R&S ESU Series Operating Manual page 165

R&S ESU
HOLD CONT The HOLD CONT ON/OFFsoftkey defines whether the traces in min hold and max
ON | OFF hold mode are reset after some specific parameter changes.
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In general, parameter changes require a restart of the measurement before results
are evaluated (e.g. with markers). For those changes that are known to require a
new measurement (e.g. modification of the span), the trace is automatically reset so
that erroneous evaluations of previous results are avoided.
This mechanism can be switched off for those exceptional cases where the
described behavior is unwelcome.
Remote command:
AVG MODE The AVG MODE softkey selects logarithmic or linear averaging for the logarithmic
level display mode.
At the same time the difference calculation is switched between linear and logarith-
mic in submenu TRACE MATH.
Remote command:
With logarithmic averaging, the dB values of the display voltage are averaged or
substracted from each other with trace mathematical functions. With linear averag-
ing the level values in dB are converted into linear voltages or powers prior to aver-
aging. Voltage or power values are averaged or offset against each other and
reconverted into level values.
For stationary signals the two methods yield the same result.
Logarithmic averaging is recommended if sinewave signals are to be clearly visible
against noise since with this type of averaging noise suppression is improved while
the sinewave signals remain unchanged.
For noise or pseudo-noise signals the positive peak amplitudes are decreased in
logarithmic averaging due the characteristic involved and the negative peak values
are increased relative to the average value. If the distorted amplitude distribution is
averaged, a value is obtained that is smaller than the actual average value. The dif-
ference is -2.5 dB.
4.134
OFF: The traces are reset after some definite parameter changes (default)
ON: This mechanism is switched off.
:DISP:WIND:TRAC:MODE:HCON ON|OFF
CALC:MATH:MODE LIN|LOG|POWER
Operating Manual 1302.6163.12 - 03
Instrument Functions
Analyzer Mode