Giga-tronics 8003, Руководство по эксплуатации

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8003 Precision Scalar Analyzer
2-24 Manual 20791, Rev. C, June 2001
2.5.3 DISPLAY Key
[
DISPLAY]
The FUNCTION
[DISPLAY]
key controls the display and formatting of all of the measurements that
are taken. When
[DISPLAY]
is pressed, the softkey menu will be displayed as shown in F3 in
Figure 2-7 on page 2-26.
[
AVG]
Menu F3: Accesses the averaging sub-menu and allows the averaging factor for the entry channel
to be changed.
Averaging reduces the amount of noise on a trace. The minimum amount of averaging should be
selected to reduce noise to an acceptable level. This allows the trace to change while still control-
ling the noise.
When averaging is selected on a channel, it is indicated by the character
A
, which appears on the
second line of the channel summary area of the CRT display.
[ AVG N]
Menu F3-1: Selects the Averaging Mode and sets the averaging factor for the entry channel.
In the swept mode, the averaging function averages successive traces. The number of traces to
be averaged can either be selected with the spin knob or entered through the numeric keypad.
If entered through the keypad, the selected averaging number will always be rounded to the
nearest allowable number. The allowable averaging numbers are: 1, 2, 4, 8, 16, 32, 64, 128, and
256 traces. In the CW mode, averaging works exactly the same way except that successive CW
power readings instead of traces are averaged.
[
AVG ON/OFF]
Menu F3-1: Initiates or stops averaging on the entry channel. When averaging is off, it is the
same as if averaging were active with an averaging value of 1. Each measured trace will be dis-
played. This feature is particularly useful when it is desired to adjust a device under test (DUT)
while getting the fastest feedback possible, but an averaging factor has already been entered in
the instrument to use for final test. In this case, it is not necessary to have to remember the
averaging factor and change it back and forth from 1 to the final test value. Instead, the averag-
ing capability can just be turned on and off.
[ SMOOTHING]
Menu F3-1 : Smoothing filters a channel trace by performing a moving average on the data
over a specified percentage of the sweep span. The parameter that specifies the percentage of
the channel trace to be averaged for each data point is called the Smoothing Aperture.
Smoothing reduces ripple in the trace. Smoothing is not the best choice for reducing noise. In
the presence of noisy signals, averaging should be used. When both smoothing and averaging
are used, the 8003 first averages consecutive unsmoothed traces then smooths each resulting
averaged trace.