Shure U4D Service Manual page 32

Audio Level Setup, Channel B
AUDIO ANALYZER
NOTE: DC VOLTAGES ARE PRESENT
AT MOST RF TEST POINTS. USE A DC
BLOCK ON THE RF SIGNAL GENERATOR
TO PROTECT TEST EQUIPMENT.
For the following test, make sure the tone key switch (S201) is OFF.
Service Procedures
Shure U4D Dual Diversity UHF Receiver
RF SIGNAL GENERATOR
ANTENNA A IN
S201
(OFF)
U207
PIN 7
P202
P203
J302
Figure 15. Channel B Audio Level Setup Connections
All Models (Except II and KK Models)
1. Change the modulating frequency out of the audio analyzer to
1 kHz with deviation set to 45 kHz. If necessary, readjust the
amplitude so that the HI EXT and LO EXT lights turn off.
2. Place the (+) terminal of the audio analyzer on U207, pin 7, and
connect the (–) terminal to ground.
3. Adjust R250 until the audio analyzer reads 0.436 ± 0.005 Vrms.
II Models (Japan)
1. Set the rf signal generator's deviation to 28.0 kHz and the
modulating frequency to 1 kHz.
2. Place the (+) terminal of the audio analyzer on U207, pin 7, and
connect the (–) terminal to ground.
3. Adjust R250 until the audio analyzer reads 0.282 ±. 003 Vrms.
KK Models (United Kingdom)
1. Set the rf signal generator's deviation to 40.0 kHz and the
modulating frequency to 1 kHz.
2. Place the (+) terminal of the audio analyzer on U207, pin 7, and
connect the (–) terminal to ground.
3. Adjust R250 until the audio analyzer reads 0.436 ±. 003 Vrms.
31
DC BLOCK
ANTENNA B IN
S201
(OFF)
R250
P202
P202
P203
P202
25D1062 (AG)