Jerry,
VBW in the simplest form is a low pass filter after the detector to take out high
frequency noise.? If overdone you start filtering useful information as we are
dealing with signal over time.
Close analog, Take a simple half wave power supply look at it with a scope.
your see DC, make the filter cap smaller so that it stops filtering the 60hz
and you start to see bumps then humps and half sine waves.
Same happens with the log detector in SAs.? You measure a point frequency and if the?
filter is narrow it doesn't register it because the filter saw it as a fast event and its
eliminating them.
You also get that with noise as averaging noise tends to make an average of zero
(if the noise is truly random).
Allison
