– 6 –
3-2.
Degree of Modulation of Main Carrier (L + R) Check and Adjustment
Preparation:
Procedure:
1. Set the channel of the transmitter to CH2.
2. Turn OFF the noise filter switch on the transmitter.
3. Enter 1 kHz 316 mVrms signal only to the Lch on the transmitter.
4. Set the volume control (RV301) on the RX-BASE board to the minimum position.
5. Connect an AC voltmeter and an oscilloscope between IC 301 pin
@¡
and ground on the RX-BASE board.
6. Rotating the tuning control (RV302) on the RX-BASE board, receive signals.
7. After confirming that demodulated 1 kHz waveform appears on the oscilloscope, check that the AC voltmeter indicates 12 mVrms to
15 mVrms.
8. If out of the specified value, rotate RV404 on the TX-BASE board in the transmitter (TMR-RF930) so as to attain 13.5 mVrms.
Adjustment Location: TX-BASE board in the transmitter (TMR-RF930) (See page 8.)
AF OSC
ATT
AUDIO IN (Lch)
1 kHz 316 mVrms
600
Ω
Trans-
mitter
Head-
phones
+
–
+
–
TMR-RF930
MDR-RF930
+
–
+
–
oscilloscope
AC voltmeter
[RX-BASE board] – Conductor Side –
