[R-390] line filter for EAC R390A

[Barry]

> The 390/390A is not very susceptible to RF interference from crud on 
> the power line -- most objectionable interference comes in on the 
> antenna leads -- so doing without the filter entirely will be very 
> unlikely to degrade performance, unless you routinely run your radio 
> off a square-wave inverter or otherwise feed it god-awful dirty 
> power.  I consider it a best practice to replace the line filter with 
> a modern one, but I would not hesitate to remove it altogether, 
> confident that I would never be able to tell the difference in use.
> 
> Best regards,
> 
> Don

I ran one of my R390As without a filter for a long time (until I replaced it with a modern line filter).  It might have responded to light switches a bit more than one with a good (read: modern) filter, but other than that, I doubt it made any difference.

Barry - N4BUQ