please contact Technical Support, depending on the Region: Support | Tektronix
I would recommend contacting your Local Tektronix Sales Representative and the Regional Technical Support for this topic.
Here I can only point to the Datasheet, frequency Burst is indicated for channel A and B: Microwave/Counter/Analyzer with Integrated Power Meter | Tektronix
Frequency Burst is not available on Input C of MCA Models. This feature was removed.
It is available on FCA3020 and FCA3120 – 20 GHz Only