AR 10037990, Руководство по эксплуатации и обслуживанию, Страница: 44 / 54

Model 250T6G18
24 Rev A
Remote operation is determined by the application (software) program in the system controller. This application
program will aid the user in generating the Command Codes and displaying/monitoring the Status Codes. Consult
the application program users instructions for Remote operation procedure.
The application program should issue only one string at a time. After each functional command is issued the
status should be checked to ensure that the command has been properly executed. The application program should
allow sufficient time for the function to be completed before checking the status.
The application program should facilitate checking the status just prior to issuing a command - since the status
could have been changed by a fault condition of the amplifier or by operator activation of the amplifier. Periodic
checking of the status is also recommended.
3.9 PULSED OPERATION
This amplifier is provided with a rear-panel BNC connector which can be used for pulsing the beam of the TWT
and hence the RF output. As compared with providing a pulsed RF input, pulsing the beam of the TWT offer low
noise between pulses. It also offers reduced prime power consumption for low duty factor pulsing, since the beam
current is off most of the time.
In the CW mode (not pulse mode) the amplifier pulse input is pulled high to permit CW operation with no
external jumpers. To set the amplifier for pulse or CW operation, enter the setup menu and push MORE until
reaching the last setup screen, which says “amplifier is set to...” Push SET to achieve the mode of operation
desired.
In the pulse mode, the impedance of the pulse gate input is approximately 50 ohms. The logic is positive; a logic
high (greater than +2V) turns the pulse on.
Two modes are selectable from the front panel menu:
•
CW
•
Pulse
In CW mode it is expected that the user will NOT connect a pulse generator to the pulse input.
CAUTION:
Do not connect a pulse generator to the pulse gate input
when operating in the CW mode.
When switching from PULSE mode to CW mode, a warning is displayed to alert the user to disconnect the pulse
generator. When disconnected, press SET again to set to CW mode.
If no generator is connected and the CW mode is selected, the unit will operate in the CW mode and the amplifier
will amplify the RF input signal, ie the unit will operate as a unit without pulsing.
In the pulse mode it is expected that the user will connect a pulse generator to the pulse input. If a generator is
connected and the PULSE mode is selected, the unit will operate in the pulse mode; it will amplify the rf only
when the pulse input is set to high level, into the pulse input’s approximately 50 ohms input impedance. This
impedance to signal ground has been selected to reduce reflections. For best response, the user should make the
connection to the generator using a 50 ohm coaxial cable.
NOTE: If the user does not have a pulse generator connected to the pulse input, there will be no rf output (when
the pulse mode is selected).