HP 8642A Operation And Calibration Manual

Model 8642A/B
Operation
Modulation, Pulse (cont'd)
Example
HP-IB
Codes
Commen1s
Pulse
modulate the RF output with an external dc-coupled source, at a rate and duty
cycle determined by the external source (starting with pulse modulation off)
ENTRY
MODULATION SOURCE
LOCAL
(keys)
( SH1Fl I
PiJLSE
GJ
~
(program
codes)
Display
Inn n n n n n n m 7
I ILl ILI.ILI ILl ILl ILl ILl ILl ,. I L
FAEQ
[moe]
PLXD PLaN
T
r
l/I lE
'-' '- ~ -
ENTRY
EJ
PU .. SE ~
GJ ON
EXT
_Iunn TIm
I 1 ILI.ILI JJ •
DC .AMPTO
The RF output is being externally pulse modulated with an external, dc-coupled
source (as indicated by the word PULSE and the annunciators EXT and DC). the
cursor above the pulse modulation display indicates that pulse modulation can be
toggled off and on by selecting the LOFF oN ) key.
Keys Codes
PULSE
PL
MOD FREQ
MF
INT PLNT
EXT
DC
PLXD
OFF,
ON
PLOF, PLON
kHz
KZ
Hz
HZ
SPCL
SP
Modulation Restrictions with other Functions
Pulse modulation and AM are not possible during amplitude sweep. Also, AM and
pulse modulation are not possible when ALC Off (Special Function 4) is selected.
Spurious Signals (Spurs) That Occur with the Internal Source
Internally generated spurs (with specified levels less than -100 dBc) might be present
when the internal modulation oscillator is in use. These spurs will be eliminated when
no internal modulation source is modulating the carrier, and the modulation oscillator
output (MOD OUT) is off.
Modulation Switching Time
The time required to turn on the internal modulation oscillator or to switch between
modulation frequencies can be reduced by approximately 200 ms (the time depends on
modulation frequency), with a loss in modulation frequency accuracy, by selecting
Modulation Frequency Correction Off (Special Function 113). FOI more intormation,
refer to "Speeding Up Modulation Switching Time" on page 3 -13 2.
3-129

HP 8642A Specifications

General

Brand	HP
Model	8642A
Category	Inverter
Language	English