SONY MDRRF450
Manual de Servicio

SECTION 2 ELECTRICAL ADJUSTMENTS
Note : 1. Use transmitter with check and adjustment already completed. 2. Thetransmittersectionadjustmentsshouldbecompletedbefore performingtheheadphonessectionadjustment. 3. On adjusting the headphones section, use the transmitter as a jig. Headphones MDR-RF430 MDR-RF450 Setting : Transmitter TMR-RF450R Separation check and adjustment 1. Set the transmitter channel to CH2. 2. Set the transmitter noise filter SW to OFF . 3. Input a signal of 1kHz 316mVrms to onl y the transmitter L-c h (J403). 4. Connect an digital voltmeter (AC range) and oscilloscope to the L-ch speaker outputs (both sides of MDD01). 5. Receive signals b y turning the TUNING VOL (RV302). 6. Adjust the VOL (RV301) so that the RX boar d L-c h speaker outputs (both sides of MDD01) are 155mVrms. 7. Connect an digital voltmeter (AC range) and oscilloscope to the R-ch speaker outputs (both sides of MDD02) and measure thevoltages. 8. At this time, check to make sure the level separation of L-ch and R-ch speaker outputs is more than 20dB. If the separation is less than 20dB, turn R V303 on the RX boar d so that the R-c h output is minimal, then check to see if the level separation of Lch and R-ch speaker outputs is more than 20dB. 9. Input a signal of 1kHz 316mVrms to onl y the transmitter R-c h (J402). 10. Adjust the VOL (RV301) so that the RX boar d R-c h speaker outputs (both sides of MDD02) are 155mVrms. 11. Connect an digital voltmeter (AC range) and oscilloscope to the L-ch speaker outputs (both sides of MDD01) and measure thevoltages. 12. At this time, check to make sure the level separation of L-ch and R-ch speaker outputs is more than 20dB. Connection points and Adjustment Location : RX board (See page 5)

AF OSC L-CH (J403) 1kHz 316mVrms (�7.8dB) Jig ATT Transmitter 600 � J404 power supply (DC 11V)

1. Feed a signal to jig (transmitter) and connect a power supply to DC IN 9V jack (J404). Receive frequency check and adjustment 1. Set the transmitter channel to CH2. 2. Set the transmitter noise filter SW to OFF . 3. Input a signal of 1kHz 316mVrms to onl y the transmitter L-c h (J403). 4. Placetransmitterandheadphonesatadistanceofmorethan5m apart. 5. Set the VOL (RV301) to MIN. 6. Position RX boar d TUNING VOL (RV302) to the center . 7. Connect a digital voltmeter (DC range) and an oscilloscope between IC301 pin @¡and GND. 8. First check to make sure that a demodulated waveform of 1kHz (appr oximatel y 13mVrms) is outputted to the oscilloscope , then chec k to make sure the DC v oltmeter reading is DC 1�1.2V . 9. If a demodulated waveform of 1kHz is not outputted to the oscilloscope or if the DC level is not within the range specified above, adjust the RX board L301 so that a demodulated waveformof1kHzisoutputtedtotheoscilloscopeandwhilethewaveform is outputted, further fine adjust the L301 so that the DC voltmeter reading is DC 1.1V . 10. Whencompleted,makesuresignalscanbereceivedwhenswitching the transmitter channel to CH1 or CH3 by turning RX board TUNING VOL (RV302). Connection points and Adjustment Location : RX board (See page 5)

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