By the way, if you have any signal generator that can sweep (FY3200 will do, maybe even Tinysa), you can do it this way too:
Set the sg sweep to the measuring range you need.
In the example, I wanted to measure the 6.5MHz BSF, so I swept from 4MHz to 8Mhz in 4 seconds.
Then you can set the trigger on the Hantek to "pulse" (in the example < 260ns) to get an (approximate) starting point (if the sg does not output a synchronization trigger).
Then set Sec/Div so that the 4 seconds are captured (500ms in the example)
Now you can measure with the cursors. In the example you can see that the low point is reached after approx. 2.5 seconds. This corresponds to the 6.5 Mhz.
This is of course much more tedious and less accurate than with the script above and you need a sg that can sweep, but you get a first impression and it is less tedious than to write down the measured values..