21
LI0083 – Revision 22 June 2017
Preparing the 12AU for Measurements
Cables and Connections
Important.
Before connecting the 12AU to your PC, you should install the USB driver. Refer to
“Installing the USB Driver” on page 18 for instructions.
A typical set-up for testing the loudspeaker of a telephone is shown in Fig. 3 below.
•
The signal for the measurement is generated by a signal generator and fed via a BNC cable to
the power amplifier.
•
The output of the amplifier is taken out as a voltage signal (2-pin LEMO) or a current signal
(BNC) and fed to the test object.
•
The microphone in the coupler can be an externally polarized microphone (connected with
7-pin LEMO), or a prepolarized microphone connected with a BNC cable.
•
The signal picked up by the microphone is fed to the analyzer via a BNC cable.
•
For comparison, these signals can be monitored separately during the measurement.
Connection is via BNC and the monitoring is software-controlled.
Mic OutAmp InAmp Out
Cu
rrent Out
+20dB +30dB +40dB +50dB
Monitor
Microphone Conditioner
Overload
High
Pass
20
0V
olt
CCP
-20dB -10dB 0dB +1
0dB
Overload
AC Coupled Mute
Overload
0dB +20dB
Current
G.R.A.S. Sound & Vibration
Power Module Type 12 AU
Gain
Gain
Gain
Output
0dB +1
0dB
Power On
I
O
Acousti
cTest B
ox
AL0023
G.R.A.S.
Serial No. XXXXXX
PC with
•
12 AU Control Software
•
Hardware for
– signal generation
– data acquisition
– signal analysis
USB
connection
From
microphone
output
To microphone
input
To amplifier input
Acoustic Test Box
AL0023
To loudspeaker in test cradle
Fig. 3.
A set-up for production test a loudspeaker withthe Acoustic Test Box AL0023
