Specifications

Chapter 14 123
Demodulating and Viewing Television Signals (ESA-E Series Option B7B)
Demodulating and Viewing Television Signals
Demodulating and Viewing
Television Signals (ESA-E Series
Option B7B)
When viewing the spectrum, for analog TV channels, there should be a
strong, “noise-like” video carrier at the center frequency, a weaker,
“noise-like” chrominance sub-carrier located 3.58 MHz (NTSC
standard) or 4.3 to 4.4 MHz (PAL or SECAM standards) above the video
carrier, and a tightly-grouped sound carrier located 4.5 to 6.5 MHz
above the video carrier. If you are viewing broadcast or cable TV
signals, the lower adjacent channel sound carrier may be very close to
the video carrier at the center frequency.
Step 6. Change the RBW to 3 MHz:
Press
BW/Avg, Res BW, 3, MHz.
If the test signal does not have adjacent channels present, change the
resolution bandwidth to 5 MHz. If strong adjacent channel signals are
present (primarily the sound carrier of the lower adjacent channel), set
the RBW to 1 MHz.
Step 7. Set the amplitude scale type of the analyzer to linear:
Press
AMPLITUDE Y Scale, Scale Type (Lin).
Step 8. Set the detector mode of the analyzer to sample:
Press
Det/Demod, Detector, Sample.
Step 9. Set the analyzer in time-domain span:
Press
SPAN X Scale, Zero Span.
Step 10. Adjust the reference level so that the signal peaks are within half of a
division of the top of the display.
Press
AMPLITUDE Y Scale, then use the knob or arrow keys.
Step 11. Set up the TV trigger properties:
Press
Trig, TV Trig Setup.
Press
Field, Entire Frame, Sync (Pos) (or Sync (Neg) for SECAM signals.
Press
Standard, then select the appropriate standard for the video
signal.
Press
TV Source, SA.
Step 12. Enable the TV trigger:
Press
Trig, TV.
The default line number for triggering can be changed to any value
from 1 to 525 or from 1 to 625, depending on the selected video
standard.
Step 13. Decrease the sweep time to view several TV lines (if you have option
AYX or B7D):
Press
Sweep, Sweep Time, 500, µs.