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RF & Wireless — question 4 of 10

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During a radiated emissions pre-scan, you see a narrowband spike well above the limit line at exactly 120 MHz -- which is the third harmonic of your microcontroller's 40 MHz crystal -- along with smaller spikes at other harmonics of that same clock. Walk me through how you'd confirm the source and the first three things you'd try to fix it.

How sure are you?

Being confidently wrong costs more mastery than admitting a guess — that is deliberate, and it is how misconceptions get found.

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