) are used in the RF/MIX circuits
of 10 and hi bands, to achieve optimum mlx-rnodula-
tion and mutual-modulation characteristics. Q18 amplifies the 10.7
MHz IF. A10.7MHz monolithic crystal filter is
incorporated to obtain a good IF selectivity.
IC1 contains the local oscillator, mixer, IF amplifier, quadrature FM detector, noise amplifier. Acrystal oscillator
produces
10 .245 MHz.which is mixed with 10 .7 MHz.resulting in 455 kHz IF. A 455 kHz ceramic filter is providec
to increase the IF selectivity. The 455 kHz IF signal is amp lified in the IF amp stage,and the quadrature FM detec-
tor detects it to an audio signa !.
The detected output of FM is applied to IC3. IC3 amplifies the audio signals and drives the speaker.
IC7 is the CPU. The CPU does data processing, calculation etc.Any unstable supply voltage
(V DD) to the CPU can
cause the CPU
to malfunction,such as wrong data processing, wrong data transfer etc. To overcome this, C164
and R167 in the
logic circuit "initializ e" the CPU. (Refer to the schematic on page 55 .)
The initialization is done as soon as AC plug or external power is connected. Figure Ashows the initializing wave-
form.Memory back
up function is automatically started whenever the initialization has been done.
The RESET switch is located in the hole on the read panel and is used
to correct an LCD or keyboard maltune-
tion. The initialization of the CPU, mentioned above can also be
done by pushing RESET.
Key inpu
t, receiving frequency,etc. is managed by the CPU, and CPU output drives LCD.
CX1 (2 MHz) is a ceramic oscillator clock which is used for CPU control. Figure Bshows 1/8 divided waveform of
Figure C.
•
-5-

IC7 Pin G)
Voo - --
--- -- - ---
- - - -
Vool2 --
--
----
I
I
I
II
1+ 320-.l
I"'ifC I
I
Figure A
Figure B
o
V
f---
I
I
I
I -
I
4usec
I
I
I
I
4.4
IC7 Pin @
: IC I Voo :4.4V
V
~---
-
f- - - ,
~_ lo[
V
IVVVV
,vvV
I
V
.-
v
4usec I
,I
,
I
-,
4.2
O.2V
IC7 Pin @
Figure C
-6-

GENERAL OPERATION OUTLINE
Turn power SW on.Automatically sets to
SCAN mode and starts scanning when the
sa is on. To sta
rt DI RECT search, press [ ~ ]or I T) key.
No reaction when the frequency is 000.0000.
Press RESET SW, located at the battery
compartment. Press [MANUAL].
Scan Bank 1
thro ugh 10 are displayed. T0
ho ld the channel, press [DELA Vl .
If there is any blank scan bank, press the (When this channel is not set
to DELAY.)
number key
to light all scan banks, and to
blink one of them in one after another.
To release the delay tunetion. press [DELA
Y]
•
Press [1] throuqh [9] ke y. a
çam .
Scan Bank 1 through9will disappea r.
To skip certain frequency. press [ UO UT ].
Press [0] key.
No res po nse. (When this channel is not set
to UOUT .)
Press [1) through 19) keya nd [0] key. Scan T0release the Loek Outfunction, press
Bank 1 through 9are displayed excepl
O.
[UOUT] again.•
I
Press [SPEED]that speed •To obtain priority operation in manual mo de,
so scanIS
changed in two speeds, fa st or s lo w. press [P
RI ].
I
Press [SPEED] t
ha tspeed •
To release the priori ty tunetion. press [PR I]so scan IS
changed to the other. • aqa m.
T0obtain priority operation •scan mode,Press [PGM] to set to program mode. In
press [PRI].
•
To release
pr iority operation,press [PRI] *1
*2
•
aça m,
Press [MANUAL].When [MANUAL] •
IS
pressed again, the channel advances. To
select one of 1 through 200 channels, push
the number key and then push [MANUAL].
-7 -

*1
I
Enter the desired frequency in each channel
as follows:
1
Enter the desired frequency with numeral
keys.
I
Press [ENTER] to memorize the frequency.
If wrong frequency (out of the band) is
entered, "Error" will be displayed.
Press [CLEAR], then enter the correct
frequency. 1
Press [PGM] to advanee to next ehannel.
Enter the frequeney and press [ENTER].
Repeat it to memorize frequencies one by
one.
Press [PRI]
50 that priority channel appears.
To revert to the previous channel, press [PRI]
again.
i
Press numeral keys (1 through 200) and then
press [PRil.
Priority channel will be changed to newly
entered channel. I
I
*2
I
Enter search frequency as follows.
I
Press [LIMIT] and enter the lower frequeney
of the range to search with numeral keys.
I
Press [ENTER]. I
Press [LIMIT] and enter the upper frequeney
of the range to search.I
IPress [ENTER].
Press [
.... ] to search from lower frequeney.
Press
[., to search from upper frequeney.
(squeleh must be on).
I
Press [MaN] to store the desired frequeney
(10 monitor channels) in the search mode.
I
To start search, press [ .... lor l.I.
To eall monitor channets,press [MaN].
I
I
I:
!
I
Press [MaN]
sa that next monitor channel I
appears. I
I
To call the monitor channels directly, press
numeral keys. I
To revert to the previous ehannel, press
[PGM].
- 8-

ALIGNMENT/ADJUSTMENT
Alignment and Test Points Locations
~
P 6
Til
. &I ~
~ T1 0
Cilll-.m
Alignment Preparation
TC2
1TP2\ qmT2
~ ~
T7~
TC6 ~~
I!J T C ~ T 6cillJ
~~
• T8
LI3 Iii:l
,A, TC_ T9 ~
I!J ~ 1!J TC3
~
TC7
I!J
Test equipment required
Oscilloscope (0 -500 kHz, 0 - 50 MHz)
AC SSVM
DC SSVM
Frequency Counter (200 MHz)
a-ohm
dummy load
Slow Sweep Generator with variabie marker (10.7 MHz)
VHF Sweep Generator with variabie marker (30 -54 MHz, lOB
-174 MHz)
UHF Sweep Generator with variabie marker
(3BO -512 MHz)
FM Signal Generator (30 -54 MHz, 136.005 -174 MHz,
3BO -512 MHz, B06-960 MHz)
AM Signal Generator (108-136 MHz)
Note:
• Use non-metallic tuning tools,
• The test equipment and receiver should be warmed up at least 10 minutes before proceeding to alignment.
• The signal level trom the generator should be kept as low as possible to obtain the usabie output.
Program
CHl to CH15 as follows.
Table 1
Channel Frequency(MHz) Channel FreQuency(MHz)
1 30.0000 9 174.0000
241.0050 10 380.0000
354.0000 11 451.0000
410B.0000 12 512.0000
5121.0000 13 806.0000
6136.0000 14 860.0000
7136.0050 15 960.0000
B155.0000
-9-

Alignment Procedures
Reference Frequency ose Alignment
Step Contral Setting Test Instrument Connection . Adiust
Remarks
OFFNOLUME Control: ON Connect Frequency counter TC7 Adjust TC7
50 that the frequency
SQUELCHControl. to TP3 through a ceramic ca- is 11a.
700000 MHz±10Hz
1Fully counter clockwise :pacitor (5-10 pF) and GND.
(CCW) Figure 1
Select Channel 4.
IF Section Alignment
Step Control Setting Test InstrumentConnection Adiust
Remarks
OFFNOLUME Control: ON Connect test instruments as T7 Adjust T7 to symmetrize the
SQUELCHControl: CCW shown in Fig. 2
Tl0
upper and lower heights of the S
2curve to be equal and adjust Tl 0
to symmetrize the left and the
right of the S curve.
Note:
During alignment. maintain the sweep generator output at the lowest level possible to prevent overloading.
Figure 1 Figure 2
Scope
TPS
Unit
Under Test
10.7 MHz
.01IJF Sweep
Generator
TPl
S·lOpF
I
TP3
-
Unit -" Frequency
Under Test
Counter
rl-r
VCO Alignment
VHF Lo band
Step Control Setting Test Instrument Connection Adiust
Remarks
OFFNOLUME Contral: ON Connect DC SSVM
to TP4 TC3 1) Select channel 3 and adjust
SQUELCH Contral: CCW and GND. Ta TC3 for 13V on the DC
3SelectChannel1through 3.
SSVM.
2) Select channel 1 and adjust
Ta for 1.0 V on the DC
SSVM .
3) Repeatsteps 1) and 2) until
no further impravement is
observed. SeeTable2.
CH FreQuency Voltage
CH1 30 MHz Vottaoe atTP40.9-1.2V
CH2 41.005MHz
VoltaQe at TP45.5-6.5 V
CH3 54 MHz Voltageat TP412.5-13.5V Table2
-10 -

VHF Air, Hi and UHF La bands
stee
Control Settina !Test Instrument Connection Adiust ] Remarks
,I1) Select channel 12 and
OFFNOLUME Control: ON IConnect DC SSVM to TP4 TC4 I
SQUELCH Control: CCW i and GND. T9 adjust TC4 tor 13V on the
4IDC SSVM.
Select Channel 4 through i2) Select channel 4 and adjust
12. I
IIT9 tor 1.0 V on the DC
ISSVM. I
!3) Repeat steps 1) and 2) until
ino turther impravement is
Iobserved . See Table 3.
UHF Hi band
CH Frequencv Voltage
CH4 108.0000 MHz Voltage at TP4 0.9-1.1 V
CH5 121.0000 MHz Voltace at TP4 2.4-3.1 V
CH6 .136.0000 MHz Voltace at TP4 5.7--6.7V
CH7 136.0050 MHz
Vohaoe at TP4 1 .6--1 .9 V
CH8 155.0000 MHz Voltage at TP4 4.1-5.1 V
CH9 174.0000 MHz Voltaceat TP4 11.0-11.8 V
CH10 380.0000 MHz Voltage
atTP41 .2-1.6 V
CHll
451.0000 MHz Voltage at TP4 5.7--6.7 V
CH12 512.0000 MHz Voltage at TP4 12.9-13.1 V Table 3
stee
Control Settina iTest Instrument Connection Aclust ' Remarks
OFFNOLUME Control. ON IConnect DC L13 I
SSVM to TP4 Adjust L13 tor 12 V on the DC
SQUELCH Contral:CCW iand GND. SSVM.
5Select Channel 15. ;SeeTable 4.
!
i
CH Freauency Voltaae
CH13 806.0000 MHz Voltaae at TP4 3.4-4.5 V
CH14 860.0000 MHz Voltage at TP4 6.5-7.7 V
CH15 960.0000 MHz Voltage at TP4 11.8--12.2 V
-
11 -
Table 4

RF Amp Alignment
VHF Lo band
Step Control Settina Test Instrument Connection Adiust Remarks
T1 1) Select channel 2 and adjust
OFFNOLUME Control: ON Connect instruments shown T2 T1.and T2 tor maximum RF
SQUELCH Control:CCW as Fig.3. wavetorm..
6Select Channel 1 through 3. SWEEP GENERATOR 2) Check channel 1 through 3
See Table 1 30-54 MHz. tor maximum output.
A slight deviation as Fig.4 is
acceptable.
VHF
Air band
Step Control Settina 1Test Instrument Connection Adiustj Remarks
IT3 I1) Select channel 5 and adjust
OFFNOLUME Control: ON !Same as Step 6 SWEEP T5 T3 and T5 tor maximum RF
SQUELCH Contral: CCW !GENERATOR 108-136 MHz. i
ioutput..
7Select Channel 5 through 6. 1 . I2) Check channel 4 thraugh 6
See Table 1. !Itor maximum output.
IA slight deviation as Fig.5 is
IIacceptable.
!I
VHF H' b d
Ian
Step Control Setting !Test Instrument Connection Adlust Remarks
.T4 I1) Select channel 7 and adjust
OFFNOLUME Contral: ON lSame as Step 6SWEEP T6 T4 and T6 tor maximum RF
SQUELCH Control: CCW IGENERATOR !wavetorm.
8Select Channel 7 through 9. 136.0005-174 MHz. 2) Check channel 7 through 9
SeeTable 1. tor maximum output.
A slight deviation as Fig.6 is
iacceptable.
,
UHF Lo band
Step Control Setting Test Instrument Connection Adiust Remarks
!TC1 I1) Select channel 7 and adjust
OFFNOLUME Control: ON iSame as Step 6 SWEEP TC1, TC2 and TC5 tor
SQUELCH Control : CCW GENERATOR 380-512 MHz. TC2 Imaximum RF output.
TC5
9Select Channel 10 through 2) Check channel 10 through
12. See Table 1. 12 tor maximum output.
A slight deviation as Fig.7 is
acceptable.
I
UHF Hi band: No adjustment required.
- 1 2-

An t. Jack
Scop e
TPl /2
Unit
~
Nates:
Unde r Test Use TP1 tor VHF La, Air and VHF Hi band adjust-
.,j,.-
•ment.
Sweep •Use TP2 tor UHF La band adjustment.
Generator
Figure 3
a:
~I
. ol
"'C
(\
?
1\
(]
».
5\ 111
J\
c
0
1\
11
!ti
i-,
~
/ ;1
t:
a:
30
41 .00 5 54
108 .00
121 .00
136 .000
Freq ( MHz)
Freq (MHz)
Figure 4 Flgure 5
0
ê:i
ê:i
0
"t; .
~
:: - 3
~
- 6
c:
'"
c:
00
Sr
~
'"
.,
c::
a:
136.0 05
15 5
174
Freq (MHz )Freq (MHz)
Figure 6Figure 7
Overall Alignment and Sensitivity Measurement
Step Control Settlnq Test Instrument Connection Adiust Remarks
OFFNOLUME Control: ON Connect FM signal generator TC5 Readjust TC5 tor maximum sen-
to the ANT jack and AC
10 SQUELCH Control: CCW SSVM to Headphone jack sitivity.
Select Channel 10. across 8 ohm dummy laad.
Fig.8.
OFFNOLUME Control. ON Connect AM signal generator T7 1) Adjust T11 tor maximum
SQUELCH Control: CCW to the ANT jack and AC sensitivity.
11 Select Channel 5. SSVM to Headphone jack T11 2) Adjust T12 tor minimum
across 8 ohm dummy laad. T12 THD.
Fig.9. 3) Readjust T7 tor maximum
sensitivity.
12 OFFNOLUME Control: ON Adjust TC6 tor maximum sensi-
SQUELCH Contral: CCW Same as step 10. TC6 tivity.
Select Channel 13.
o
o
Scope
Un it
Unde r Test
Signal Generator
,..-...,...,....,.-
__ -, Heedphone Jack
o
o
Scope
Headphone Jack
Un it
Und er Test
FM
Signal Gener
ator
Figure 8Figure 9
- 13 -

Step Control Settlnq Test Instrument Connection Remarks
OFFNOLUME Control: ON Conneet FM signal generator to the Turn oft the modulation and mea-
SQUELCH Control: CCW ANT jack and AC SSVM to Head- sure the (S+N)/N ratio.
13 Channel as Table 1. phone jack across 8 ohm dummy
lead. Set the signal generator to
each trequency as Table 1.
Set the VOLUME control tor 0 dB
(0.775
V) reading on the SSVM.
Note:
TP6 is used to obserbe the AM band detection output.
Zeromatic
Function Test Procedure
Dlscrirnlnntor curve
(Zeromatic functions when OUTPUT is in "L" leveL)
Io<
e1 < es ea <e1 -cea Iea <e1 < Vee
I
OUTPUT (033 Cathode) IH L IH
To adjust the
e1 voltage, receive a signal in the manual mode, and set T3 to obtain 2.7 V (1/2 Vee) at TP5. It is
convenient to use the National Weather Service Signal tor the adjustment.
In the event of Zeromatic not functioning correctly, refer to "Reference Frequency OSC Alignment" (page 10), and
check 118.700000MHz ±
10Hz, and adjust T3 again to 2.7 V OCwhile a signal is being received.
- 14 -

Key Access Pulse Output (IC1)
88 usec
,,
~
P30 ,I
11
UU
P31 Jl I
P32
ti
I
P33
11
I
II
P40
il
IS
II
I1I
P41
I'
fl
d:r II
I. "
P42 ",II
II
1I
II
""
"P43
:1
"
---i III
"
11 I I
~ IE 8usec l
'E8 usec
11
~I I
I1
306 usec
11
IE :.1
II162.2msec
1< ;0.1
II
I
PLL Data Waveform (IC1)
143usec
1 ,
I~ "I
I 1
.,
143usec
I I
lil! Jol
I 1
.,
143usec
, I
loE ;;0.1
I I
143usec
, 1
~
II
o0
32use c
I ,
.., ~
,,
DATA
/Pin80 )
CLOCK -,n,nn
(Pin78l
I
II
L- ...J : ..... """":"'"1 _
I1
: n 'L
LATCH ------------~~III.-, -- - ------------- ----11-1"
I " 1I '
PULS E 1 I I
(Pin72l 63use c t--/I' I47usecL...l:
11 _.o.12usec
-l 1.12usec 11
Note:
Enter 150.0000 MHz to channel 1 and loek out other channels.
Observe the waveform while scanning.
- 15 -

POWER ON
Enter (program)
150,000in CHl
MEMORY CHECK
Note:
• Prior to checking the CPU System.
measure supply voltage to ICs. (See
schematic diagram.)
• While checking the following items,the
ICs can "Iatch up." If
50, push RESET
switch for about one second and then
continue.
Power switch OFF
Defective back-up circuit.
1C4 .
>------4 036
Power switch ON
NO Defective CPU control circuit,
Q33,and/or 041
IYES
Disconnect AC plug (or Ext.
power) and then insert them
after 1 hour.
Power switch ON
NO Defectiveback-up battery.
MEMORYcircuit is OK
-16 -

RECEPTION CHECK
POWER ON
NO
NO
NO
IYES
Is Power Supply circuit OK?
I
Is Voltage regulator (1C4)
OK?
Is IC7 clock oscillation
waveform or reset OK?
END
IYES
Is IC7 OK?
Is Key board and/or
associated OK?
Is IF Amp or Noise Amp
circuit (IC1) OK?
Is CPU control circuit OK?
Is Oe-OC converter (which
consists ol Q34, 35) OK?
NO
NO
IYES
Isthe backup battery OK? Is the band selection
(which consists of 026-29)
OK?
Is CPU control circuit
(which consists ol
023 .
041) OK?
Is
memory power supply
circuit (which consists ol
1C4, 036) OK?
Is PLL circuit (which
consists 011C7.ICS.
08)
OK?
Is VCO circuit (which
consists ol
06, 9 and 15)
OK?
Is IC1 and/or associated
circuit OK?
-17 -

TROUBLE SHOOTING
5ymptom Cause/Remedy
Display does not light and no 1) Detective AC Line Cord or ext. power jack: Replace.
sound when POWER is on. 2) Detective powertranstormer T201: Replace.
Volume control: MAX. 3) Detective Rectifier
06 : Replace.
Squelch control:counterclockwise 4) Detective voltage regulator: Replace.
(CCW) 5) Detective On/oft switch on volume control: Replace.
Display lights but no sound. 1) Detective speaker or headphone jack: Replace the detective parts.
Volume control: MAX 2) Detective audio
amp litier IC3 and /or associated circuit components:
Squelch control: CCW Replace the detective components.
3) Detective IF amplitier
ICl and lor associated circuit components:
Replace the detective components.
4) Detective tunctional squelch control and
/or associated circuit
components: Replace the detective components.
5) Defective
020 , 21, IC7 and /or associated circuit: Replace the
defective parts.
Sound
comes out but display 1) Detective LCD: Replace the defective parts.
does not light. 2) Defective IC7 and
/or associated circuit: Replace the defective parts.
Volume control: MAX
Squelch control: CCW
Does not scan and squelch does 1) Defective
ICl and/or associated circuit components: Replace the
not operate.detective components.
2) Detective IC7 and/or associated circuit components: Replace the
detective components.
Does not scan but squelch 1) Detective IC7 and/or associated circuit components: Replace the
operates.detective components.
Displays incorrectly and
/or unable 1) Defective Keyboard and /or associated circuit components: Replace
to enter correctly when RESET the defective components.
switch is pushed. 2) Defective CPU (IC7) and
/or
associated circuit components:
Replace the detective components.
Displays correctly at the time of 1) Detective CPU (IC7) and
/or
associated circuit components:
;programming. But after scanning, Replace the detective components.
it becomes taulty.
MANUAL select operates but 1) Squelch control is not adjusted right: Turn squelch
SCAN does not operate.controlclockwise.
All bands
do not operate but 1) Detective
036-38 in lowpass tilter: Replace the detective parts.
display is OK. 2) Detective IC8 and/or associated circuit: Replace the detective parts.
3) Detective
034 , 35, 054, 55, 56 DG-DC converter circuit: Replace
the defective parts.
VHF Lo (Mid) band does not 1) Detective
01-4 , Tl , 2 Tuning circuit and/or 06 , 7, 8 VCO circuit:
operate but Air, VHF Hi, UHF Lo Replace the detective parts.
and UHF Hi band operate. 2) Detective
032 and/or associated circuit: Replace the defective
parts.
- 18 -

Symptom
Cause/Remedy
Alrcraft band does not operate but 1) Defective 012, T3, 5and/or assoclated circuit: Replace the
VHF Lo, VHF Hl, UHF Lo and UHF defective parts,
Hl band operate. 2) Defectlve AM IF Amp Including 022, 23: Replace the defectlve
parts.
3) Defective 031 In band switch circuit: Replacethe defectlve parts.
VHF Hl band does not operate but 1) Defectlve 06, 10, T4, 6 and/or assoclated circuit: Replace the
Air, VHF
Lo, UHF Lo and UHF Hl defective parts.
band operate. 2) Defective
029 In band switch circuit: Replacethe defectlve parts.
UHF Lo band does not operate 1) DefectlVe
04, 5and/or associated circuit: Replace the defectlve
but Air, VHF
Lo, VHF Hl and UHF parts.
Hl band operate. 2) Defectlve
028 In band switch circuit: Replace the defectlve parts.
UHF Hl band does not operate but 1) Defectlve 012-14, 16 and/or assoclated circuit: Replace the
Air, VHF Lo, VHF Hl and UHF Lo defectlve parts.
band operate. 2) Defectlve 015, 17VCO circuit: Replace the defectlve parts.
3) Defectlve
027 and/or assoclated circuit: Replace the defectlve
parts.
Does not make beep tone. 1) Defectlve
1C3 and/orassoclated circuit: Replacethe defectlve parts.
2) Defectlve IC7 and/or assoclated circuit: Replace the defectlve parts.
LOW BATT does not Indlcate 1) Defectlve IC2 and/orassoclated circuit: Replacethe defectlve parts.
when battery voltage went down.
"Zeromatic" does not operate or 1) Defectlve
1C2, 024 and 033, 34 In Zeromatlc circuit: Replace the
holds on a drifted frequency at defectlve parts.
search operation. 2) DIscriminator
coU Is out of adjustment: TP5 shall have 1/2Vcc
(approx. 2.7
V) In normaJ recelvlng mode.
3) Referto "ReferenceFrequency OSC Allgnment" on page 1O.
Important Note:
Pulse, generated while checklng circuits and / or certaln combinations of key operation may cause Improper opera-
tion. To clear the malfunctlon, re-Initlallzatlon of CPU Is necessary: Push
RESET switch while pressing CLEAR, and
then releasethe RESETswitch. All channels (200ch) wlll be cleared and frequency Indicatordisplays 000.0000. (Be
sure the power is on when dolng the above.)
-19 -