Like a lot of us girls, I use my computers as a resource when working on receivers and amps. I've found that when working in tuners, particularly on AM, I experience significant RFI which can skew the alignments. A CPU clocking at well over 1 GHz and its data bus clocking along at over 250 MHz seems to have quite an effect on the tuners. I've moved the nearest computer 6' from the bench, but still experience the phenomenon until it is shut off. Turning off the LED monitor seems to have no effect. Disconnecting the USB mouse and keyboard, and disconnecting the speakers also does nothing, thus I'm thinking it must be the PC itself. I set a grounded steel sheet between the PC and the workbench to no avail. Has anyone found a method to shield computers effectively to eliminate this? I have two PCs in my work area and have to print manual sheets, then shut them off before undertaking an alignment. It's not the end of the world as we know it, but is inconvenient.