RF concern?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Richard W." <potluck-at-xmission-dot-com> 

Hi all,
I've searched the list for RF filters. I'm not sure whether I need RF 
filtering or not.
Currently I have a stack of variacs with each output in series with the 
secondary of a heavy filament transformer with wire that measures out to 
#8. (120vac input and 13 volts out, 650VA). The outputs are tied to 25 feet 
of shielded Firex 6/4 cable to a pig. With the cable only ( no connection 
either end) each strand measures around 840pF to the grounded shield.

Do I need RF filtering?

Thanks!

Rick W.
Salt Lake