“Is it possible that the software got crazy and didn't enable any section in the LPF filter?
73,
奥辞箩迟别办”
It’s unlikely that the software is doing anything wrong. It’s more likely that some piece of hardware has a problem in order to figure that out. We have to divide this somewhere and decide whether the problem is on the left side or the right side. With your voltmeter, unable to measure DC voltage properly in the face of RF, this is going to be a little more difficult and may require the scope.
But the first problem is probably to split this into modules and figure out where the issue is : with the transformer or beyond that.
