TECHNICAL NOTE – OPERATION OF MT4000 TWTA
10/24/03
TN4000-3
MCL, INC.
44 of 46
Failure to avoid above conditions will void warranties!!
Any of these conditions indicate that a critical system parameter is either out of adjustment or the
fault conditions are no longer recognizable. If these conditions should exist, no further attempt
should be made to use the amplifier system until the defective circuitry or adjustment is
corrected. Of most concern to the operator is potential damage to the TWTA tube because of its
cost and the down time required for repair and/or replacement. Therefore, any parameter relating
to the TWTA tube should be analyzed immediately to prevent damage.
5.3 Power-Up
Procedure
When the above check list has been completed and the caution list is reviewed, the system is
ready for activation. To activate the system, the following steps should be followed:
1.
Activate the HPA Main Power circuit breaker. The HPA display and various front panel
LEDs will illuminate.
2.
Press the Local & Standby buttons to verify that HPA is in filament delay and will not go
into Transmit without your interaction. Check that Delay is indicated on the Main screen,
on the Delay LED, and the Standby LED is flashing. Remaining Filament delay will be
displayed on the first line of the main screen.
3.
Set the RF On/Off control to the Off position.
4.
Go to the Gain screen and set the attenuation level to 32.0 dB.
5.
Check for continuous illumination of the Standby LED at the end of the 3 minute warm-
up cycle. Also the main screen will display forward power instead of remaining filament
delay time.
CAUTION
