[Lowfer] Active Whips

[JD]

>>> While battery power will help with signals that come in through the 
>>> power system, it will do no good with  signals coming in on the antenna 
>>> coax shield. I found that was where much of my noise entered the system 
>>> .... I also have chokes in all my power lines and data
line entering the lab and that helped, but not as much as the coax chokes.

That's why I mentioned isolating the coax shield from the radio ground with 
a transformer when there are connections to the outside world (meaning, 
beyond the four wheel Faraday cage) other than the antenna itself.  What a 
person encounters in a situation like this is not strictly common mode 
conduction, but more a question of ground loops, regardless of where the 
signals are first being picked up.  An effective choke will help either way, 
fortunately.  It boils down to whether the radio's ground connection can 
"see" itself as being the reference ground, or whether the radio is just the 
middleman in a bigger loop, so whatever you can do to break up those paths 
will probably help.