Nautel VX150, Operation & Maintenance Manual

Page: 151 / 179

VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL OPERATING THE TRANSMITTER
PAGE 2.2.134 VERSION 1.0 2022-12-08
Thresholds Menu
The VX transmitter has two user configurable protection thresholds: SWR Shutdown and SWR Foldback.
Adjusting these thresholds increases the transmitter’s protection sensitivity to high reflected power. See
Figure 2.2.117 .
NOTE
:
Changing these thresholds will alter the transmitter’s protection system. Decreasing these
thresholds will cause premature transmitter foldback or shutdown conditions, resulting from the lower
SWR setting.
The SWR Shutdown threshold has a factory default setting of 3.0, with an adjustable range of 1.1 to
3.0. If the measured SWR exceeds the programmed threshold, the transmitter will shut down and
require all SWR related alarms to be cleared prior to enabling RF.
The SWR Foldback threshold has a factory default setting of 1.5, with an adjustable range of 1.1 to 1.5.
If the measured SWR exceeds the programmed threshold, but is less then the SWR Shutdown threshold,
the transmitter will reduce the RF power. Once all SWR related alarms are cleared, the transmitter will
automatically return to the preset power level.
Use the Front Panel rotary knob to edit the desired threshold’s SWR setting. Press the Front Panel rotary
knob to save the change. Press Cancel button to discard any changes and return to the previous menu.
Figure 2.2.117: Thresholds Menu