[Drake] R-4C static crashes?

[W7DAH]

Have an R-4C (2 actually) and one has developed it's own static storm.
Currently only distracting / mildly annoying. Source seems internal rather
than external because R-4C number 2, running side-by-side has no such symptom.
What is SUSPECT number one which I might address / attack first, please?

Thx
--
Don - W7DAH
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