With a horizontal loop around the roof, RFI is a problem for me. The RadioShack One-Outlet Electronic Equipment Surge Protector with 40dB Noise Filter 61-2430, $11.49, blocked RFI out of a new TV. Up to 40 dB noise reduction between 100 kHZ and 100 mHZ is claimed for the unit. http://support.radioshack.com/support_supplies/doc69/69038.pdf John, K7JG