Yaesu FT-208R, Руководство по техническому обслуживанию

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SERVICING
F.
I .
TX
Frequency Adjustment
Set the transceiver to 146.000
MHz
( 1 4 5.000
MHz).
2. Connect a frequency counter to the secondary
of
T 210
, and adjust the core of
T 20s
for a
reading of exactly 1 46
MHz
( 1 45
MHz).
II. Receiver Alignment
A. 1 st, 2nd IF Alignment
1 . Connect a signal generator to the ANT con­
nector, and set the frequency to 1 46
MHz
( 1 45
MHz)
with 1
kHz
modulation @± 3 . 5
kHz
deviation, and the output level to 20 dB (ref:
0 dB
=
1
µ
V). Connect an oscilloscope to the
earphone jack as shown in Figure 1 .
Figure 1
OSCILLO­
SCOPE
2. Adjust the cores of
T105 , T106
and
T101
until
a minimum distortion pattern and maximum
output are observed on the oscilloscope.
B. RF Coil Adjustment
1 . Set the transceiver frequency and signal
generator to 1 4 7.995 MHz ( 1 45.975 MHz or
1 47.975 MHz), and adjust
T101 , T102 , T103
and
T104
for minimum distortion and maxi­
mum amplitude on the oscilloscope. Now, set
the transceiver frequency to 1 44. 000
MHz,
and again adjust
T101
through
T104 .
Repeat
this alignment at both lower and upper band
edges until maximum sensitivity is obtained
on both band edges.
103 , 104
TI 0 7
T202
T207
FT-208R
ALIGNMENT POINTS
VR2C2 T204
3-20