My Computer Monitor produces a lot of line noise when recording through a mic or an acoustic guitar pickup. By moving around and aiming the mic/guitar in different directions I can greatly reduce the noise that is picked up but not eliminate it totally. And If I turn the monitor off, I have a very clean, noise free sound.

I've been fighting RF interference in a PA system at our church. The offending station frequency is 1510 KHz (which corresponds to a 1/4 wave distance of 162.91 ft).

There are a lot of postings on the topic of RFI at various audio websites. I'd like to include my version in case somebody else gets driven nuts (like me) trying to find just where the problem is in their system. I transfer vinyl and tape to CD. I'd like to remaster or master for real bands but everything in due time.