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Re: Singing like a banshee
Tesla List wrote:
>
> >From dwt-at-efn-dot-orgTue Jul 16 21:49:45 1996
> Date: Tue, 16 Jul 1996 15:30:53 -0700
> From: David Trimmell <dwt-at-efn-dot-org>
> To: tesla-at-pupman-dot-com
> Subject: Re: Singing like a banshee
>
> Chip wrote:
>
> "[ I'm going to put this in the safety FAQ if/when I get to that
> section.
> It'll go under the "legal safety" section --
>
> When I first started getting into tesla coils, I called the FCC. The
> guy
> didn't know much about them, but the one point he made that was clear
> was that modulating a coil (and thus any output RF waves) is illegal.
>
> If you are going to do this experiment, I suggest constructing a
> faraday
> cage for your apparatus. -- Chip ]"
>
> Chip, all,
>
> My understanding is that, technically speaking, all TC's are
> transmitters of radio frequency emissions in the FCC regulated
> spectrums. Granted that a well tuned TC is a very inefficient
> transmitter, as the majority of the energy is being dissipated as
> electrical discharge, but nonetheless, a transmitter. My understanding
> of the FCC Regulations is that ALL transmitters must be licensed and
> operate according to the set standards. Speaking to a FCC official
> about voice modulated TC's would be like talking about pirate radio. If
> anybody here has had any dealings with the FCC good or bad I would be
> interested in hearing about it, especially in relation to public
> displays of TC's. My belief is that operating a TC in a Faraday cage is
> the only "legal" way to do so. If I am way off base here please let me
> know. Thanks all.
>
> David Trimmell <dwt-at-efn-dot-org>
Dave, Chip, All
The real rub with the FCC and neighbors is the very specific FCC mandate
in the 1930s outlawing all spark gap excited transmitters and RF
generators. (bandwidth of signal is to wide and splatter of power at
other harmonic frequencies too broad.)
We are all illegal! But who's watchin'! The FCC just recently has made
a public statement that they will no long investigate individual RFI
complaints. (read this amazing statement in , I believe Radio
Electronicss a year or two ago!) Reason.... Low budget, low manpower and
too many complaints. It is to be settled between the complaining
parties! If there is a major disuption in com traffic somewhere they,
obviously, will step in and federally stomp the offender. For the most
part we are OK with the FCC, It is our loved ones and close neighbors
that we must gaurd and insulate ourselves against. I think a faraday
cage for a small system is an absurdity! For a large one it is just a
ridiculous expense. Apartment dweller coil builders are the most
vulnerable to complaints.
Most people have abandoned AM radio in their homes. (where most Tesla
noise occurs.) FM is only slightly affected by TCs and 90% of humanity
is on Cable TV (they are pretty well shielded from TC activity.) so TVI
is even a non-issue for most of us.
The number of major interference cases is virtually nil. I have a couple
of humorous experiences to relate regarding the old Nemesis 13KW days
here in th' lab. In one instance, It was a dry summer day and we held a
meeting at the lab. The ground was not all that good. Nemesis was run
for three period of about 3 minutes each. After the final run, we had
put the monster to bed and were dinkin' around with small coils when we
heard sirens.
The fire trucks stopped three houses down from my home and a couple of
our less attentive members, (probably figured a good fire would top
anything goin' on in the lab), loped on down to see what the problem was.
They came back with a story of how the woman who called in the alarm was
drawing sparks off here sink fixtures and was worried about electrical
problems. LESSON... Keep your powder dry and your ground system wet!
A co-worker in my company moved into a rental house diagonally across
from mine for about a year. He noted that on one occasion, he was on a
long distance phone call with his brother in Alaska (he was using a
portable cordless phone) and he heard my coil come on out of an open
window. He said that a little static was noticable and then he said I
really cranked up the power (noise level became unbearable) and the phone
hung itself up and all he got was an instant dial tone. Likewise, my
wife won a free touch tone phone (el cheapo model) at some hen party for
cosmetics and we used it for only 2 weeks until I next ran Nemesis.
Totally fryed internally. We have always had to old clunky rotary phone
of 30 years ago with the clack, clack, clack pulsed leaf contacts.
(Impossible to destroy except in a nuclear holocost)
LESSON.... Portable phones and touch tone systems can be damaged or
operate irratically around massive TC systems.
Finally, my other neighbor (next door) recently bought an answering
machine which record messages on ram (digitally) instead of cassette
tape. He started getting complaints from friends who said they left him
a message and he never returned their calls. Oops! All his measagges
started geting erased.
He wondered why he never got called when he was away. He sought my
advice as the neighborhood electrical wizard. I told him that the older
tape machines worked much better than the high-tech computer crap. He
took my advice and now gets all his messaages on cassette tape.
Lesson... Always acts dumb, but give good advice to steer your neighbors
away from suspecting you.
Identify your specific problems and solve them, but try and keep the
neighbors in th' dark about what you are doing. Big systems demand big
spaces and extra-ordinary efforts to avoid problems with other
often less tolerant and more suspicious humanity.
Richard Hull, TCBOR