Question 1

An amplifier shows low gain across the whole band on the network analyzer. Walk me through what you check.

Accepted Answer

This is the classic bench question. They want to hear an ordered process that rules out the setup before blaming the unit. Confirm the calibration and the cables first, since a bad cal or a loose connector fakes low gain Check supply voltages and bias current against the procedure before touching any part Compare against a known-good unit if one's on the shelf Work stage by stage with probes or test points to find where the gain drops Look for the usual suspects: a lifted ground, a cracked chip cap, a damaged transistor

Question 2

A unit passes on the bench but oscillates once it's bolted into the chassis. What's going on?

Accepted Answer

Oscillation in the final assembly is a real, recurring headache. It shows whether you understand feedback paths and grounding, not just test scripts. Suspect a feedback path the open bench didn't have, like cavity resonance under the lid Check that the housing ground and every mounting screw are making good contact Look at gaskets, absorber material and whether the lid changes the behavior Watch the spectrum analyzer while probing to find the frequency and chase where it couples Document what changed it so engineering can decide on a fix

Question 3

How do you calibrate a vector network analyzer, and how do you know the cal is still good during the shift?

Accepted Answer

Every number you log depends on the cal. Engineers want to know you won't hand them a week of data built on a drifted setup. Name the method you've used, such as a short, open, load and thru cal or an electronic cal module Set the frequency range, power and averaging to match the procedure before calibrating Torque connectors with the right wrench and keep test cables from getting flexed around Verify with a known standard or a golden unit at the start and middle of the shift Recalibrate after a cable swap, a temperature change or anything that looks off

Question 4

What's the difference between reading output power on a power meter versus a spectrum analyzer?

Accepted Answer

Mixing these up leads to wrong pass or fail calls. It's a quick way to test whether your RF basics are real. A power meter with the right sensor gives the most accurate total power A spectrum analyzer shows power by frequency, so you see harmonics and spurs Analyzer settings like resolution bandwidth and attenuation change what you read Use attenuators so you don't overload or damage either instrument Use the meter for the power spec and the analyzer for spurious and harmonic checks

Question 5

How do you bias up a GaN or LDMOS stage without damaging it?

Accepted Answer

Parts in power amps are expensive and easy to destroy. A wrong power-up sequence can kill a transistor in an instant. Follow the procedure's sequencing, which for depletion-mode GaN usually means gate voltage before drain Start with current limits set on the supply and watch drain current as you adjust Terminate the output into a proper load before applying RF Power down in the reverse order Say plainly if you've only done this on one device family and would check the data sheet

Question 6

Tell me about a rework job on a fine-pitch or bottom-terminated part.

Accepted Answer

A lot of your time goes into rework. They want to hear real technique, not just that you can solder. Name the part type and the tools, such as hot air, a preheater and a microscope Explain how you protected neighboring parts and the board from heat Describe cleaning the pads and applying fresh paste or flux Say how you inspected the joint afterward and retested the unit Mention the workmanship standard you worked to

Question 7

How do you keep yourself safe around high-power RF or high voltage?

Accepted Answer

Test floors carry burn and shock hazards. They're screening out people who'll hurt themselves or a coworker. Never open or probe an amp while RF is on unless the procedure says to Always terminate outputs into a rated load and never leave a port open Discharge capacitors and verify with a meter before touching anything Follow lockout and interlock rules even when you're in a hurry For audio, mention bleeding filter caps and working one-handed near tube supplies

Question 8

A unit fails in the thermal chamber but you can't make it fail on the bench. What do you do?

Accepted Answer

Intermittents are where good techs separate from average ones. They want patience and a method. Get the exact temperature, time and test step where it failed Try to reproduce with a heat gun or freeze spray on suspect areas Look for cracked solder, a marginal part or a connector that shifts with heat Keep a log of each change so you don't repeat tests Escalate with data if it's likely a design margin issue and not a build defect

Question 9

A unit misses final spec by a hair and the shift lead wants it shipped. What do you do?

Accepted Answer

This tests integrity and judgment. Defense and telecom customers audit test records. Don't pass a unit that failed, and don't change the recorded result Recheck the setup in case the fail is a measurement error Flag it for engineering, who can approve a deviation or a rework Stay calm and respectful with the lead while holding the line

Question 10

Tell me about a failure you tracked to its root cause. How did you write it up?

Accepted Answer

Your write-ups feed yield reports and design changes. A good root cause saves a product line from a long run of repeat failures. Describe the symptom and how often it was showing up Walk through the tests that ruled things out Name the cause and how you proved it, ideally by fixing and retesting Explain what you wrote in the report and who used it Mention any process change that followed

Question 11

Tell me about a time you disagreed with an engineer about test data.

Accepted Answer

Techs who stay silent let bad data through. Techs who argue badly wreck working relationships. Set up what you saw and why it didn't match the expected result Show how you brought data rather than opinion Explain how you settled it, perhaps by measuring together Share what you learned, even if the engineer turned out to be right

Question 12

You've mostly repaired audio amps. What carries over to RF production work?

Accepted Answer

Plenty of applicants come from guitar and hi-fi repair. The manager wants to know you see the gaps clearly. Schematic reading, bias setting and stage-by-stage troubleshooting carry straight over Your soldering and safety habits with high voltage transfer too Admit that impedance matching, network analyzers and microwave layout are new Name what you're doing to learn them, like a course or bench time with a mentor

Amplifier Technician interview questions and how to answer them

The 8 questions you will almost certainly get

A forgettable answer, and a better one

"An amplifier shows low gain across the whole band on the network analyzer. Walk me through what you check."

"A unit passes on the bench but oscillates once it's bolted into the chassis. What's going on?"

Questions to ask them

Need more Amplifier Technician interviews to prep for?

The question	What they want to know	Your angle
An amplifier shows low gain across the whole band on the network analyzer. Walk me through what you check.	This is the classic bench question. They want to hear an ordered process that rules out the setup before blaming the unit.	Confirm the calibration and the cables first, since a bad cal or a loose connector fakes low gain
A unit passes on the bench but oscillates once it's bolted into the chassis. What's going on?	Oscillation in the final assembly is a real, recurring headache. It shows whether you understand feedback paths and grounding, not just test scripts.	Suspect a feedback path the open bench didn't have, like cavity resonance under the lid
How do you calibrate a vector network analyzer, and how do you know the cal is still good during the shift?	Every number you log depends on the cal. Engineers want to know you won't hand them a week of data built on a drifted setup.	Name the method you've used, such as a short, open, load and thru cal or an electronic cal module
What's the difference between reading output power on a power meter versus a spectrum analyzer?	Mixing these up leads to wrong pass or fail calls. It's a quick way to test whether your RF basics are real.	A power meter with the right sensor gives the most accurate total power
How do you bias up a GaN or LDMOS stage without damaging it?	Parts in power amps are expensive and easy to destroy. A wrong power-up sequence can kill a transistor in an instant.	Follow the procedure's sequencing, which for depletion-mode GaN usually means gate voltage before drain
Tell me about a rework job on a fine-pitch or bottom-terminated part.	A lot of your time goes into rework. They want to hear real technique, not just that you can solder.	Name the part type and the tools, such as hot air, a preheater and a microscope
How do you keep yourself safe around high-power RF or high voltage?	Test floors carry burn and shock hazards. They're screening out people who'll hurt themselves or a coworker.	Never open or probe an amp while RF is on unless the procedure says to
A unit fails in the thermal chamber but you can't make it fail on the bench. What do you do?	Intermittents are where good techs separate from average ones. They want patience and a method.	Get the exact temperature, time and test step where it failed