Resolving Signals Of Equal Amplitude - HP 8590 E-Series User Manual

Note
When using an HP 8590L with Option 713 or an HP 8592L with Option 713,
and the signal peak cannot be found, increase the span to 20 MHz by pressing
MK TRACK ON OFF (ON), then ISPAN_) 2 INIHz) to bring the signal to center
screen. Then press MK TRACK Old OFF so that OFF is underlined to turn the
marker track function off.
4. Since the resolution bandwidth must be less than or equal to the frequency separation of
the two signals, a resolution bandwidth of 100 kHz must be used. Change the resolution
bandwidth to 100 kHz by pressing (swl 100 (kHz). Two signals are now visible as in
Figure 3-2. Use the knob or step keys to further reduce the resolution bandwidth and better
resolve the signals.
Figure 3-2. Resolving Signals of Equal Amplitude
As the resolution bandwidth is decreased, resolution of the individual signals is improved and
the sweep time is increased. For fastest measurement times, use the widest possible resolution
bandwidth. Under preset conditions, the resolution bandwidth is "coupled" (or linked) to span.
Since the resolution bandwidth has been changed from the coupled value, a "#" mark appears
next to RES BW in the lower-left corner of the screen, indicating that the resolution bandwidth
is uncoupled. (Also see the
Note
To resolve two signals of equal amplitude with a frequency separation of
200 kHz, the resolution bandwidth must be less than the signal separation, and
resolution of 100 kHz must be used. The next larger filter, 300 kHz, would
exceed the 200 kHz separation and would not resolve the signals.
REF 0 dB"
PEAK
LOG
10
C E N T E R 3 0 0 0 0 0 MHz
key description in Chapter 7.)
S P A N 2 000 MHZ
Making Basic Measurements 3-3