Paradise Datacom 4 RU Chassis, Руководство по эксплуатации

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4 RU SSPA Chassis Operations Manual 201627 REV X 37
2.2.4.4 Fault Latch
Determines the alarm reporting condition. A latched alarm will remain indicated on the
front panel until the operator clears the alarm by pressing the “Enter” button. Unlatched
alarms will allow the summary alarm indicator to stop displaying the alarm condition if
the circumstance creating the alarm has been cleared or corrected.
2.2.4.5 Low RF / Automatic Level Control
Alerts the user when the output power falls below the threshold value, which is
adjustable by the user with 1dBm steps by selecting the “Set Level” menu item. Fault
handling is adjustable by user, who may choose between Alert Only (Minor Fault),
Fault (Major Fault), and Ignore (No Fault tracking).
In addition, the user may select Automatic Level Control from this menu.
1. Select [3] ALC On;
2. Select [5] Level;
3. Use the arrow keys to set the desired output level.
Once activated, the ALC will take control of the amplifier’s attenuation setting to
maintain the desired RF output power level and will not allow any attenuation
adjustments via the front panel. The ALC circuit will have the greatest ability to adjust
for positive and negative RF input level changes when the amplifier’s gain level is
typically 65 dB.
By following the steps below, the optimum ALC RF input level can be set quickly.
1. Using the front panel menu, make sure the amplifier is not in ALC mode;
2. Set the amplifier attenuation level to 10 dB;
3. Apply a CW RF signal to the amplifier;
4. Use a power meter to measure the output power of the amplifier;
5. Adjust the RF input level until the desired output power level is achieved;
6. Follow the steps listed above to activate the ALC control. The ALC will take
over the control of the output level and maintain the RF output level set
point.
The ALC has the ability to accurately control the RF output power over a 15 dB range
from P
sat
. The ALC will operate over a 20 dB range, but the accuracy of the last 5 dB
will suffer. For example, if the saturated power from the amplifier is 59 dBm, the lowest
accurate power setting during ALC control is 44 dBm.
If the output power set point is set outside the operational range of the ALC circuit, the
ALC will adjust the output power to the lowest possible level and set a minor fault on
the amplifier’s front panel.
Note: Automatic Level Control is inactive when the system is in N+1 operation.