I have made the transition from Tesla coiler to Ham radio operator and find myself suffering from a guilty conscience. I'd hate to retire my coils to the dust of the tool shed indefinately, but I worry that I will be unable to show my face at the local club meetings if I continue to fire them up. What sort of QRM do they cause? Is it at least confined to harmonics of the resonant frequncy, or does it pretty much just bulldoze the spectrum?