Matsushita Electric NATIONAL PANASONIC R-238W User manual

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NATIONAL
anua
•
erv1ce
RAD ID
PANASONIC
"
AM 2-BAND PORTABLE RADIO
MODEL R-238W / R·238R
• SPECIFICATIONS
• SERVICING PROCEDURES
(Printed resistor circ uit )
1. When repairing the chassis .conn ect DC pow er source (4.5V)
to E
XT power jack and speaker to earphone jack too.
2. Th is is a high rel iability pr int ed resistor board.
Spec
ia l care should be exercised when using this resistor
board to
ass ure that the va l ues of the resistors are adequate.
and will
not be damaged w he n used in the circuit.
A) Operation notes:
1. Don't f le x the printed board exc ess ive, ly.
2. Be careful not to damage the printed resistors (black).
conductive paint or feed-through eyel.ets.
3. Avoid applying unnecessary amounts of heat to the
printed resistors. conductive paint or especially to the
f
P.e d-through eyelets.
B) How to check the resistance values
of the p ri nted re -
sistors:
Cut the printed
conductor of the reverse side of the printed
re sistor required to be checked so that the resistor will be
completely isolated.
Then. check the resistance value in the normal manner.
C)
How to replace a printed resistor:
When a printed resistor becomes faulty,
cut out that re-
sistor portion and solder a normal resistor to the printed
conductor on the back of the circuit.
Frequency Hange:
MW 525,....,1605 kHz (571,....,187 m)
SW 3.9,....,12.0
MHz (76. 9,....,25 m) W
Intermediate Frequency: 4.75,....,18.0
MHz (63.2,....,16.7 m): ·R
455 kHz
Se nsitivity:
Po w er Ou tput:
Batteries:
Speaker:
Dimensions:
Weight:
Impedance:
MW 50µV /m for 50 mW Output
SW 7 µV for 50 mW Output
700 mW Max imum
4.5V (Three
"D" Size Fl ashlight Bat-
teries)
(NA TIONAL UM-1 or equivalent)
8 cm (
3") PM Dynamic Speaker
203(Wide) x 132(High) x 45(D eep) mm
(
8"x5K'x 1%")
700 g. (1 lb. 8. 7 oz.)
Speaker ........... . ........
.... 8.n
Ea rphone Jack .... ... .......... 8.n
• TO REMOVE CHASSIS
1. Remove a tuning control knob from cabinet.
2. Remove a cabinet back cover screw.
3. Remove a red chassis screw as i l.l ustrated in fig. 1.
4. To rem ove chassis completel y, unsolder t wo l ea dwires to the
printed circuit board.
5. To reassemble. reverse the above procedure.
Note:
When removing the chassis. keep to push the part
of @ direction
of the arrow mark and pull out the part of @direction of the
arrow mark. (
Fi g. 2 & Fig. 3)
®
F
·-· -El 19. 1
@
Fig. 3
· MATSUSHITA
ELECTRIC
II
.-:;,
ORDER NO. RD-890
MATSUSHITA ELECTRIC TRADING CO., LTD .
P. 0. Box 288, Central Osaka. Japan

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Schematic Diagram~ Model R-238W/R-238R
I
I
I
I
I
I
I
I
I
TR 1
2SC829
RF AMP
I ya:
/Sj_ Cf
-"
N
N
Q!
TR 2
2SC829
CONV
01 TR 3
TR < 0 2
1Kl10 2SC828"
2SC829
1Kl10
D.AGC I
sl IF AMP
2nd IF AMP
DET & AGC
I I
I I
L--------- -- - -- - ~ ----- ~ z
c 7 I
R'
2
s
8 3 10
3312 I/
/j/4 J'i/6
20
21
4 2
.s 6 n .jt/.
3 5 7 'I 10
II
12 13
4 30 6
Notes:
1. S 1~S6 : Band se lector sw it ch in " MW" position.
2. S
7: Power so ur ce sw itch in "OFF" position.
3.
Sa: Tone sw it ch in "HIGH" position.
4. Sg: Light sw itch in "ON" positio n.
5. DC volt age measurements are t ake with circ uit t es ter 1 Okn/V from positive
terminal of battery.
6. R es istors are shown by* mark and printed re sistance h as no* ma rk .
7. The currents of TR10 and TR11 s how no signal in the radi o.
TR ,
2SC945
Isl AF AMF
llNT CO IL
22 23
25
3)
24- 32
TR o
2SC945
2nd AF AMP
I H1 u& 1 1 ~ 11
2SC945
INDICA TOR
TR 1
2SC945
3rd AF AMP
SW
s, Sz
MW
S3
~~~6~5
QAB~S~S
Cl4
Ss S&
TR s & TRo
288324
POWER AMP
BOTTOM VIEW
36 28
3031
37
27
29
CJ
SP g.n_
1~ 8on<;'l")
T 1. 2. 3
L3 .4
3004
20
I 0 0 6
14
17 18 !'I 21
20
24
25
2J 2B
29
IS
;c
22 SI 26
- Pos1 l 1v c Voltage L in c - Neqa1 ··<' \:)IJ,1;1,.

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::0
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::0
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IVH IP
ANTE NNA
Circuit Board Wiring View- Model R-238W/R-238R
L1
MWAN TEN NA COIL
TR I
le
EXT I
AN T ENNA
JAC k
TR&
1R1
T i< L L1
TR 2
c - 0.
83 V
8 -3. 3V
E - 3.
9V
l e 0.
5mA
EJ\T PO WER J/\Ck
TU N ING GAN 6
W/ JR IMME R
c
B
l o
0 - 4 . 5 V
8 · O: 14 V
E ov
~
BATTERY 4.5V
TR I I
c
B
- 4. 5V E
l e I 0 .2m A
le
TR 10
- 4 . 5 V
Om A
31 2
Sa T O\IE SW ITCH
EAR PHO N OR
EX T SPE Al<E R
JACk
~ -- --<1/ 1/ r-------- - -------'
TRi
Ls L2 l 4 L3
-Printed Re sistor Conductive Paint
TR 7
c
-0 . 93V
B -
3.25V
E -
3.9 V
le
2.2 mA
Printed Conductor

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N
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0
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R-238W /R-238R
• DIAL CORD INSTALLATION GUIDE
1. Dial co rd leng·h is 10 0 cm (39 %").
2. Turn dial d U"i ·o le ft fully.
3. Arrows
(1 ~ 8) indi ca te correct order and direction of installation dial cord.
4. Ce me n di& ~ ·d end s.
5.. Turn dial ~- -· -,g gang to right fully.
6. Insert he ;::~_~ ~ o . th e dial tuning gang.
•TO MOU T DIAL POINTER
1. Tu rn d· c. :.-_- :: ··ght fully.
2. Se t die : : -:=· :: 5 ~ ar t mark of the d ia l ;:: :.:.·:..
3. Attach :. :o : : ·: :: di al pointer.
• ALIGN ME
STRUCTIONS
Notes:
1. Set vo lurr:o::--: · :- axi mum.
2. Set to ne_ _
3. Set ba n ds===·:· =- ::- :o MW or SW.
4. Set po er s:_·:= : ·=;=to 4.5 volts D C.
5. Output ofs · g-= :=-==·: ·sh ould be no hi ghe·:-= --=== ss ary to obtain
an output ·2=:. -;:
SW AN-
3-2 MHz
CL:;:
SW OSC
12MHz
§]
:_,9~
? £?'?]
MW 1st
455kH7_ -;::;:-
~ E.
MW 2nd
455k Hz -- -
~ 1-":: ~ '3 1
~5~ ~~~ _-: 2
B
MODEL
::
-238W
L
:SA OSC
~ :vH z
~
SWAN T
4.8MHz
cg
0 Pulley
SWA T
18. 0UH z
@;:
MW ANT
1500 kH z
[§]
MWOSC
MW ANT
550kHz
cg
550kH z ~----"
~~
SWOSC'
4.8MHz
cg
MODEL R-238R
R-238W/R-238R

ti TO REMOVE THE SPEAKER
1. Remove the ch ass is from the cabinet.
2. Remove the to ne sw itch.
3. Then remove the speaker.
• CABINET PARTS LOCATIONS
CA3
• PACKING PARTS LOCATIONS
P2
p4
•CAUTION
Do not push dow n the termi na l s. bec au se bad conn ec tions
w ill be happen. (Fig. 4)
RJT378A l
~ Donotpush
L Fig.4
• CHASSIS PARTS LOCATIONS
C Hg
CH 2
CH
a
CH 3
CH1 CH4 CH 1
CH1s
I~~ I -- -~~~······ . -..
··1rf
c~--~-•-C..=~--'.. >,fl
CH6
•ACCESSORY
R-238W /R-238R