HP 8642A Operation And Calibration Manual

Model 8642A/B
Operation
Knob (cont'd)
Comments
You Can Use the Knob to Determine Function Limits
The Knob can be used to determine the approximate limits for all function settings.
However,
the limits reached with the Knob will not cause the Signal Generator to
dIsplay a message describing the reason for the IJmitation. Use a Data entry beyond the
limitation to cause the Signal Generator to describe a limitation.
Undisplayed Digits May Appear to Affect Maximum Settings
You can step in increment set values that will not be displayed when the resolution of
the current setting is coarser than the increment set value. For example, with FM
deviation set to 1.30 MHz, an increment change of 1 kHz will not be displayed until 10
increments have been stepped. Consequently, if at any time you step the displayed
setting by that undisplayed increment setting, and then turn the Knob, the Signal
Generator may seem to not be able to reach its maximum value. For example, stepping
from I. 300 MHz (displayed value of 1.30 MHz) to 1.30 I MHz (displayed value 1. 30
MHz), and turning the Knob will only allow a maximum displayed value of 1.49 MHz
(since
the maximum possible deviation is 1.500, not 1.501 MHz).
Partial Preset Does Not Change Increment Set Values
Select PARTIAL ( I SHIFT) I INSTR PRESET) ) to put the instrument in a known
sta te without resetting increment set values.
How Fast You Turn the Knob Affects the Knob Sensitivity
Knob sensitivity changes from fine to coarse when Knob rotation is changed from slow
to fast (unless Knob Increment is in use).
HP-IB. Knob Resolution Could Be Useful Via HP-IB
Knob Increment, Knob Hold, and moving the cursor with the cursor posItioning keys
can be programmed via HP-IB The programmability of these functions could be
useful, for example, when preparing a setup before setting the instrument to local.
Physical
Knob rotation must be performed from the front panel.
The Meaning of Multiple Cursors
The Knob Hold function and the Knob Increment function can both be useful, but
initially might cause some confusion by displaying so many cursors. Knob Hold could
ca use you
to have as many as three cursors in the display at once.
The following summary is listed by quantity of cursors in the display.
One cursor in the display:
1. One cursor over a digit:
5 5 5.0 0 0 0 0 0 m z
FREO ~MPTD
Indicates normal active function status. Also indicates the least-significant digit
that will change as you turn the Knob.
3-145

HP 8642A Specifications

General

Brand	HP
Model	8642A
Category	Inverter
Language	English