HP 8590 E-Series User Manual page 283

accesses a menu available for your use for user-defined programs and key
User
functions.
Menus
Front-Panel Key Access: (-3
V changes the amplitude units to V for the
Front-Panel Key Access: (AMPLITUDE]
selects the ratio between the video and resolution bandwidths. If signal
responses near the noise level are visually masked by the noise, the ratio can
RATIO
be set to less than 1 to smooth this noise. The knob and step keys change the
ratio in a 1, 3, 10 sequence. Pressing (PRESET] and AUTO ALL sets the ratio to
0.300 X. The ratio can be changed using the step keys or the knob.
Front-Panel Key Access: m
All E-Series and L-Series spectrum analyzers except HP 85901, with
VERIFY
allows the time base digital-to-analog converter to be changed to verify that
the 10 Mhz reference time base performs to specification. Pressing (-1
resets the time base to its original value. A pass code is required to access this
function.
Note
The VERIFY
spectrum analyzers with Option 004.
Front-Panel Key Access: ICAL)
initiates a digital averaging routine that averages displayed signals and noise.
VID AVG
This function does not affect the sweep time, bandwidth, or other analog
ON OFF
characteristics of the spectrum analyzer. Annotation on the left side of the
screen indicates the current number of sweeps averaged. The default number
of sweeps is 100. Increasing the number of sweeps smoothes the trace. To
turn off the video averaging function, press VID AVG ON OFF so that OFF is
underlined. The number of sweeps can be entered using the numeric keypad.
Front-Panel Key Access: Isw), (ml, or (j-1
changes the spectrum analyzer post-detection filter from 30 Hz to 3 MHz in a 1,
VID BW
3, 10 sequence. For Option 130 only. Option 130 provides additional narrow
AUTO MAN
resolution bandwidths of 30 Hz, 100 Hz, and 300 Hz.
As the video bandwidth is decreased, the sweep time is increased to maintain
amplitude calibration. A "#" mark appears next to VBW on the bottom of the
spectrum analyzer display to indicate that it is not coupled. To couple the
video bandwidth, press VID BW AUTO MAN so that AUTO is underlined.
The video bandwidth can be changed by using the step keys, the knob, or the
numeric keypad.
Note
Coupling the video bandwidth function also couples the video bandwidth to
resolution bandwidth ratio function. If you want to auto-couple the video
bandwidth to a nonstandard ratio, you must set the video bandwidth to
auto-couple before setting the video-bandwidth/resolution-bandwidth ratio.
Front-Panel Key Access:
7-90 Key Descriptions
current setting (log or linear).
or Isw)