Aeroflex 2030 Series, Руководство по эксплуатации

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OPERATION
3-1-58
RF level utility
Selecting [RF Level Utility] from the Utilities Selection Menu 2 displays the RF Level
Utility Menu shown in Fig. 3-1-50.
Fig. 3-1-50 RF level utility menu ([CW Burst Control] and associated text only appears when
the relevant option is fitted)
Extended hysteresis
Pressing the [Extended] soft key toggles the status (Enable/Disable) of extended
hysteresis. When enabled, this provides an electronic level function which uses the internal D/A
converter, rather than the attenuators, to provide an uninterrupted (glitch-free) level control. This
increases the electronic level control range to +12 to -18 dB. A
+HYST or -HYST message is
displayed on the Sig Gen menu to indicate when in hysteris and in which direction.
During normal operation the RF output is controlled as shown in Fig. 3-1-51 by
electronically controlling the output level over a limited range (normally approximately 0 to +6
dBm) and switching in 6 dB attenuator pads to provide lower RF levels.
When the hysteresis function is enabled and a keyboard entry of the RF level is made, the
signal generator sets the level in the normal way. However, when the rotary control is enabled
and used to adjust the RF level, the normal attenuator changes are suppressed. When the level is
increased, the attenuator change is suppressed for 6 dB above the normal range and
+HYST is
displayed. Similarly, when the level is reduced attenuator changes are suppressed for 12 dB
below the normal range and
-HYST is displayed. When the extended hysteresis range is
exceeded the attenuator and the electronic control are reset to values corresponding to the normal
operation of the generator. An example of extended hysteresis operation is shown in Fig. 3-1-52.
With the rotary control in use in the hysteresis range of operation, the generator can be
instructed to set the RF level to the same value, but set using the [V], [mV], [
μ
V] or [dB] keys.
This is a useful facility if the user is investigating squelch systems and wants to ensure that
varying the level around the current value will not result in an attenuator change.
Offsets
LOCAL
Extended
CW Burst
Control
RF Level
Limit
RF Level Utility Menu
Extended Hysteresis : ENABLED
CW Burst Suppression
for Pulse Modulation : ENABLED
C1892