HP 8901B Operation And Calibration Manual page 68

1-4
- -
Input signal not
sensed
-
- - - -
HP 89016 setting
up measurement
The Front Panel
1 .
2.
3.
Take a look at the
H I '
8901Bs Front Panel. Notice that label
brackets have been placed over each key group to help you quickly find the
function desired.
Note the gold and blue keys. These keys will enable you to select the
"shifted" functions.
As
this guide will demonstrate, the shifted functions are
selected by pressing the gold or blue key and then the desired function key.
Switch the HP 8901B
f r o m
STBY
to
ON. Notice that as the HP 8901B
powers up, it performs a self-test that includes turning on all front
panel lights.
The Display
The HP 8901B keeps you informed of its operating status by the dashes and
error codes it places in its display.
Interpreting the Dashes
4.
Adjust your signal generator to
-40
dBm. This causes the HP 8901B
to place two dashes in its display. Two dashes indicate that the level of
the input signal is too low for the instrument to detect in its current
measurement mode.
5. Set the signal generator to 0.0 dBm. Once the HP 8901B detects an
input signal, it removes the two dashes from its display. Sometimes you
will see the HP 8901B replace the two dashes with four dashes. Four
dashes indicate that the instrument is involved in internally setting up the
measurement. If the HP 8901B displays four dashes for more than a few
seconds, the instrument may be having difficulty
tuning
to an unstable
input signal. (The HP 8901Bs Track Mode tuning, described later in
this chapter, is typically a good choice for tuning to unstable signals.)
Interpreting Error Codes
6.
Press the
CALIBRATE
key. (See the adjacent instrument diagram for the
key location.) The HP 89018
will
display Error 21 to inform you that you
have attempted to select an operating condition that is not compatible
with the measurement you are making. Error codes like this will keep
you informed of both operator errors and input signal problems. The
reference chapters (2, 3, and 4) list the error codes that can be encountered
for each measurement along with recommended recovery actions.