[RFI] Galaxy Grow Light Ballast Update

[Jim Brown]

On Mon,2/1/2016 9:08 AM, Hare, Ed W1RFI wrote:
> I have seen filters for both the load and lamp side, so you may need to try both.

Hi Ed,

In my experience, conventional filters on the line side are less 
effective (often ineffective) if the mechanism is common mode. Remember 
that the definition of common mode for us is very different from that in 
the AC power world, where they are talking about voltage between neutral 
and green, and we are talking about current longitudinally along the 
cable. Indeed, the RF current is often on the Green wire (thanks to 
improper or missing bonding inside the noise source), and the Green wire 
goes right through commercial filters.

Our definition is what radiates, and in my experience, is most 
effectively suppressed with a multi-turn ferrite choke with all three 
conductors passing through the ferrite.

73, Jim K9YC