
6-5
A/B Markers
These are two vertical markers on the display. The dotted line is
the active marker; the solid line does not move. This icon
toggles between the two. You can move the active marker with
the arrow keys. The A and B lines below the graph show the
difference (dB) in level (dBmV) between the two selected
frequencies.
2. Freq Sub-Mode
Press this soft key to enter the Frequency sub-menu; and again
to return to the SPECT main menu. The Frequency sub-menu
enables you to select/adjust center frequency, set the Span, and
move A/B cursors as required to evaluate any part of the display.
Center Frequency
Press to select/adjust center frequency. Use the numeric
keypad, then press the
Enter
soft key to place the frequency you
want into the Edit Box that is presented.
Span
Press to select the span of coverage. If any frequency becomes
lower than 5 MHz or higher than 1,000 MHz, then the lowest or
highest center frequency will be used.