[R-390] EAC power hum

[Barry]

> I have not added an IEC compliant plug on the back of my radio. I just
> really do not want to take a chassis nibbler to the back of the radio.
>
> Ms. Tisha Hayes

This can be done without hacking the rear panel (at least on an R390A).  I 
made some simple aluminum adapter plates that allowed a Corcom (or equiv.) 
filter to be mounted inside the rear panel.  It helped to extend the 
rounding on the edges of the IEC end of the cable beyond the factory-made 
length because it lets the plug enter the filter just a bit further, but 
that was not a big deal (and would work okay even without doing that). 
Having a 90-degree IEC plug on the rear of the radio was kind of nice.

Barry - N4BUQ