ACCEPTANCE TESTING
7-25
AM scale shape
Test procedure
(1) Connect the test equipment as shown in
Fig. 7-8.
(2)
On the UUT set source A to:
[Carr
Freq]
100
[MHz]
[RF
Level]
0
[dB]
[AM] [AM Depth]
1
[%]
[AM
ON/OFF]
(3)
On the modulation meter, select CAL, AM, 300 Hz
Þ
3.4 kHz LF filter.
(4) Measure the AM accuracy at the depths shown in
Table 7-40,
checking that the results are
within specification.
(5)
Repeat (2) to (4) for source B.
External AM frequency response (ALC off, DC coupled)
Test procedure
100 Hz to 30 kHz
(1) Connect the test equipment as shown in
Fig. 7-9.
(2)
On the UUT set source A to:
[Carr
Freq]
400
[MHz]
[RF
Level]
−
4 [dB]
[AM] [AM Depth]
80
[%]
[AM
ON/OFF]
[UTIL]
[Mod’n
Mode]
Press
[Down]
until ‘AM external’ can be selected
[Select Mode] [EXIT]
[SIG
GEN]
[Select Coupling] [Ext DC Coupling] [EXIT]
(3)
Set the function generator to give 1 V RMS, 1 kHz sine wave.
(4)
On the modulation meter, select CAL, AM, 10 Hz
Þ
300 kHz filter.
(5)
On the modulation meter, check that the AM reading is between 76% and 84%, then set a
reference using the relative function. Record the absolute reading for use in the formula in
(17).
(6)
Set the function generator to each of the frequencies shown in Table 7-41 checking that the
relative readings on the modulation meter are within specification.
(7) Set the UUT RF level to +6 dBm and repeat (3) to (6) using
Table 7-42.
(8)
Repeat (2) to (7) for source B.
