TECHNICAL NOTE – OPERATION OF MT4000 TWTA
10/24/03
TN4000-3
MCL, INC.
9 of 46
3.1
Discrete Controls & Indicators
The indicators & controls described in this section are provided on the HPA front panel. Further
description of these functions follows in later sections of this document.
3.1.1 Filament Off Button/LED
When this button is activated, from any state except Transmit, the Filament Power Supply will be
turned off. When illuminated this Yellow LED will indicate that the HPA is in the Filament Off
state.
3.1.2 Delay
LED
Yellow LED which when illuminated will indicate the HPA is going through a filament warm up
cycle and is not yet in Standby.
3.1.3 Standby
Button/LED
There are two functions for this button. First, if pressed while the HPA is in the Filament Off
state filament delay will be initiated, the Yellow LED in the button will be flashing. Second, if
pressed while the HPA is in the Transmit state the HPA will switch to the Standby state, the
Yellow LED in the button will be continuously illuminated.
3.1.4 Transmit
Button/LED
While no faults are present, if this button is activated the HPA will cycle into the HV on state.
When the Green LED inside the button is continuously illuminated, the HPA is in transmit. If
flashing, transmit has been selected, but the amplifier is still in filament delay, and upon
completion of filament delay the HPA will go into Transmit.
3.1.5 Summary Alarm LED
Yellow LED when illuminated the HPA has an alarm state that can lead to a fault condition if it
is not corrected.
3.1.6 Reset Button & Summary Fault LED
When this button is activated the a fault reset will be initiated. When the Red LED inside the
button is illuminated, the HPA has a fault and the high voltage is turned off.
3.1.7 RF On Button/LED
When this button is activated the SSA RF switch will be put into the ON state if no other
interface is causing a RF Off state. When the Green LED inside the button is illuminated, the
SSA RF switch is enabled.
