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Hi Dave, Fortunately, Tesla coils are relatively poor radiators at their relatively low operating frequencies because their "antenna" is so small relative to their wavelength. However, the peak power in disruptive coils may be hundreds of kilowatts or even megawatts, so it doesn't take a very efficient radiator. Tesla Coils do radiate significantly at higher frequencies due to the spark gap in the primary circuit and the streamers coming off the topload. The negative resistance characteristic of a spark gap shock easily excites parasitic inductances and capacitances, creating VHF and UHF "hash" that can be quite significant near an operating coil. While radiation from the primary spark gap can be reduced somewhat by using relatively large ferrites on the leads going to the spark gap, you're pretty much stuck with the stuff coming off the secondary. And, because of the higher current, power arcs to ground radiate significantly more than air discharges. Once you're sure they won't kill you, you may want to try doing some Tesla Coil experiments with your (former?) friends in the club to see if you can get any actual radiation measurement data... :^) Best regards, Bert
: 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?
:
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