Multitone BSR 113, Техническое руководство, Страница: 39 / 63

SIGNAL
RF O/P
PSU
12V
BSR 113
SINAD METER
and
OSCILLOSCOPE
BNC
CABLE
SK7
MOD I/P
1kHz from SINAD METER
SK3
GENERATOR
TAG/10924/1
SK5-2
SK5-1
BSR 113
TM1194A Issue B Page 5 - 5
Figure 1: Receiver and Noise Squelch Alignment Test Equipment
Receiver and Noise Squelch Alignment
9. To carry out the receiver alignment procedure configure the equipment as shown
in Figure 1 and proceed as follows:
a) Connect the oscilloscope (using a DC coupled x1 probe) and the SINAD meter,
across internal test socket SK5 Pins 2 (Audio X) and 1 (GND).
b) Set the signal generator to a signal of +13dBm at the on-channel frequency
modulated with 1kHz at a deviation of 3kHz.
NOTE: If the SINAD meter is used for generating the external 1kHz, set the
correct level into the signal generator by turning the MOD ALC
(modulation automatic level control) on and then adjusting the level
from the SINAD meter until 3kHz FM is indicated rather than Hi or
Lo.
c) Connect the signal generator to the antenna socket SK7.
d) Adjust C3 until the recovered audio on the oscilloscope is at a DC level of
0.62V.
e) Decrease the RF level from the signal generator to achieve 12dB SINAD.
f) Adjust C9 for best SINAD and then reduce the RF level from the signal
generator to maintain about 12dB SINAD.