HP 8642A Operation And Calibration Manual

Model 8642A/B
Operation
Modulation, <PM (cont'd)
HP-IB
Codes
Comments
Example
Phase modulate the RF output with an external, 1 Vpk, dc-coupled source, 2 radians <l>M
devia tion, at a ra te determined by the external source's frequency.
ENTRY
!
MODULATION SOURCE
ENTRY DATA
LOCAL
(keys)
~
."
[mocl
[ SHIFT I
....
ITJw
0
0
...
(program
PMXD PM 2 RD-
codes)
* These codes are not independent and might need to follow a specific sequence for entry.
Refer to the discussion about Sequence Dependency, which begins on page 3-12 in the
HP-IB portion of this Section III.
Display
I 0 0.0 0 0 0 0 0 m z
-{ Lt 0.0 ] m
FREO
The RF output is being externally phase modulated with an external dc-coupled source
(as indicated by the <l>M, EXT, and DC annunciators). <l>M deviation setting is 2.00
radians per volt. Modulation frequency is not monitored by the Signal Generator when
an external modulation source is used. The cursor above the .pM setting indicates <l>M is
the active function.
Keys Codes Keys Codes
<PM
PM
INT + (EXT DC) PMBD
MOD FREQ
MF OFF
ON PMOF, PM ON
INT
PMNT
rad RD
EXT AC PMXA
kHz
KZ
EXT DC PMXD Hz HZ
INT + (EXT AC)
PMBA SPCL
SP
Modulation Types Not Possible During RF Frequency Sweep
During Stepped Frequency Sweep, FM and <l>M are allowed in manual or single sweep
mode only. During Phase Continuous Frequency Sweep (Special Function 123), all
modulation types are allowed.
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 IDS (depending OIl modula-
tion frequency), with a loss in modulation frequency accuracy, by selecting Modulation
Frequency Correction Off (Special Function 113). For more information, refer to
"Speeding Up Modulation Switching Time" on page 3-132.
3-123

HP 8642A Specifications

General

Brand	HP
Model	8642A
Category	Inverter
Language	English