This is how the old good Tektronix TDS380 acquires a 500MHz signal from Marconi Instruments 2031 signal generator. Very stable, calm trigger and display. No jumping around, albeit using 16x averaging.
And this is a picture of how 800MHz signal looks on the same scope.
And, last image is, the same setup, but a 1GHz signal, same scope.
Last updated on 2022:12:20 at 01:26 UTC