Electrical Adjustments - Sony TMR-RF915R Servise Manual

TMR-RF915R/RF945R
QQ
3 7 63 1515 0
Setting :
AF signal
generator
L-CH (J402)
Telescopic
antenna
Frequency counter
Transmission Frequency Check
1. Set the noise filter SW to OFF.
2. Input a signal of 1 kHz 40 mVrms to only the L-CH (J402).
3. Connect a telescopic antenna to the frequency counter input
and extend the antenna to a length of approximately 8 cm.
4. Place TX-BASE board close to the frequency counter, then mea-
sure the frequencies of CH1, CH2 and CH3 and make sure the
values are as follows:
CH1 : 913.5 MHz ± 200 kHz
CH2 : 914.0 MHz ± 200 kHz
CH3 : 914.5 MHz ± 200 kHz
TE
L 13942296513
When the frequency is not satisfied the specified value, set the
channel switch (S402) to CH2, then adjust the value of the
frequency counter to 914.0 MHz by trimmer capacitor in the VCO
unit.
Standard value :913.9MHz to 914.1MHz
When completed with replacement, recheck the
frequencies of CH1, CH2 and CH3.
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SECTION 3

ELECTRICAL ADJUSTMENTS

set
TMR-RF915R/RF945R
set
8 cm
TMR-RF915R/RF945R
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Pilot signal Modulation Check and Adjustment
1. Set the channel to CH2.
2. An electric wave is output for 5or 10 minutes when OFF to ON a
power supply (Power indicator will ON).
3. Measure the center terminal of RV403 using an digital volt-meter
(AC range) and make sure the value is 2 to 2.5mVrms.
If the measured value is other than the specified value, adjust to
2 to 2.5mVrms by turning the RV403 on the TX-BASE board.
Connection points and Adjustment Location :
TX-BASE BOARD (Component side)
CH3 ← CH2 ← CH1
S402
RV403
Q Q
3 6 7 1 3
RV403: Modulation adjustment
TX-BASE BOARD (Conductor side)
digtal voltmeter
(AC range)
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.
2 9 9 4 2 8
(L-CH) (R-CH)
J402
VCO UNIT
Hole
1 5 0 5 8 2 9 9 4
Trimmer : Transmission
frequency adjustment
1
2
3
m
co
9 9
2 8 9 9