HP 8712C, User Manual, Page: 101 / 559

I
Making Measurements with the Auxiliary Input
The auxiliary input (AUX INPUT) is located on the rear panel of your
analyzer. This input is designed to monitor sweep related dc control signals of
devices generally used in conjunction with the analyzer, such as a dc-biased
or a Voltage Controlled Oscillator (VCO).
The AUX INPUT is
not
recommended for use as an oscilloscope, for several
reasons. This input is sampled only once per data point regardless of sweep
speed, bandwidth, or number of points per sweep, and sampled data points
may not occur at evenly spaced intervals unless the analyzer is in CW mode.
The AUX INPUT sampling rate depends upon the instrument state and sweep.
In CW mode with the fastest possible sweep time
set to
AUTO), system bandwidth has the most significant effect on this timing. Data
points are typically taken at about 0.2, 0.6, 7.2, and 70 ms in wide, medium,
narrow, and fine bandwidths, respectively. This effect must be taken into
account if attempting to view signals that are unrelated to the sweep ramp.
For best accuracy, input signal slew rate should be less than 700 volts per
second.
Even though the AUX INPUT is not recommended for use as an oscilloscope,
it is possible to view sine wave signals up to about 400 Hz with reasonable
accuracy by placing the analyzer in CW mode with wide system bandwidth.
Nominal impedance
10
Accuracy
o f r e a d i n g + 2 0
Calibrated range v
Usable range v
Max input
v
Level
v
3-48