[RFI] KG2V's new RFI rule of thumb...

[Cortland Richmond]

Anecdote: I was once called to a Ham EMI complaint involving one of my 
then-employers pole and wire-mounted subscriber equipments;  a harmonic 
of its  1.024 MHz clock  was interfering with a 2 meter repeater the 
Amateur wanted to hear.  A predecessor had left *42* ferrites on the 
inputs and subscriber drops, which MIGHT have made *1dB* improvement.

Back in the lab, I was able to knock it down by adding a (IIRC 39 Ohm) 
resistor to the clock line on the legacy single-sided board.

On 8/24/2013 1305, Charlie Gallo wrote:
> I've come up with a new rule of thumb:
>
> If the manufacturer puts a ferrite on the leads of a device, it isn't enough, and the item is an RFI bomb
>