Measurement Reference; Test Equipment - Shure U1 Service Manual

Measurement Reference

Test Equipment

BNC (Female) to 1/4-inch Phone Plug Adapter
25C1021 (BG)
Shure U1/U1L Body-Pack UHF Transmitter
dBu is a measure of voltage, and dBm is a measure of power.
For example, the HP8903 should be labeled dBu instead of dBm
because it is a voltage measurement. These two terms are often used
interchangeably even though they have different meanings.
Audio levels in dBu are marked as dBm on the HP8903.
dB Conversion Chart
0 dBV = 2.2 dBu
0 dBu = 0 dBm, assuming the load = 600 Ω
Most test equipment needed is described in the Shure Wireless
Service Equipment Manual. The following test equipment (or approved
equivalent) is also needed.
Equipment Type
Audio analyzer
Digital multimeter
Interconnect Cable
BNC (Male) Cables (2)
DC Blocker
20 dB Attenuator
BNC to QG Cable
BNC to LEMO Cable
BNC (Female) to SMC (Female) Adapter
BNC (Female) to SMC (Female) Adapter
Test Cable, Japan Version
Adapter, Japan Version
BNC (Male) to RG–174 Cable, unterminated
Frequency counter
Rf signal generator
Spectrum analyzer
Shure U4S receiver
*Audio levels in dBu are marked as dBm on the HP8903B.
Printed Circuit Board Interconnecting Cable
This cable is provided with the standard test equipment and is used
to connect U1 circuit boards that have been removed from the case for
servicing. It is made from two custom Shure printed circuit boards, a four-
inch, 11-wire ribbon cable, and one male (Shure 170A07) and one
female (Shure 170A08) surface-mount connector. Note that the SMC
connectors face in opposite directions.
SMC
Female connector
Figure 4. Printed Circuit Board Interconnecting Cable
Table 1
Test Equipment
*Hewlett-Packard 8903B
Hewlett-Packard 53181A
Hewlett-Packard 8656B
Hewlett-Packard 8590L
SMC
Male
(on back side)
13 Service Procedures
Model
Fluke 87
Shure PT1843
Shure PT1838A
Shure PT1838W
Shure PT1838C
Shure PT1838T
Shure PT1825
Shure PT1878
Shure PT1838S
Shure PT1838S
Shure PT1838–AF
Shure PT1838–AJ
Shure PT1824
Shure U4S
connector