Ref Set; How To Set A Reference To A Specific Frequency; How To Reference To The Signal Generator's Last-Selected Reference; How To Display The Current Frequency Reference - HP 8642A Operation And Calibration Manual

Operation Model 8642A/B
Relative RF Frequency (cont'd)
3-46
REF SET
Display
"..
0.000000m
z
FAEO REL
I
l-l
I7f I7f TI
m
- , 1
tJ.tJ .LI
Ijf
The FREQ REL annunciators indicate that the rrequency display is relative. All
subsequent frequency settings will be entered and displayed as MHz relative to the
frequency reference of 500 MHz. The absolute output frequency
IS
the displayed
frequency plus the frequency reference.
How to Set a Reference to a Specific Frequency
Setting a specific RF frequency as the frequency reference causes subsequent frequency
settings to display the current output frequency as MHz relative to the frequency
reference.
( FREQ I
REF SET ( (
SHIFT I (AMpTD I )
and the value of the desired reference
frequency (in GHz, MHz, kHz, or Hz).
Example
With a current RF frequency output of 100 MHz, configure the front-panel to allow
entry and display of all frequency setting values as an offset from a 1 MHz frequency
reference.
First select
I INSTR PRESET J.
Then perform the following steps:
ENTRY
ENTRY
LOCAL
r---'
(keys)
8
( SHIFT)
REF SET
8
..
(program
FRRS 1 MZ
codes)
Disl)lay
FflEa AEL
DATA
OJ~
_/Uf7If7I Tim
, 1
tJ.tJ .LI
II,
AMPTD
The FREQ REL annunciators indicate the frequency display is relative to a reference
frequency. The displayed frequency is 99 MHz (relative); the absolute output frequency
is the displayed frequency plus the frequency reference (99 MHz
+ 1
MHz
=
100 MHz).
How to Reference to the Signal Generator's Last-Selected Reference
Turn on the relative frequency mode from the a hsolute frequency mode by setting the
frequency reference to the last -selected va 1 ue:
CfRE'{;:D
REF SET (I
SHIFT)
LFB£QJ )
("' O ""' F ""' - F"' O "' N TO)
How to Display the Current Frequency Reference
( FREQ )
REF SET ( (
SHIFT) ( FREQ ) )