HP Cable Box 8591C manual Marker +CF, Demodulation of an FM Signal

Making Measurements Using Spectrum Analyzer Mode

Demodulating and listening to an AM or FM Signal

‘4u									MKR	104 95	MHz
REF	48.8	dBmV		AT	10 dB					14.31	dBmV
PEAK	1	I	I	I	I	I	I	I	I	I	1

n

p

START 88.00	MHz		STOP 108.00	MHz
RES BW	100 kHZ	VBW 30 kHZ	SWP 75.0	mse

Figure 5-11. Demodulation of an FM Signal

Example: The signal can be continuously demodulated if the spectrum analyzer is in zero span.

1.Place the marker on a signal of interest as in steps 1 through 3 of the previous example.

2.If the signal of interest is the highest-amplitude on-screen signal, set the frequency of the signal to center frequency by pressing (-1 then

MK TRACK ON OFF (ON). If it is not the highest-amplitude on-screen signal, move the signal to center screen by pressing [ml and

MARKER +CF

3.If marker track is on, press ISPAN_) and 1 @ to reduce the span to 1 MHz. If marker track is not used, use the step-down key (a) to reduce

the span and use MARKER --+CF to keep the signal of interest at center screen.

4.Set the span to zero by pressing ZERO SPAN . ZERO SPAN turns off the marker track function.

5-24