Tesla List wrote:
> >From julian-at-kbss.bt.co.ukSat Sep 21 11:54:06 1996
> Date: Fri, 20 Sep 96 12:21:08 BST
> From: Julian Green <julian-at-kbss.bt.co.uk>
> To: tesla-at-pupman-dot-com
> Subject: Re: Illegal?
> To put my mind at rest I performed a walk test with an AM radio tuned
> to the resonant frequency on my TC.
> I performed two tests.
> Run your TC at low power to prevent spark breakout. Tune a radio to the
> resonant frequence of the coil and listen to the racket. You will have to
> move away from the coil (20m) to get a fine tune. If you are too close then
> the radio picks up the signal regardless of tune.
> Walk away from the coil, stop walking when you can no longer pick the signal
> up. For me this was only 100m. This supprised me as I thought I was in for
> a long walk.
> Run the coil and allow spark break out. The sparks will produce a very wide
> band signal. This can easily be detected on FM, the TV etc. Perform the walk
> test again. I had a shorter walk on this test, only getting to the bottom
> of my garden.
> Although the radio walk test does not give you and figures, it does tell you
> how much of a distubance your coil is causing. I do however have neigbours
> living within the affected area, they are very forgiving, and do not complain
> as long as I don't run the coil during the cup final. I generally keep runs
> short, only performing the longer runs late at night when they are asleep.
> Julian Green.
We did a similar qualitative test back in 1990 when Nemesisi was running
12,000 watts. The tuned RF portion of the coil doesn't travel far at
all. In a Tesla coil, we are looking of EMF output and not RF
transmission and that is just what we get! WE are trading one for the
other. The E fields are very intense, however, but are also short range.
Richard Hull, TCBOR