SONY TMRRF450R
Manual de Servicio

SECTION 2 ELECTRICAL ADJUSTMENTS
Note : 1. The transmitter section adjustments should be completed before performing the headphones section adjustment. 2. On adjusting the transmitter section, use the headphones as a jig. Transmitter TMR-RF450R Setting :
AF signal generator set TMR-RF450R L-CH (J403) telescopic antenna frequency counter 13cm TMR-RF450R set
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Headphones MDR-RF430 MDR-RF450

Sub-Carrier Frequency Check and Adjustment 1. Set the noise filter SW to OFF. 2. Set the channel to CH2. 3. Input a signal of 1kHz 316mVrms to only the L-ch (J403). 4. Connect a frequency counter and an oscilloscope between the Q409 emitter and GND. 5. Set the TX board L-ch (J403) input to OFF (not doing so will cause modulation in the sub-carrier, preventing correct measurement) 6. Check to make sure the frequency counter reading is 48 �52kHz. If the measured value is other than the specified value, adjust the frequency to 50kHz by turning the RV405 on the TX board. In addition, check to make sure the oscilloscope waveform is as follows :

(Perform the check and adjustment within one minute since the transmitter AUTO OFF function will be activated approximately one minute after setting the transmitter L-ch input to OFF. If the AUTO OFF function activates, set the L-ch input to ON, set TX board to AUTO ON, set the L-ch input again to OFF, then make the check adjustment.) Connection points and Adjustment Location : TX board (See page 4)

headphones MDR-RF430 MDR-RF450

Main Carrier Modulation Check and Adjustment 1. Set the channel to CH2. 2. Set the noise filter SW to OFF. 3. Input a signal of 1kHz 316mVrms to only the transmitter Lch (J403). 4. Set headphones VOL (RV301) to MIN. 5. Connect an digital voltmeter (AC range) and oscilloscope between IC301 pin @¡ and GND on RX board (headphones). 6. Receive signals by turning headphones TUNING VOL (RV302). 7. First check to make sure that a demodulated waveform of 1kHz is outputted to the oscilloscope, then check to make sure the digital voltmeter (AC range) reading is AC 12 �15mVrms. If the reading is not within the specified range, turn RV404 on the TX board so that the reading is 13.5mVrms.

battery terminal (DC 3V)

Send Frequency Check and Adjustment 1. Set the noise filter SW to OFF. 2. Input a signal of 1kHz 40mVrms to only the L-ch (J403). 3. Connect a telescopic antenna to the frequency counter input and extend the antenna to a length of approximately 13cm. 4. Place TX board close to the frequency counter, then measure the frequencies of CH1, CH2 and CH3 and make sure the values are as follows: CH1 : 433.3 � 433.5MHz CH2 : 433.8 � 434.0MHz CH3 : 434.3 � 434.5MHz If the measured values are other than the values specified above, adjust the frequencies by turning RV402 and RV403 on the TX board. When completed with adjustment, recheck the frequencies of CH1, CH2 and CH3. Connection points and Adjustment Location : TX board (See page 4)

HEADPHONES
[ RX BOARD ] (Conductor side)

digital voltmeter (AC range)

oscilloscope

Sub-Carrier (L-R) Modulation Check and Adjustment 1. Set the noise filter SW to OFF. 2. Set the channel to CH2. 3. Input a signal of 1kHz 316mVrms to only the L-ch (J403). 4. Measure the pin 1 voltage of the TX board IC403 using an digital voltmeter (AC range) and make sure the value is 220 � 250mVrms. If the measured value is other than the specified value, adjust to 235mVrms by turning the RV401 on the TX board. Connection points and Adjustment Location : TX board (See page 4)

Connection points and Adjustment Location : TX board (See page 4)

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