Operation
Model 8642A/B
Modulation, AM (cont'd)
NOTE
With simultaneous internal and external modulation, the external
signals should not cause the AM depth to exceed 99.9%. If this
limit is exceeded, the Signal Generator could go out of lock which
causes queued up Hardware Error messages. Also, the external
AM/PULSE INPUT does not respond linearly to inputs greater
than approximately 1.2 Vpk.
Example
Amplitude modulate the RF output with an external, 1 Vpk, dc-coupled source, 80%
AM depth, at a rate determined by the external source's frequency.
LOCAL
(keys)
«
"2
-A-
ENTRY
[AM]
MODULATION SOURCE
[EXT
DCJ
ENTRY
r^i
DATA
18
1
UU ULJ
AMXD AM 80 PC
Display
/0 0.0 00000/nz
FREQ
BE.BPL
LO AM EXT
-IW 0.0 3/1?
DC AMPTD
The RF output is being externally amplitude modulated with an external dc-coupled
source (as indicated by the AM, EXT, and DC annunciators). AM depth setting is
80.0%
per volt. Modulation frequency is not monitored by the Signal Generator when
an external modulation source is used. The cursor above the AM setting indicates AM
is the active function. The LO annunciator may be indicating that the external
modulation source is at a dc level (all inputs appear as "LO") or that there is a sinewave
input less than 1 volt.
HP-IB
Codes
Keys
AM
MOD FREQ
INT
EXT AC
EXT DC
INT+ (EXT AC)
Codes
AM
MF
AMNT
AMXA
AMXD
AMBA
Keys
INT+ (EXT DC)
OFF ON
%
kHz
Hz
SPCL
Codes
AMBD
AMOF,
AMON
PC
KZ
HZ
SP
3-100
To Next Page
