TECHNICAL NOTE – OPERATION OF MT4000 TWTA
10/24/03
TN4000-3
MCL, INC.
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2. Exciter Adjustment
Set the exciter at this level and lock all exciter output adjustments permanently. Use
devices that must be removed to readjust output. Alternately, set exciter at maximum
and insert attenuation in the line to limit power available at the TWTA.
3. MT4000 Trip Levels
The Tube Overdrive Fault and the Tube Overdrive Alarm levels were set by MCL to
protect the TWT. If the Tube Overdrive Alarm occurs this is an indication to the
operator that the tube drive level is approaching the Tube Overdrive Fault. Once the
tube drive level has exceeded the Tube Overdrive Fault level the HPAs RF switch and
high voltage power supply will both be turned off until the RF drive level is backed
down.
To change the Tube Overdrive Fault level from the factory set level may
result in degradation or permanent damage to the TWT.
5.0 INITIAL TURN ON OF THE HPA
The following procedure should be perform the first time the HPA is turned on after receipt from
MCL or after it has been in storage.
5.1
Initial Turn-On Check List
All MT4000 TWT amplifiers are ready to be activated when the following check list has been
complied with:
1.
The Installation procedure found in TN4000-2 Technical Note, Installation Guide for
MT4000 as been completed.
2.
The HPA Main Power circuit breaker should be in the off position.
3.
The MT4000 is properly mounted in the cabinet and the cabinet is firmly bolted in place.
Make sure the top cover of the MT4000 is attached; the cover is part of the
cooling circuit.
CAUTION
CAUTION
