[R-390] line filter for EAC R390A

[2002tii]

Tisha wrote:

>What I have done is to replace the line filter with a hospital grade Corcom
>filter like a 3EHQ series   http://www.corcom.com/Series/Medical/HQ/

To put things in perspective, the maximum leakage current to ground 
of these Corcom units at 120 volts/60 Hz is 2 uA -- 2500 times less 
than the amount that will trip a US household GFI.

>When the R-390A was designed the greatest sources of interference would be
>from other radio equipment or radars, the occasional fluorescent light
>fixture or generator noise. Today it's computers, computers, computers, BPL,
>wireless Ethernet, X10 home appliance controllers and el-cheapo fluorescent
>bulbs.

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