A DC keep-alive potential:

Question 1 of 27070XI0YQOSWK79Xcff1nTAi

A DC keep-alive potential:

Question 1 of 27070

Q

A DC keep-alive potential:

🔍 Key Concepts

• TR tube (transmit-receive tube) function in a radar duplexer • What happens to a gas-discharge tube when a small DC voltage is applied continuously • Difference between partial ionization and full ionization of gas in a tube

💭 Think About

• Think about what condition the TR tube should be in just BEFORE a strong transmitter pulse arrives so it can respond quickly but still be controllable. • Ask yourself: does a keep-alive potential drive the tube all the way into full conduction, or just close enough that it can fire easily when the real pulse comes? • Consider how a keep-alive voltage affects the sensitivity of the tube to the transmitter pulse—does it change the gas state, the bias condition, or both?

✅ Before You Answer

• Verify what the phrase "keep-alive" implies in electronics (ready state vs fully operating state). • Check which option correctly links increased sensitivity with the idea of partial vs full ionization of the gas in the TR tube. • Eliminate any choice that would make the TR tube conduct all the time instead of only when the transmitter pulse is present—would that still allow normal radar operation?