Hp-Ib Codes; Comments - HP 8642A Operation And Calibration Manual

Operation Model 8642A/B
Modulation Oscillator (cont'd)
HP-IB
Codes
Comments
3-13 :.
Example
Set the Signal Generator to output a 2 Ypk, 10kHz signal at the MOD OUTPUT
connector.
ENTRY
LOCAL
(keys)
mID
fREO
..
(program
codes)
Display
mO
T/r/IIT
I
U
..u.u
U
I
DATA
OJ
(J]
rn
mV
8
MF 10 KZ ML 2 VL
The modulation output level has been set to LOOY.
ENTRY DATA
MOO OUT
l][)
fPEO
OJ
[YJ
I
U
I7i I7i T/
m'
-, 1
u.u..u
I,
A"'PTO
Any function which
is
using the modulation oscillator as a source, (MOD OUTPUT or
internal AM, FM, <PM, or pulse modulation), now has a rate of 1000 kIlz regardless of
any previous modulation oscillator rate setting. The cursor above the modulation output
value indicates Modulation Output is the active function.
Keys Codes
MOD FREQ
MF
MOD OUT level ML
kHz KZ
Hz
HZ
V VL
mV
MV
SPCL
SP
Speeding Up Modulation Switching Time
A
t
instrument turn on, all mod ula tion oscilla tor frequency bands are characterized and
given a calibration factor (Modulation Frequency Calibration). When the modulation
oscillator frequency is set or the modulation oscillator placed in use, the selected
modulation oscillator frequency and its individual frequency band are recalibrated to
correct for inaccuracies due to changes in temperature (Modulation Frequency
Correction). A single calibration of all modulation oscillator frequency bands can be
Initiated using Special Function 248.
If faster switching between modulation frequencies is desired, Modulation
Frequency Correctil,n can be disabled by selecting I'vlodulation Frequency Correction Off
(Special Function 113). This special function decreases switching time by approximately
200
TIlS.
Automatic modulation frequency correction can be fe-enabled by selecting