Hi , I've produced this simulation of a superhetrodyne radio receiver. I'm pretty sure it's solid for the most part but im getting a list plot error

ListPlot::lpn: {{{1.,0.},{2.,0.00104953},{3.,0.00417391},{4.,0.00897666},{5.,0.0144962},{6.,0.019545},{7.,0.0231284},{8.,0.0247955},{9.,0.0247967},{10.,0.0239932},<<31>>,{42.,0.0875546},{43.,0.0860275},{44.,0.0862261},{45.,0.0881567},{46.,0.091152},{47.,0.0941063},{48.,0.0958663},{49.,0.0956389},{50.,0.0932715},<<385951>>},<<3>>,{}} is not a list of numbers or pairs of numbers.

I'm having a total nightmare trying to make sense where my mistake is. Any help would be appreciated.

Code below, Thank you.