Panasonic RF-B20L - Measurements and Adjustments; How to Replace; Dial Threading; Alignment Instruction

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m HOW TO REPLACE
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NOD W
Front Cabinet
Hold Switch
Rear Cabinet
oO
Sens Switch c fi
During installation, simultaneously fit in A and A’.
Fig. 9 During installation, simultaneously fit in B
and B’.
Fig. 10
DIAL THREADING
. Connect the dial drum (RDG 5905Z) to VC1, and then turn it all the way in the direction (counterclockwise) indicated by arrow @)
as shown in Fig. 1.
. Turn VC2 all the way in the direction (clockwise) indicated by arrow @, and then mount the dial drum (RDG 5906Z) in a position
like that shown in Fig. 1.
. Mesh the VC2 dial drum (RDG 5906Z) with the VC1 dial drum (RDG 5905Z) by fitting the H cut parts together first. (Fig. 2)
. Wind the dial cord as shown in Fig. 3.
. Turn the tuning shaft counterclockwise.
. Attach the pointer to the dial cord (Fig. 4), and then slide it downward to the 0 point as shown in Fig. 5.
. Secure in place with locking enamel paint.
|Locking Enamel |
L— Point. — — J
Fig. 4
MEASUREMENTS AND ADJUSTMENTS
@ ALIGNMENT INSTRUCTION
READ CAREFULLY BEFORE ATTEMPTING ALIGNMENT
1. Set volume control to maximum. 6. Set power source voltage to 4.5 VDC.
2. Set tone control to high. 7. Output of signal generator should be no higher
3. Set band switch to LW, MW, SW1~6 or FM. than necessary to obtain an output reading.
4. Set hold switch to OFF.
5. Set sens switch to DX.
mg LW, MW, SW1~6 ALIGNMENT
SWE I roa ag RADIO DIAL (ELECTRONICS
EP GEN
BAND SETTING VOLTMETER | ADJUSTMENT
CONNECTIONS |FREQUENCY or SCOPE)
AM-IF ALIGNMENT
T2 (AM IFT)
LW-RF ALIGNMENT
136kH
Tuning
capacitor
L20
(LW
OSC
Adjust
for
maximum
5
fully
closed.
Coil)
output.
Tuning
capacitor
CT1-1
(LW
L7 (LW Adjust for maximum
’
(*
1)
output.
Adjust
L7
b
150kHz
Tune
to
signal.
ANT
Coil)
|
moving
coil
Bobbin’
along ferrite core.
et Adjust for maximum
285 kHz : =
output.
ANT Trimmer) | Repeat steps
P
:
Output
meter
.
F
Tuning capacitor : L19 (MW OSC Adjust for maximum
fully closed. ACIOSS VOICE Coil) output.
CT2-1 (MW F
(2)(5).
coil.
Tuning capacitor ”
beaut fully open. Lot 4 OSC Trimmer)
je ) Le (MW Adjust for eae
: (#1 output. Adjust L6 by
550kHz | Tune to signal. ANT Coil) | moving coil bobbin
along ferrite core.
Adjust for maximum
1,500 kHz
CT2-2 (MW output.
(* 1) Cement antenna bobbin with wax after completing alignment.
ANT Trimmer) | Repeat steps
SW1~6 2nd LOCAL OSC ALIGNMENT
(6)~(9).
—
Tuning capacitor L21 (SW1~6 Adjust for maximum
fully closed. OSC Coil) output.
REMARKS
Fashion loop of
several turns of
wire and radiate
signal into loop of
receiver.
Output meter
across voice
coil.
Point of non-
interference. (on/
about 600kHz)
Adjust for maximum
(1) MW output.
LW
=
OS)
LS
(3) LW
LW
2
= =
=
>
—
Fashion loop of
several turns of
S
= =
gS
= =
wire and radiate
signal into loop of
receiver.
511kHz
=
=
=
Ss
= =
Connect to test
point YW through
ceramic capacitor
(10)| SW3 (6 pF). Negative
side to test point
10.975 MHz
Adjust for maximum
(* 2)CT8 (SW1~6] output.
OSC Trimmer) | Repeat steps
(10) and (11).
Tuning capacitor
fully open.
(11)}
SW3
10.425
MHz
(* 2) If the frequency can not adjust ‘10.425 MHz+5kHz”’ please re-adjust it by CT1-3 (SW1~6 OSC).
SW1~6 1st IF ALIGNMENT
11.800 MHz F Output meter *3 ; F
Ww.
a
Point
of
non-
:
(*3)
T4
Adjust
for
maximum
-
|
ot
“at
400Fe.
|
interference.
pt
(SW1~6
IFT)
|
output.
(*3) After alignment, please confirm the oscillate frequency of T4 IFT. The reading should be figure below.
SW1: Ea am SW5: 26.050 MHz+1.5 kHz FREQUENCY COUNTER
SW2: 17.900 MHz+1.5kHz SW6: 28.425 MHz+1.5 kHz 4 +
SW3:
20.400
MHz+1.5
kHz
Input
sens:
Less
than
100mV
SW4: 22.550
MHz+1.5kHz
y
a
Vv
Be
sure
to
fold
at
the
(W)
mark
so
that
mark
is
on
the
outside.