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Shure U4D Dual Diversity UHF Receiver
29
25D1062 (AG)
Service Procedures
THD Verification and RSSI Adjustment (Channel B)
TP308
R367
U310
P202
P203
P202
S201
ANTENNA A IN
ANTENNA B IN
AUDIO ANALYZER
DC VOLTMETER
P202
P202
P203
S201
RF SIGNAL GENERATOR
DC BLOCK
TP325
NOTE: DC VOLTAGES ARE PRESENT
AT MOST RF TEST POINTS. USE A DC
BLOCK ON THE RF SIGNAL GENERATOR
TO PROTECT TEST EQUIPMENT.
(OFF)
(OFF)
J302
L304 for PCB
34A8507
FL313 for PCB
34A8703
Figure 13.
Channel B RSSI Alignment Connections
1. Change the rf signal generator level to –50 dBm.
2. Measure the total harmonic distortion (THD) at TP308
(U310 pin 7) should be less than 0.5%. If not adjust L304 for
PCB version 34A8507 or adjust FL313 for PCB version 34A8703
to minimize the distortion.
3. Adjust R367 for Vrssi at the wiper (TP325). The Vrssi should be
2.75
±
0.1 Vdc for 34A8507F and earlier PCB versions.The Vrssi
should be 2.3
±
0.1 Vdc for 34A8507G and later versions of the
board and the 34A8703 PCB version.
Summary of Contents for U4D
Page 11: ...Shure U4D Dual Diversity UHF Receiver 10 25D1062 AG Preliminary Tests Audio Rf Board Side 2...
Page 46: ...Shure U4 UHF Diversity Receiver 25D1062 TL 45 U4 Rf Audio Printed Circuit Board Legend Side 1...
Page 47: ...Shure U4 Diversity UHF Receiver 46 25D1062 TL U4 Rf Audio Printed Circuit Board Legend Side 2...