Test Equipment
Reference Material
25B1022 (AG)
Measurement Reference
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
Equipment Type
Audio analyzer
Digital multimeter
Rf signal generator
Frequency counter
Spectrum analyzer
Shure U4 receiver
SMC to BNC Adapter
Audio Test Head
Test Head Brass Ring
*Audio levels in dBu are marked as dBm on the HP8903B.
Use the Shure UHF Wireless System User's Guide for information
on Controls, Operation, Specifications, etc. Refer to the appropriate
User's Guide or User's Guide Supplement for information on frequency
compatibility.
13
Shure U2 Hand-Held UHF Transmitter
Table 1
Test Equipment
Model
*Hewlett-Packard 8903B
Fluke 87
Hewlett-Packard 8656B
Hewlett-Packard 53181A
Hewlett-Packard 8590L
Shure U4
PT1838S
PT1840
PT1838Y
Service Procedures