HP 8591C, User Manual, Page: 103 / 373

Channel Measurements
Making Channel Measurements
View ingress test
1. Select a channel, then press VIEW INGRESS A marker is placed on the
peak of the carrier, and the delta marker is activated.
2. After the displayed modulation and noise are reduced with minimum hold,
use the knob to position the delta marker on a signal appearing above the
noise. The frequency and amplitude differences between the peak carrier
level and the marker appear in the active function block. See Figure 2-40.
O E C 0 6 , 1 9 9 3
M K R 3 . 0 0 0
36.8 AT - 6 0 . 3 9
:
C E N T E R 1 7 7 . 0 0 0 M H z S P A N 6 . 0 0 8
Y R E S 1 0 0 1 1 8 0
VIEW
CO-CHNL
L I S T E N
A T M K R
R E S
3 0
R E S
MENU
RT
Figure View Ingress
3. During the test, you can change the default 100 resolution bandwidth
(RBW). For example, you might select 30 RES BW to improve
resolution of signals close to the visual carrier. Return to 100 RBW by
selecting 100 RES BW
Selecting either resolution bandwidth resets the minimum hold function
used in the test to improve viewing of ingress.
4. Demodulate the ingress signal in AM or FM by pressing the
LISTEN AT MKR then AM FM Press LISTEN OFF to return to
the previous menu.
5. Press VIEW CD-CHNL to set the analyzer to see co-channel interference.
See Figure 2-41. Also, see Chapter 5 for more information about
VIEW CO-CHNL
2 - 6 0