Sony TMR-RF930, Service Manual

Page: 4 / 10

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SECTION 2
ELECTRICAL ADJUSTMENTS
Note:
The adjustments should be performed in the order given.
2-1. Transmission Frequency Check and Adjustment
Preparation:
Procedure:
1. Turn OFF the noise filter switch (S401) on the TX-BASE board.
2. Enter 1 kHz 40 mVrms signal only to the Lch (J403) on the TX-BASE board.
3. Connect a rod antenna to the input of frequency counter, and adjust its length to about 8 cm.
4. Install the set in the vicinity of frequency counter, and check that the frequency on each channel is as specified value.
Specified value:
CH1 913.0 MHz
±
100 kHz
CH2 914.0 MHz
±
100 kHz
CH3 915.0 MHz
±
100 kHz
5. If out of the specified value, adjust the frequency by rotating RV402 and RV403 on the TX-BASE board.
6. After adjustment, recheck the frequency on CH1, CH2, and CH3.
Adjustment Location: TX-BASE board (See page 6.)
2-2. Degree of Modulation of Subcarrier (L – R) Check and Adjustment
Preparation:
AF OSC
ATT
AUDIO IN (J403: Lch)
1 kHz 40 mVrms
600
Ω
Trans-
mitter
+
–
+
–
TMR-RF930
+
–
frequency counter
+
–
AF OSC
ATT
AUDIO IN (J403: Lch)
1 kHz 316 mVrms
600
Ω
Trans-
mitter
+
–
+
–
TMR-RF930
+
–
AC voltmeter
[TX-BASE board] – Conductor Side –