6-4
frequency. For use along the return path, with low pass filters
engaged, the spectrum is reduced to 5 MHz to 50 MHz.
There are five sub-menus in SPECT Mode:
Level
,
Frequency,
Amplifier/Low-pass Filter
,
Zero Span
, and
CSO/CTB
. CSO/CTB is
discussed in Chapter 4 in the Measurements Mode sections. The
following describes soft key functions and operation of the other sub-
menus.
1. Level Sub-Menu
Press this to enter the
Level
menu, then to return to the main
menu. Use the
Level
icon soft key to adjust the vertical
parameters of the graph. These parameters include:
Ref Level
The reference level is located at the top line of the 6 x 10 graph.
Adjust Ref Level using the up/down arrow keys, or by entering a
numeric value followed by the
↵
Enter key.
Scale
The scale parameter (1, 2, 5, and 10 dB/div) can be adjusted
only with up/down arrow keys. For example, if the reference
level is set to 0 dB and the sale is set at 10 dB/div the first
horizontal grid line above the center equals -30 dB. Press the
Level soft key to return to the main spectrum analyzer display.
Maximum Hold
The Maximum Hold function ensures that the highest amplitude
at each frequency over multiple sweeps is displayed. If
Maximum Hold is ON, you will see the small Icon at the upper
right corner of the display, darkened. As multiple sweeps occur,
the maximum level trace will change only if new sweep levels
exceed the levels of the current trace. A half-tone trace will show
you the current data when Maximum Hold is enabled.