[R-390] Filter testing

[quartz55]

Well, my first attempt at measuring the 2K filter, 4VP-P input (something more than 1V rms) gives me about .008VP-P out.  That's over -50db loss.

I do have the 82pf caps in and out, 100K in series in and 100K load. I'm assuming the caps resonate the coils in the filter, but I'm not sure what the values of the var caps I have on them are, they may be a bit small.

I can feed the filter with the service monitor at 455 and at the same time measure the output on the service monitor's scope.  It has a resolution of .01/.1/1/10V/div vertical.  So it should easily measure the required roughly .25VP-P out with 4VP-P input. My Tec 545 only has .05V/cm resolution min.

I can even sweep the SM output from 450-460, but that gives me a funky output on the scope, it may be sweeping too fast, I can't regulate that.

Given that the resistance of one side of the coils to ground is around 25-30Meg on the Fluke, it registers high loss in the R390A and the test fixture shows 50db, I'm going to pull it apart.  I need the practice anyhow.