ANALOG MODULATION MODE
3-82
RF level limit
With the instrument unlocked to level 1, see 'Locking and unlocking' above, pressing the
[RF
Level Limit]
key causes the
RF Level Limit Menu
shown in Fig. 3-80 to be displayed.
LOCAL
Save
Setting
RF level
Limit
Enable/
Disable
Exit
RF Level Limit Menu
RF Level Limit :
dBm
+13.0
RF Level Limit : DISABLED
C1893
Fig. 3-80 RF level limit menu
The maximum peak RF level output can be specified in the range -138 to +19 dBm. As a result
the keyed-in RF output value can be limited as a measure of protecting sensitive devices connected
to the RF output of the signal generator. Alternatively, the RF output power can be extended by
an additional 6 dB for overrange testing. If the requested output level is in the overrange region
the
uncal
message is displayed on the
Sig Gen
menu.
The RF level limit is set by selecting
[RF Level Limit]
and entering the value required. Units may
be
μ
V, mV or dB. The choice of volts EMF, volts PD and the dB reference is made by using the
RF Level Units utility (see 'RF level units' above). The RF level limit can be turned on or off by
means of the
[Enable/Disable]
key.
By pressing the
[Save Setting]
key, the RF level limit value and status is stored to non-volatile
memory which is recalled at switch-on and during an instrument reset.
When in the overrange region, the signal generator is capable of generating much higher
signal levels. If the frequency is set below 21.09375 MHz and the RF output is not
terminated in 50
Ω
, the RPP may be tripped by the internal RF signal. If this happens the
RPP can only be reset if a 50
Ω
termination is connected to the RF OUTPUT socket.