Series XT-50, XT-80, and XT-100 Amplifiers Operation 3-5
Failure to observe any of the following instructions may cause
permanent damage to the amplifier and will void the warranty.
Pre-Power Check
1. The prime power voltage needs to be within the specified limits of the
amplifier (Table 1-6).
2. If the amplifier is installed within an enclosure, the exhaust air from the
amplifier should be ducted to the outside of the cabinet so that the warm air
is not recirculated into the amplifier's air intake.
3. The RF output is terminated with a load capable of dissipating
200 Watts CW. This load has a maximum VSWR of 2.2:1.
4. The RF drive signal is within the frequency range of the amplifier's
specification and does not exceed by more than 2 dBm the input power
required to the TWT saturation point.
EXCEEDING THE INPUT POWER LIMIT WILL CAUSE A HELIX CURRENT
FAULT AND MAY PERMANENTLY DAMAGE THE TWT.
Turn-On Sequence
The pin numbers referenced in this section apply to connector J1, the interface
connector.
1. Connect Pin a to ground. This applies prime power to the TWT power
supply. Wait until the heater time delay cycle is complete (Pin G goes low).
2. Connect Pin F to ground. This turns High Voltage ON. The High Voltage
ON status line (Pin K) goes low.
3. Turn on the test RF signal source. Slowly increase the drive power to the
amplifier. Monitor the RF output power though the amplifier's built-in
power sampler or though an external coupler.
Driving the TWT by more than 2 dBm beyond the input power required to reach
the saturation point may cause permanent TWT damage.
Turn-Off
There are three shut down modes:
1. High Voltage OFF, heater at full power. If the TWTA is to be deactivated for
a short time (a few minutes to an hour), turn High Voltage OFF by
disconnecting Pin F from Pin W.
To Next Page
Loading...