Teledyne HPAC-2005, Руководство по эксплуатации

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50 205356 REV T 3 RU SSPA Chassis Operations Manual
2.2.4.5.3 High RF
When this menu item is selected, an alarm is triggered when the RF output power rises
above a threshold value, which is adjustable by the operator (see
Section 2.2.4.5.5
).
This function is available in units with firmware version 6.14 and above.
The operator may set the fault handling to trigger either a Major Fault (Fault), Major
Fault with Mute, or Minor Fault (Alarm).
•
1.Fault (High RF)
— When selected, a Major Fault condition (Summary
Alarm) is triggered when RF output power rises above the set threshold
value;
•
2.Fault + Mute
— When selected, a Major Fault condition (Summary
Alarm) is triggered when RF output power rises above the set threshold
value, and the amplifier is placed in a mute state. To avoid output oscilla-
tions between the Mute and Unmute states, this fault condition will latch
itself and will not self-clear without operator intervention;
•
3.Alarm
— When selected, a Minor Fault condition is triggered when RF
output power rises above the set threshold value;
•
4.Back
— This selection displays the menu listed in
Section 2.2.4.5
,
There are several methods to clear detected High RF Fault Mute:
1. Select “Fault Clear” menu from front panel menu (see
Section 2.2.1.1.1
);
2. Apply “Fault Clear” signal from Parallel I/O port (see
Table 2-3
, pin 37);
3. Disable Forward RF fault (see
Section 2.2.4.5.1
).
2.2.4.5.4 ALC On (Automatic Level Control)
The Automatic Level Control function will take control of the amplifier’s attenuation set-
tings 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 typi-
cally 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;
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.