[RFI] RFI source found!

[Jim Brown]

On Sat,8/27/2016 9:15 AM, Brian Davis wrote:
>   A quick survey reveled a Hitachi 7.2 to 14 volt Ni-Cad/Ni-MH (model UC-14VFA) cordless drill battery charger that was plugged in all the time.  Testing showed RFI anytime the charger was plugged in, battery or not caused serious RFI.

Yet another example of a switch-mode power supply (SMPS). THIS IS NOT 
NEW, GUYS! SMPS are a VERY VERY VERY VERY common cause of RFI. I've 
posted this link here at least a half dozen times. Virtually every wall 
wart, line lump, computer power supply, and battery charger IS an SMPS. 
Most equipment that plugs into the wall contains an SMPS.

http://k9yc.com/KillingReceiveNoise.pdf

BTW -- there's a very high likelihood that the charger for the new drill 
you bought him also is an SMPS, and that you will hear it on other 
bands. One of the characteristics of an SMPS is that the RF trash it 
produces is stronger on some bands than others.

73, Jim K9YC

73, Jim K9YC