TWTA Spurious Switch definition
TWTA Spurious Switch. Off ("TSSO"). For the purposes of --------------------------------- defining a successful operating channel, with no interruptions to traffic on that channel, a TSSO is defined as any unwanted shut-off of a TWTA due to the automatic protection circuitry in its EPC. This EPC design contains an automatic reset unit ("ARU") that provides EPC operation within 300mS of a microdischarge event. If no other microdischarge event occurs within the next three minutes, the ARU will reset itself automatically. Two microdischarge events occurring within a three minute ARU interval on the same EPC may trigger a spurious switch off shutting down the EPC. If the ARU shuts down the EPC, causing the loss of the transponder TWTA function, the EPC and hence the TWTA must be restarted by ground command. The EPC timer will automatically apply the high voltage after five minutes and the TWTA will be back in service. In high power mode, TWTA shut-down includes shut-down of either one or both of the parallel combined traveling wave tubes ("TWT"). In medium power mode, TWTA shut-down is the shut- down of the one shut-down of the one operating TWT. A microdischarge event is any very short unwanted interruption of the Transponder RF signal. The micro-discharge event period is typically 1-50 mS duration.