well when i bought my terrova i bought a 570 bird had to run wire thru shaft to stop the problems. now i have bought a 587 and ran the new trans thru the shaft so as not to have this prob, but i was wrong. tried every setting on noise filter too. gonna have to call em n geg one sent out to me. funny thing, it does not happen immeadeatly, always the second or third trip out that the interferance starts....