Tektronix RTX130B, Service Manual

Page: 83 / 180

Performance Verification
RTX130B QAM & VSB RF Signal Generator Service Manual
3-33
15. Verify that the measurement values are as follows (wait few minutes until the
values become stable):
EVM (QAM A/B/C): < 2.7%
EVM (8 VSB): < 4.5%
16.
Change
RF Center Frequency
to
450 MHz
on the RTX130B.
a.
Select
QAM/VSB
>
Modulation
to open the
Modulation
dialog box.
b. In the dialog box, set the RF Center Frequency to 45 0 MHz .
c. Select the OK button.
d. Press the Play/Pause button to output the RF signal.
17. Change Tuner Frequency in the Input Card dialog box to 450 MHz on the
MPEG transport stream monitor.
18. When the status icon in the Tests screen have all turned yellow or green
(except for disabled or not applicable tests), right click the
Transport
Stream Available status icon, and then select Reset . Within a minute, all
status icons turn green.
19. Repeat steps 14 and 15.
20.
Repeat steps 16 through 19 for the frequency of 750 MHz.
21. Disconnect the 75
Ω
BNC cable from the RTX130B.