Triggering on a Selected Line of a Video Picture Field

You can trigger on a TV picture carrier signal. This example enables you to view a test signal transmitted during vertical retrace when the TV screen is blanked.

1.Press [PRESET].

2.Set the frequency of a picture carrier signal to center frequency.

3.Press (TRIG) and TV TRIG If the spectrum analyzer is in a nonzero span,

TV TRIG sets the amplitude scale to linear, places a marker on the signal peak, moves the marker to the reference level, changes the detector to sample, sets the sweep time to 100 ps, sets the resolution bandwidth

to 1 MHz, and sets the span to 0 Hz. The TV line number is the active function. The preset function sets the spectrum analyzer to trigger on an odd field of a video format and TV line number 17.

The sweep time of 100 ,DS allows you to view two TV lines, line 17 and part of line 18. The multiburst is on TV line number 17, and the composite is on TV line number 18.

fb

MKR 85 000 vsec

 

CENTER 67.250

MHZ

 

SPAN 0

HZ

I

 

 

 

IRE5 BW I

MHz

VBW 300 kHz

#SWP 100

Lsec

 

 

 

 

 

 

 

Figure 5-13. Triggering on an Odd Field of a Video Format

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