Comtech EF Data XTRT-400C-BUC Operation And Installation Manual page 113

Initial Turn-On Procedure
This procedure applies the first time the unit is operated at your site and after any major
repairs of the amplifier.
CAUTION - Operators and Service Personnel must observe the instructions in the following paragraphs.
Failure to comply may cause permanent damage to the amplifier and void the warranty.
Pre-power Check
1. Prime power is within the specified limits of the amplifier.
2. The RF output is terminated with a load capable of dissipating rated RF output
power and the load has a maximum VSWR of 1.3:1.
3. The RF drive signal is within the frequency range of the amplifier and +5dBm or
less with the amplifier set for minimum gain (attenuation at max approx. 30 dB).
CAUTION - Operate the amplifier within the power limit specification. Exceeding the input power will
cause a Helix Current Fault. Failure to comply may permanently damage the TWT.
Turn-on Sequence
Set the AC Power switch to ON.
1. Within two minutes after setting AC power ON, Touch the HV button and make sure
the high voltage has been selected OFF.
2. In the "Amplifier Tab" described earlier in this chapter select the attenuator tab and
using the adjust knob adjust the attenuation to maximum.
3. Connect an RF monitor to the output load assembly.
4. Connect an RF test generator or the operational RF drive source to the RF Input on
the Rear Panel.
5. With the attenuation set to the maximum level, set the RF drive source for a
maximum output of +5 dBm.
6. Wait until Filament Time Delay cycle is complete (approximately three minutes). The
Standby mode should be enabled, turn the RF drive OFF.
7. Touch the HV key on the "Main Menu Tab" and turn on the HV as described in the
previous section of this chapter.
8. Turn on the RF drive signal. Slowly increase the RF drive to the TWT by touching the
Green HV on indicator on the "Main Menu Tab" and rotating the adjust knob clock
wise. Monitor the RF output power.
9. Touch the HV button on the "Main Menu Tab" and follow the high voltage turn-off
sequence.
The TWTA is ready for operational service.
MNC-0400-071
EAR EXPORT CONTROLLED: The information contained in this Manual refers or relates to a product that is subject
to the U.S. Export Administration Regulations (EAR). Transfer of data herein by any means to a Foreign Person,
whether in the U.S. or abroad, may require an export license from the U.S. Department of Commerce.
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Operation
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