Rise time is abt 700 ps which would yield a bandwidth of 0.4/700x10^-12 = 570 MHz (which sounds a bit optimistic), but certainly way better than the original 70 MHz…
“a bit optimistic” is of course an understatement. But I am a bit at a loss as to how to interpret the rise time I measure with the pulse generator. It _looks_ like it meausere the whole pulse, so…
As a check I also tested my 5 year old OWON PDS7102T – a 100 MHz scope. Risetime measured was a bit above 3 ns (A bit difficult to measure, but not far off), resulting in 133 MHz. Sounds reasonable. (see attachment). So this measurement seems to yield a more trustworthy result.
But: The OWON only rises to 12 Volts, whereas the upgrades 2072A rises to almost 40 Volts (both measurements with the pulse generator directly to the BNC, 1 meg input).
As a check I used the TG output of my 815-TG at various frequencies (0dBm output) and measured the Vrms reported by the scope. See 2nd attachment.
Note: the output of the 815 TG is not very well defined as we know, which explains the bumps and irregularities, but this measurement shows a bandwidth of just below 400 MHz. Sounds legit.
(nb: boy Am I glad I decided to buy the 2072 and not a new OWON....
)