Page 1
Note : Follow the disassembly procedure in the numerical order given.
SECTION 1
DISASSEMBLY
Ñ 2 Ñ
1-1. TX BOARD, VCO BLOCK
Cabinet (Upper )
Vco block
7 Remove
solder
7 Remove solder 8 Remove solderTX board
6 TX shield plate
5 TX shield plate
1 Screws +P2 ´ 10Cabinet (Lower)
92
4
3
Page 2
TMR-RF830R
Note :
1. The transmitter section adjustments should be completed before per-
forming the headphones section adjustment.
2. On adjusting the transmitter section, use the headphones as a jig.
SECTION 2
ELECTRICAL ADJUSTMENTS
Ñ 3 ÑÑ 4 Ñ
Send Frequency Check and Adjustment
1. Set the noise filter SW to OFF.
2. Input a signal of 1 kHz 40 mVrms 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 8 cm.
4. Place TX board close to the frequency counter, then measure
the frequencies of CH1 and CH2 and make sure the values are
as follows:
CH1 : 863.27 to 863.37 MHz
CH2 : 863.62 to 863.72 MHz
When the frequency is not satisfied the specified value, first
set the channel switch (S402) to Ò2Ó and adjust CH2 frequency
with L412, next set it to Ò1Ó and adjust CH1 frequency with
L413. When completed with adjustment, recheck the frequecies
of CH1 and CH2.
Main-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 1 kHz 316 Vrms to the L-ch (J403) and the R-
CH.(J402)
4. Measure the pin 2 voltage of the TX board RV 404 using a
digital voltmeter (AC range) and make sure the value is 75 to
95 mVrms. If the measured value is other than the specified
value, adjust to 85mVrms by turning the RV 404 on the TX
board.
Connection points and Adjustment Location :
TX board (See page 4)[TX BOARD] (Component side) 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 1 kHz 316 mVrms to 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 to
250 mVrms. 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)
Sub-Carrier Frequency/Level Check and Adjustment
1. Set the noise filter SW to OFF.
2. Set the channel to CH2.
3. Input a signal of 1 kHz 316 mVrms to only the L-CH (J403).
4. Connect a frequency counter and an oscilloscope between the
pin 2 of RV402 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 mea-
surement)
6. Check to make sure the frequency counter reading is 49 to
51kHz. If the measured value is other than the specified value,
adjust the frequency to 50 kHz by turning the RV405 on the TX
board. In addition, check to make sure the oscilloscope wave-
form is as follows :
HeadphonesMDR-RF830
80 -“ 100mVp-p
134 5
-1
-2
Frequency counter
Oscilloscope
Sub-Carrier
Frequency
Adjustment
RV402
L412 (CH2) L413 (CH1) S401
Noise Filter ON/OFF Switch J402
(R-CH)
RV404 : Main-Carrier (L+R) Modulation Adjustment
RV401 : Sub-Carrier (L-“ R) Modulation Adjustment
RV405 : Sub-Carrier Frequency AdjustmentSend Frequency
Adjustment
J403
(L-CH)
Sub-Carrier Level Adjustment
1
-1 -2
2
CHANNEL Digital voltmeter
(AC range)
Main-Carrier (L+R)
Modulation Adjustment Sub-Carrier (L-R)
Modulation Adjustmen
t Digital voltmeter
(AC range)
TransmitterTMR-RF830R
Setting :
7. When the waveform P-P level is not satisfied the specified value,
adjust to 90mVp-p with RV402.
(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)
AF signal
generator
Telescopic
antenna
8 cm L-CH (J403)
TMR-RF830Rset TMR-RF830Rset
Frequency counter
MDR-RF830 Headphones
Battery terminal (DC 3V)
