Operation
Model 8642A/B
Amplitude (cont'd)
AMPTD OFF ON
RF OFF/ON
How to Turn Off the Amplitude Output
The RF output can be turned off using the following method:
By selecting the key when amplitude is the active function (HP-IB:
APOF). The amplitude display will read AP.OFF.
When amplitude is turned off in this way, the RF output and all harmonics,
subharmonics, and all other spurs will be reduced to a level below -1 40.0 dBm (0.023 uV,
0.046 EMF uV, -33.0 dBuV, or -27.0 dB EMF uV).
• By selecting fRF OFF/ON I. Amplitude will be toggled off or on each time this key
is selected.
Amplitude does not have to be the active function to reduce RF output amplitude with
the [ RF OFF/ON~l key. This function reduces the level of the carrier frequency and
associated harmonics without adjusting the output attenuators. (Refer to Table 3-14
below.) The amplitude portion of the display reads RF.OFF.
Table 3-14. RF.OFF Output Amplitude Levels
RF
Frequency
(MHz)
1057.500001 to 2115.000000
528.750001 to 1057.500000
0.100000 to 528.750000
(except Heterodyne Band)
0.100000 to 132.187500
(Heterodyne Band Only)
"dB relative to the carrier signal's orig
Output
Signal
Attenuation
(dB)*
<-140
<-75
<-140
<-75
nal amplitude.
Harmonic
Attenuation
(dB)*
<-140
<—110
<-70
<-110
HP-IB
Codes
Comments
Keys
AMPTD
dBm
V
mV
MV
Codes
AP
DM or DB
VL
MV
UV
Keys
dB^V
EMF
OFF ON
RF OFF/ON
SPCL
Codes
DU
EMON,
EMOF
APOF,
APON
R0,
R1
SP
Overranging Specified Amplitude
Amplitudes as high as 20 dBm (2.24V, 127.0 dBuV, 4.49 EMF V, or 133.0 dB EMF uV)
can be set at any RF frequency setting, but the level is not specified above the values
listed in Table 3-1 3 (on page 3-69).
3-72
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