ACCEPTANCE TESTING
7-31
Modulation oscillator distortion and LF output flatness
Test procedure
UUT
INPUT
MOD
I/O
C4673
Audio Analyzer
Fig. 7-15 Modulation oscillator distortion test set-up
(1)
Connect the test equipment as shown in Fig. 7-15.
(2)
On the UUT set source A to:
[MOD ON/OFF]
(To enable modulation source)
[FM Mod Freq]
1
kHz
(3)
Measure the distortion on the audio analyzer checking that the result is within the
specification shown in
Table 7-48.
(4)
Measure the absolute level on the audio analyzer (in dBm) and record this level as a
reference.
(5) Set the UUT mod source to each of the frequencies shown in
Table 7-48
. Subtract the level
measured on the audio analyzer at each frequency from that recorded in (4) checking that
the results are within specification.
(6)
Repeat (2) to (5) for source B.
