Sony NTM-30 Service Manual page 7

Sound-sensor nursery monitor
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RECEIVER SECTION
Receiver Sensitivity Adjustment
Setting:
Power switch (S202)
CH switch (S201)
VOLUME control (RV202): mechanical center
FM RF SSG
RX board
Carrier frequency: 49.860 MHz
Output level:
0.5 µ V (–6 dB µ V)
RX board
TP2
at no modulation
Procedure:
Adjust T201 and T202 for a minimum reading on the level meter.
Squelch Adjustment
Setting:
Power switch (S202)
CH switch (S201)
VOLUME control (RV202): mechanical center
FM RF SSG
Carrier frequency: 49.860 MHz
Output level:
0.125 µ V (–18 dB µ V)
at no modulation
Procedure:
Adjust RV201 for the RANGE ALM. indicator (D205) is just lights
up and the buzzer sounds point.
Monitor Level Adjustment
Setting:
Power switch (S202)
CH switch (S201)
VOLUME control (RV202): mechanical center
FM RF SSG
Carrier frequency: 49.860 MHz
Output level:
10 µ V (20 dB µ V)
at 1kHz deviation
Procedure:
1. Adjust RV203 for the MONITOR indicator (D204) is just lights
up point.
2. Set the frequency of the FM RF SSG to 49.830 MHz.
3. Set the CH switch (S201) to A, and verify that the signal can
be received.
4. Set the frequency of the FM RF SSG to 49.890 MHz.
5. Set the CH switch to A, and verify that the signal can be re-
ceived.
: ON
: B
speaker out +
TP1
Set
(receiver)
8 Ω
speaker out –
: VOICE ACT.
: B
RX board
TP1
Set
(receiver)
RX board
TP2
: VOICE ACT.
: B
RX board
TP1
Set
(receiver)
RX board
TP2
Receiver Loading Coil Adjustment
Setting:
Power switch (S202)
CH switch (S201)
VOLUME control (RV202): mechanical center
level meter
FM RF SSG
+
3.5 kHz frequency deviation
by 1000 Hz signal.
Carrier frequency: 49.860 MHz
Output level: as low as possible
Procedure:
Adjust L201 so that the sound from the speaker (SP201) becomes
best.
Adjustment Location:
– RX BOARD (Component Side) –
Monitor Level Adjustment
Receiver Sensitivity
– RX BOARD (Conductor Side) –
Speaker out +
Speaker out –
– 7 –
: ON
: B
loop antenna
RV203
T201
Adjustment
T202
RV201
Squelch Adjustment
TP1
BP3
L201
Receiver Loading Coil
Adjustment
about 400 mm
Set
(receiver)
TP2

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