Al Arduengo wrote in message

Out of curiosity, why doesn't this noise show up on my FM/AM that the
truck already has? Is it that the noise and its' harmonics lie in
the same band as sw?

MW is just as prone to noise as SW if you listen to weaker stations.
Maybe more so. The reason you don't notice it on that radio, is it has
a properly designed and mounted antenna system. MK