Realistic HTX-100 User manual

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Realistic HTX-100 Service Manual
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®
§<_EALISt7C:....
••
erv1ce
HTX-100
10 M ~ ETER SSB/CW TRANSCEIVER
Catalog Number : 19-11 01
·TABLE OF CONTENTS
PAGE
Specifications . . .. . . .. . . . . .. . .. . .. . . .. .. . . .. . .. . . .. . .. .. . .. .. . . .. . . . .. . . .. .. . . .. . . . .. . . . . . . .. . .. .. . .. .. 2
Disassembly Instructions
................................. : ....................... . ................... :·:. 6
Block
Diagram......................................................................................... 7
Circuit Description . . . .. . . . .. . .. . .. . . .. .. . . .. . . .. . . .. .. .. . .. .. . . . . .. . . . .. .. . .. . . .. . . .. . . . . . . .. . .. .. . .. . . 8
Alignment Procedure
.................• , ......................... , . . . . .. . . .. . .. .. . . .. . . . . . . . .. .. . .. . .. .. 10
Alignment Points Locations
................................... : .......... . ......................... ·•. .. . 15
Troubleshooting Hints.. . . . .. . . .. . .. . .. . . .. .. . . .. . . .. . .. .. .. .. . . . . .. . . .. . .. . .. . . .. . . .. . . . . . . .. . .. . .. .. . . 16
PCB (Top and Bottom) Views
............ .. ..... ·. . .. . . .. .. .. .. . . .. . . . .. . . .. . .. . . .. . . .. . . .. . . . . .. . .. . .. . .. . 20
Wiring Diagrams ................................................................................. ·.. . .. . 25
Electrical Parts
List ........................... . .. . .......................... ." . . .. . . .. . . . . . . .. . .. . .. .. . . 27
Exploded View . . . .. . . . . . .. .. . . .. . . .. .. . . .. .. . . .. . . .. .. . .. .. .. . . . . .. . . .. . .. . . .. . .. . . .. . . . . . . .. .. . .. . .. . 48
Mechanical Parts List . . . . . .. . .. . .. . .. . .. . .. . .. . . . . .. .. .. . ... . . .. . . . .. . . .. . . .. . .. . .. . . . .. . . . . . .. .. . .. .. . 49
Transistor Voltage Chart
................................................................................ 51
IC Voltage Chart. . .. . . . . .. . . .. .. . . .. . .. . .. . .. . . .. . . .. .. . .. .. .. . . . . .. . . .. . .. . .. . .. . . . .. . . . . . .. . .. .. .. . . . 52
Semiconductor Lead Identification. . . . .. . .. . .. . . .. . . .. .. .. . ... . . . . .. . . .. . .. . .. . . .. . . .. . . . . .. . . .. . .. . .. .. . 56
IC Internal Diagram .................................................................................... _57
Schematic Diagram
...................... . ... . ................................... . ..................... 61
: c1988 Tandy Corporation.
All Rights Reserved.
Realistic and Radio Shack are registered trademarks of Tandy Corporation.

GENERAL
1. Frequency Range
2. Microphone
3. Speaker
4. Antenna Connector
5. Jacks & Connectors
6. Controls
7. Display/Indicators LCD
LED
8. Size
9. Weight
1
0. Accessories
11 . Power Source
MEASUREMENT CONDITIONS
1. Power Source
2. Antenna Impedance
·3. Test Temperature
SPECIFICATIONS
28.0000 ""29.6999 MHz
600 Q, Dynamic Type
8Q,5W
MType
MIC (8 PIN), DC Power (3 PIN), EXT SP (3.5~), CW Key
IN (3.5~), Phone (3.5~)
Mode selector (SSB/CW), ON/OFF Volume, Squelch, RF
Gain, Power HI/LOW Switch, RIT, NB ON/OFF Switch,
FrequencyDial, FreQuency/Memory UP/DOWN SW,
Store Key, 500 k Key, MEMO key, Step Key, F. LOCK
Switch, TX/RX Switch
Frequency Indicator, Memory Channel Indicator, Mode In-
dicator (CW/SSB) MEMO, TX Indicator
. RF/S Meter
2-
7/16"(H) X
7-
9/32"(W) X
7_7/
8
"(0)/
62 mm(H) x 185 mm(W) x 200 mm(D) (Unit)
4 lbs 3 oz (1.9 kgs) (Unit)
DC-Power Cable with Fuse
Microphone with UP/DOWN
SW
Mic Hanger
13.8 V DC +
15/-20 o/o, Negative Ground
13.8 V (DC)
50Q
4. SSB Modulation Frequency, Two Tone: 500 Hz & 2400Hz
5. Mean Signal Input Level
6. Reference Audio Output Power
7. Audio Frequency
8. Audio Output Load
SSB
cw
1000 j,tV
0.5W
1kHz
800Hz
8 Q Resistive
-2-

TRANSMilTER SECTION
ITEMS UNIT NOMINAL LIMIT
1.
Frequency Tolerance at 25°C (5 minutes after Swit~h on)
(SSB CW) Hz ±300
±1500
2.
Carrier Power
cw
HI w 25.0 22.5
"v 29.0
LOW w 5.0 3.0
"v 7.0
3.
PEP Power (18 Wpep +10 dB up Two Tone)
SSB
HI Wpep 25.0 22.5
"v 28.0
LOW Wpep 5.0 3.0
"v 7.0
4. Spurious Harmonic Emission
(SSB CW) dB
-50 -40
5.
Carrier Suppression SSB dB
-55
-40
6. Unwanted Sideband Suppression (at
2500Hz 4 Wpep 16 dB up Single tone)
SSB dB
-50 -40
7. Battery Drain
SSB: at No Modulation mA 800 1500
CW: NOT KEY Down mA 800 1500
8. Battery Drain SSB: MAX Wpep, Two Tone
HI
mA 3200 4500
LOW mA 1600 2500
CW: MAX Carrier
HI mA 5000 6000
LOW mA 2400 3200
9. Modulation Frequency Response (1 kHz, 0 dB Reference)
Lower at 450 Hz SSB dB
---4
-10
Upper at 2.0 kHz SSB dB
-6 -10
10. Microphone Sensitivity
SSB: For 10 Wpep Output mV 1.0 2.0
11. ALC Range
SSB: 18 -28 Wpep dB 50 40
12. CW Monitor Output mW 5 2.5
Av10
13. CW Monitor Frequency Hz 1000 850
'V 1150
14. CW Monitor Distortion
o/o
2.5 6
-3-

RECEIVER SECTION (NB Switch OFF)
ITEMS UNIT NOMINAL LIMIT
1.
Max. Sensitivity CW/SSB
p.V
0.25 1.0
2.
Sensitivity for 10 dB S/N CW/SSB
p.V 0.25 1.0
3. AGC Figure of Merit, 50 mV for 10 dB Change in Audio Output
CW/SSB dB 80 70
4.
Overall Audio Fidelity at 6 dB down
Upper Frequency SSB Hz 3200 2500
rv 3900
Lower Frequency SSB Hz 400 200 rv 500
5. Adjacent Channel Selectivity
(1 0 kHz, 1 GEN) CW/SSB dB 70 60
6. Maximum Audio Output Power CW/SSB w 3.0 2.0
7. Audio Output Power at 1 Oo/o THD CW/SSB w 2.0 1.8
8. RF Gain Control Range CW/SSB dB 55 30 rv 70
9. Squelch Sensitivity at Thresnold CW/SSB
p.V 0.5 2.0
1 0. Squelch Sensitivity at Tight CW/SSB
p.V 1000 250 rv 4000
11 . S Meter Sensitivity
at "S-9" (No Modulation) CW/SSB
PV
100 25 rv 400
12. Image Rejection Ratio CW/SSB dB 65 55
13. IF Rejection Ratio CW/SSB dB 65 55
14. Oscillator Dropout Voltage CW/SSB v 9
11
15. Battery Drain at No Signal CW/SSB rnA 500 800
16. Battery Drain at Max. Audio Output CW/SSB rnA 1000 1500
17. RIT Range CW/SSB kHz ± 1.5 ± 1.0
rv ± 2.0
18. S/N Ratio at input 1mV SSB dB 45 30
19. THD at 500 mW 1 kHz SSB % 2.5 6
cw
% 2.5 6
20. Output Deference 1mV SSB 0 dB Ref. cw
dB 0 ±5
21. Noise Blanker Performance
cw
dB 20 15
SSB dB 20 15
22. RX/TX Frequency Deference
cw
Hz ±50 ±300
SSB Hz
±50 ±300
-4-

23. Phone Output Power
(EXT. out 0.5W)
IF FREQUENCY
1. IF
2. Pass Band SSB/CW
cw
SSB
UNIT NOMINAL
mW
mW 1.25
1.25
10.695 MHz
± 1.1 kHz (-6 dB)
±2.5 kHz (-60 dB)
LIMIT
0.8
'V 2
0.8 'V 2
The receiving signal system is the single conversion type. The local oscillation is at the upper side.
OVERALL PERFORMANCE
1. Output Protection: Shall meet for 5 minutes for all VSWR's (around the Smith Chart) of 5:1
without damage.
2. Output stability of all VSWR;S (around the Smith Chart) of up to 5:1 under continuous opera-
tion of a duty cycle of 5 minutes transmitting, and 1 minute receiving.
3. Standard Operating Temperature: +14°F rv +122°F (-10°C rv + 50°C)
Note: Nominal specs represent the design specs; all units should be able to approximate these- some
will exceed 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 a unit perform to less than any li-
mit spec.
-5-

·· DISASSEMBLY INSTRUCTIONS
TO REMOVE THE TOP AND BOTTOM COVERS
1. Remove 4 mounting screws ® from both sides of the unit.
2. Remove 8 screws @ from both sides of the unit.
3. Pull out the top and bottom case.
TO REMOVE THE FRONT PANEL
1. Remove 4 screws © from both sides of the main chassis.
2. Pull out the volume knob and frequency control knob from the front panel.
3. Pull out the front panel.
-6-

....,
I
S?EAKER
~-.....---~ ~~
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LlOi~o:Mr--
1.\
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-- I I
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----~ ~---------
1 I I I :
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-~
o-
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0"'!
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I I I I
' 'en
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leo
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~=-~ m m~------------------------------HJ
l I l---1 ~WITCHING -
C:502 0501 I I
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TX BY...::-
RX SV ~
C0/'1 8V TO
PLL 8V
I r--- I
I I I
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HUT~ 1---.o"o
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CIRCUIT DESCRIPTION
1. PLL circuit
ThePLLcircuitused in this model consistsoftwo 10kHz and 5kHz reference loops, and in the 5kHz loop
1kHz step is obtained by a 1 /1 0divider. Moreover, by controlling frequencyoftheVCXO(oscillator) with
a microcomputer and a
D/ A converter, 100 Hz step is obtained.
Theory of operation will be given below.
0305 is the reference oscillator (1 0.24 MHz) and supplies the outputto two PLL ICs, IC302 and IC305.
The 0305 is also used asthe RITcircuitwhich variesthe frequency by ±1.5kHz with the varicap (D303)
voltagevaried. ThereferenceoscillatorsignalappliedtoIC302and IC305iscounteddownto 1/2048and
1
/1 024bythe respective dividerandthenfed to phasecomparators. 0302 isaVCOforthe 105MHzband
and the outputenters IC302
in passing through 0301 bufferamplifier. IC302 counts down the inputand
applies the output to the phase comparator.
Thephasecomparatoroutputpassesa loopfilterconsisting of
0303 and 0304 andcontrols 0302 (VCO)
frequency.
fROM
CPU
r
!
"'
6
ori
0301 buffer output is applied to IC303, counted down to 1/1 0, and then applied to IC304 mixer.
0309 is a 22MHzoscillator which usesa VXO (Variable Crystal Oscillator) circuitto obtain a 1OOHz step
operation. The microprocessordevelops 6 bit dataand the dataare converted into a DC voltage by the
IC307, D/ Aconvertercircuit, and the DC voltage is used asacontrolvoltagefortheVXO, thusdeveloping
the
1OOHz step. Theoscillatingfrequencyis 22.0000- 22.0009MHz (1OOHz step). Thesignal isinjected
into the IC306 mixer.
0307 output is also injected to the IC306 and the mixed output passes through a
LPF and injected to IC304 mixer.
The IC304 mixer output passes through the LPF and enters a divider inside IC305 and applied to the
phase comparator with the reference oscillator output.
The phase comparator output passes through IC307 loop filter and controls
0306 (VCO) frequency.
TheVCOoutputpassesthrough
0308 bufferamplifierand BPF(L318, L319)andentersthe RX/TX mixer
as the local output.
Operations shown above can be given as an equation shown below:
F1 = (N2/M2)Fr+fo+f1 = Fr(N2/M2+1 /10 N1 /M1 + fo/fr)
where,
F1 = Local frequency
Fr = Reference oscillator frequency 10.24 MHz
M1 = 2048
M2 = 1024
N2 =10kHz step 500- 669 (step 1)
N1 = 1 kHz step 23390- 23408 (step 2) CW
23393- 23411 (step 2) SSB
to= 0.1 kHz step 22.0000 MHz- 22.00009 MHz
When the 500kHz key is pushed, the microprocessor computes N1, N2, and fo required to step up by
500kHz from a current frequency and transfers the data to the PLL circuit.
-8-

2. Microcomputer peripheral circuits
A 4-bits single chip microcomputer is used with peripheral circuits shown below:
~--~ UC1208
L----L--L....-..----1 CPU
loA ODE OUT(SSB/CN) ----t
STOP
RESET
vee
o Y401
T CLOCK
With the powerturned on the RESETcircuit(IC404, 0402, 0403) operatesand allowsthe microproces-
sor to transfer PLL data and LCD display data to each IC.
A signal from the pulse switch 8613 is waveshaped in IC403 and then applied to the microprocessorto
prevent erroneous count operation.
In thetransmitmode, PTT IN (pin41)goesLowlevelandTXOUT(pin56)goesHi level. Then, 0401 oper-
ates and the unit enters the TX mode.
In the transmit mode, MUTE output (pin 57) goes Hi level and the AF IC is muted. However, in the CW
mode the MUTE output is released, thus outputting the CW monitor sound.
C413 (super capacitor) relates to memory back-up time and holds the memory contents for about 17
months.
Moreover, by connecting a power source to the BATTERYterminal the memory backup will be assured
regardless of power switch of the unit.
The KEY matrix consists of seven switches, 3 rows by 3 columns as shown below.
DOWN UP .. ODE
UC1208
6 9 10
Operation of keys varies voltage level (Hi or Low) on the matrixand with thisvariation respectivefunction
will be actuated (as programmed in the microcomputer). When operating each key, 2kHz beep tone is
generated at pin 27 for 50ms and applied to the AF power amplifier.
-9-

ALIGNMENT PROCEDURE
ALIGNMENT OF P.L.L. AND CARRIER OSCILLATOR PORTION
1. Test Equipment Required
DC Power Supply (13.8 V)
Frequency Counter
Dummy Load (50 ohm)
2. Preparation for Alignment
F-LOCK OFF
TX/RX SW : RX
3. Alignment Procedure
Step Preset to Adjustment
1 Mode: RX, CW
L302
S.S.G.: 29 MHz
2 Same
L303
3 Same L 313
4 S.S.G.: 29.699MHz L 312
Mode: RX, CW
5 Same L
321
-6 Same as step 1.
VR303
7 Same as step 1.
VR302
8 Same as step 1.
VR 301
9 Same as step
4.
L 317
10 Same as step
7.
No alignment
11
Same as step 1. L 321
Oscilloscope
DC Voltmeter
MODESW CW
RIT Middle position
Remarks
Connect a
DC voltmeter to TP 301 .
Adjust L 302 for 4 ±
0.1 V reading on the DC voltmeter.
Connect an oscilloscope to TP 302.
Adjust L 303 for maximum reading on the oscilloscope.
Connect a frequency counter and the oscilloscope to TP 303.
Adjust L 313 for 10.695 MHz ±10 Hz reading on the frequen-
cy counter.
Connect the oscilloscope to TP 307.
Adjust L 312 for maximum reading on the oscilloscope.
Connect the oscilloscope and the frequency counter to TP
307.
Adjust L 321 for 22.0009 MHz ± 10 Hz reading on the fre-
quency counter.
Adjust
VR 303 for 22.0000 MHz ± 10 Hz reading on the fre-
quency counter.
Connect the oscilloscope to TP 305.
Adjust VR 302 to obtain the waveform as shown on the Fig. 1.
Connect the oscilloscope to TP 306.
Adjust VR 301 to obtain the waveform as shown on the Fig. 1.
Connect the DC voltmeter to TP 303.
Adjust L 317 for 5.5 V ± 0.1 V reading on the DC voltmeter.
Connect the DC voltmeter to TP 303.
Check if voltage is more than 3 V at TP 303.
Connect the oscilloscope and the frequency counter to TP304.
Adjust L 321 for 38.695 MHz ± 20 Hz reading on the frequency
counter.
-10-

3. Alignment Procedure (Cont.)
Step Preset to Adjustment Remarks
Connect the oscilloscope and the frequency counter to TP
12 Mode: TX, CW
VR304
304.
S.S.G.: 29 MHz Adjust
VR 304 for 38.695 MHz ±20 Hz reading on the fre-
quency counter.
Connect the oscilloscope and the frequency counter to TP
Mode: RX, CW 301.
13 No alignmen1 Check if the frequency is 38.695 MHz ±1.0 -±2.0 kHz when
S.S.G.: 29 MHz turn the RIT volume to fully clockwise from fully counterclock-
wise.
4. Test Equipment Connection
P.T.T. Transceiver 501l.Lood
EJITJ
DC Power Supply
13.8V
o Oscilloscope
-11-
Frequency
Counter

ALIGNMENT OF TRANSMITTER PORTION
1. Test Equipment Required
DC Power Supply (13.8 V) more than 10 A
AF Signal generators (Two required)
RF SSVM
DC Ampere Meter
AF SSVM
Key Switch
2. Preparation for Alignment
Oscilloscope 1, 2
RF Power Meter
Dummy Load (50 ohm and 8 ohm)
VR 5, 6 Counterclockwise
VR 11 Counterclockwise
VR 12 Clockwise
TX/RXSW RX
FREQUENCY : 29.000 MHz
3. Alignment Procedure
Step Preset to Adjustment Remarks
Mode: SSB Remove the
B001 (PB-1 00) from Main PCB.
1 No modulation
VR12 Connect a DC Ampere meter(+) to TP 6, (-)to TP 5.
Adjust VR 11 for 50 rnA reading on the DC Ampere meter.
2 Same
VR 11
Connect the DC Ampere meter(+) to TP 6, (-)to TP 4.
Adjust VR 12 for 50 rnA reading on the DC Ampere Meter.
Disconnect the
DC Ampere meter. Reinstall the B001 to the
Main PCB.
OSC
1:500 Hz Connect a RF Power meter to the Antenna jack and then, con-
3 OSC
2: 2400 Hz
L26
nect a RF SSVM, an oscilloscope across a RF dummy load to
S1, S2: ON the RF power meter.
Mode:SSB Adjust L 26 for maximum reading on the RF SSVM.
During this step, set the AF S.G. so that the output is less than
20 Vp-p. Repeat this step two times.
Adjust level of OSC 1 and OSC 2 for 30 mV reading on the AF
4 Same
VR5
SSVM, then adjust VR 5 for 36 Vp-p reading on the oscillo-
scope.
Pull RF Gain Adjust level of OSC 1 and OSC 2 for 30 mV reading on the AF
5 Control
VR6
SSVM, then adjust VR 6 for 16 Vp-p reading on the oscillo-
(Low Power) scope.
6 osc
1, osc 2:
VR4
Adjust VR 4 so that the carrier leakage at SSB and CW be-
OFF come minimum and almost equal.
7 Same as step 3. VR9
Adjust level of OSC 1 and OSC 2 for 30 mV reading on the AF
SSVM, then adjust VR 9 so that "9" LED just lights on.
Mode: CW Connect
an AF SSVM across a dummy load (8 ohm) to EXT
8 No modulation
VR13 jack. Connect a key switch to the Key jack. With Key switch
ON, adjust VR 13 for 0.2 V reading on the AF SSVM.
-12-

Step Preset to Adjustment Remarks
9 Mode: CW No Check if the RF power level is 23 rv 29 W reading on the RF
KEYSW: ON alignment power meter.
Mode: CW
10 (Low Power) No Check if the RF power level is 3 rv 7 W reading on the RF
Pull RF Gain Con- alignment power meter.
trol
4. TEST EQUIPMENT CONNECTION
CW KEY SW
~
SSVM
Osc i lloscope
+TP6
DC
0 0 000
Oscilloscope Spectrum
Analyz e r
Connection for Transmitter Alignment
MIC PLUG
-13-
TX SW
::----c/o
: AFOSC(+)
AFOSC(-)

ALIGNMENT OF RECEIVER PORTION
1. Test Equipment Required
AF SSVM
Oscilloscope
Standard Signal Generator (29.000 MHz,
and 50 ohm Impedance)
DC Power Supply (13.8 V)
Dummy Load (8 ohm)
Noise Generator
2. Preparation for Alignment
NB SW OFF
Min.
MAX
MODESW
RF Gain
TX/RXSW
SSB
MAX
RX
Squelch
VOLUME
RIT Middle position
3. Alignment Procedure
Step Preset to Adjustment
1
L2rvL5
L 7 and L 8
2 Squelch: Fully
VR2
clockwise
3
VR 1
4 NB:ON
L 1
TEST EQUIPMENT CONNECTION
.,a
Signal 00
Generator
D
Oscillo-
scope
Remarks
Alignment for sensitivity
Adjust coils for maximum reading on the AF SSVM.
(During this step, set the Standard Signal Generator attenuator
so that the standard output is less than 0.5 W (2
V/8 ohm).)
Alignment for Squelch
Set the output of Standard Signal Generator to 1 mV and
squelch to maximum.
Adjust VR 2 so that the squelch just breaks.
Alignment for S-Meter
Set the output of Standard Signal Generator to 100 f.J.V, no
modulation.
Adjust VR 1 so that "9" LED just lights on.
Set the level of S.S.G. to approx. 2p,V, then adjust L1 for maxi-
mum reading on the oscilloscope.
Connect the oscilloscope to TP 1.
Transceiver
~----, EJ ~
EXT
SPKR
1~11--1'1
DC Power Supply
13 .8V
-14-
---, AF Oscillo-
1 I SSVM
1 1
scope
I I ...__---t-1--'
I I f '
1 I I 1 I I
1 L ___ J L ___ _J L-
L--------------
a.n.
Load

ALIGNMENT POINT LOCATIONS
Main PCB
VR6 VR5 VR9
LOW POWERO 0 ORFMEr:
6
HI POWER
00
SQ S METER
PLL PCB
r-------------,
: DL
317
: t1TP303I
I I
I I
I I
I I
: VR303
L_ ______________ j 0
L8
D
liH
L12 Ll3 T
LJLJ
iITP306l
TP4 0 TP5
DDVRII D
~
Ll
D
L7
D
1ITP304l L303
D
f L304 t 0
D 0 ITP302l TX FREO.
VR304
ITP306l
VR302 L
312
.--ITP-~----11 0 D
L321
D
BALANCE I
VR301 BLANCE 2
-15-
PB130AA
D
VR12
L26
0
OVR4
CARRER
BALANCE
PBI33AA
ITP3011
i

TROUBLESHOOTING HINTS
Note: Refer to the transistor voltage chart and the IC voltage chart for the IC and transistor terminal vol-
tages.
TRANSMITTER SECTION
No
transmission.
'
NG
Replace defective
Check PTT
switch.
PTT switch.
f OK
NG
Replace
defective
Check microphone.
parts.
f OK
Check
microphone
NG
Replace defective
jack. parts.
f OK
Check microprocessor circuit. *
See
microprocessor
section.
l OK
Check
pins
7 and
8 of IC3
NG
Replace defective parts.
f OK
Check voltage of
031,
NG
Replace defective parts.
029 and 027.
f OK
Check
voltage and
* See PLL
section.
frequency at TP2.
l OK
NG
Replace antenna
and
Check antenna.
antenna jack.
f OK
Check antenna wire.
NG
I I
Resolder W511.
f OK
I I
Check voltage of 0502,
NG
05.0 1, 033 and 034.
Replace defective parts.
f OK
Check
voltage of
IC6, IC2,
NG
..
Replace defective parts .
IC3.
f OK
Check
voltage and
NG
Check
voltage of
NG
Replace
defective
frequency at TP3.
023.
parts.
! OK
NG
I I
Check
voltage of
024 and 025.
I Replace
defective parts.
t OK
Tx section is not defective.
-16-

RECEIVER SECTION
I No reception. I
OK
Check the speaker and
the wire connection.
OK
Check voltage at
pin7 of IC5.
NG
NG
Replace defective parts
and/ or poor soldering.
Check voltage at
base of 039.
i OK
NG
.
OK
* See microprocessor section.
Check voltage at pin1
of IC5.
OK
Check voltage of 027,
031.
OK
Check if the SO
control operates
normally.
OK
NG
NG
NG
.
Replace defective parts.
Replace defective parts .
Check voltage at
pin5 of IC1.
NG
Check if the voltage level is 1Vp-p · NG
and frequency is 10.695MHz (CW) Check
voltage of
023.
and 10.6965MHz (SSB) at TP3. ·
OK
NG
NG
Replace defective
parts.
Replace
defective
parts and/ or readjust
sa control.
Replace defective
crystal (X1 ).
Check voltage of 0 13 ....... 18 . I Replace defective parts.
II
OK
Rx section is not defective.
-17-

PLL SECTION
' No good.
Check if the
LCD
displays
NG
microprocessor section check.
normally. *
See
OK
frequency is
Check if the
NG
Replace defective 0305
10.24MHz at
emitter of
and/or
X301.
0305.
OK
Check if the voltage is
Check if the
NG
NG NG
0.4Vp-p and frequency is Check. voltage Replace
voltage is
GV
~
10.4965MHz (SSB) and
__..
~
at TP301. 10.495MHz (CW)
at
of 0301-304.
defective parts.
TP302. J
OK +OK
Check voltage
of IC303,
NG
OK
IC302. Replace defective parts.
OK
,,
Check voltage
of IC305.
NG
Replace defective parts.
OK
Check if the voltage
NG
Check if the voltage
NG NG
Replace
of TP303 is 5.5V at
_..
is 120mVp-p and
___..
Check voltage
~
defective 0309
29.6999MHz and 3V frequency is 22MHz
of 0309.
at 28.000MHz. at TP307.
and/ or X302.
OK
I
OK
+
,
Check if the voltage is
NG
Check voltage
NG
Replace
120mVp-p and frequency is
of IC306 and defective parts.
17.6965MHz
at TP305.
0306, 0307.
OK
+OK
NG
Check voltage of 0307.
. Replace defective parts.
OK
I
,,
Check if the frequency is
NG NG
28.000MHz""29.6999MHz.
~
Check voltage
of
0308.
~
Replace defective parts.
• OK
OK
ICheck
if connection of J301 is OK.
Replace defective L318
and/or L319. I
• OK
PLL section is not defective.
-18-

MICROPROCESSOR SECTION
No good.
Check if the
LCD displays
normally.
NG
_____.
Check if the clock
is 2MHz
at pins
44 and 45 of
IC401.
OK
NG
_____.
Check if the
waveform is
as
following figure
at pin43 of
NG
IC402, when
f-+-
power switch
is on.
I
I
JLE
I
I
on_..l
~1mS
OK
Check waveform at ~ Replace
pins 1 and 52
of IC40 1. defactive R404.
OK
Check waveform of I N~
Replace
defective IC402.
pins 6 ....... 13 of IC401. (
~----------~------- ~------------~
OK
Replace defective LCD.
Check if S613 operates
NG NG
normally.
_......
Check voltage of
IC403.
_____.
• OK
OK
Replace defective S613.
NG .
Check
if S605 ....... S612 Replace defective
operate normally.
~
Switch (e).
OK
Check
if PTT operates
NG
Check voltage at
pin41
NG
normally.
~
of IC402.
~
~OK
OK
NG
Check voltage
of
0401.
~
Check the
NG
Replace
output of Mute
and the output
_____.
defective
of BEEP.
IC402.
OK
Microprocessor section is not defective.
-19-
Check NG Replace
voltage
~ defective
of IC404. parts.
Check
voltage
NG Replace
qf
0402
• ~ defective
0403. parts.
Replace
defective Y
40 1.
Replace defective IC403.
Replace defective S603
and/ or Mic. Jack.
Check voltage
at pin56 of
IC402. t
NG
Replace defective IC402.