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Re: Believe it or not
Tesla List wrote:
>
> Original Poster: Travis Tabbal <bigboss-at-xmission-dot-com>
>
> They recently started enforcing the Amateur bands. There were a few
> articles in QST and on the ARRL web site. I doubt TCs are in danger, the
> RF doesn't extend very far on my coil anyway. I would think that most of
> the energy is going into the streamers rather then making RF. With line
> filters and a little caution you would probably be within the limits
> anyway. Just be carefull and take action if your neighbors complain to
> fix whatever is bothering them so they don't call authorities.
I talked to the Bureau Chief of the Atlanta Region office last
weekend at the Lawrenceville, Ga hamfest. His name is escaping me
at the moment. He has been the driving force behind the very
welcome resumption of amateur radio enforcement action. He is also
pushing enhanced enforcement in other areas. While hard core
libertarian at the core, I very much welcome this effort to clean up
the bands from the lids and pirates. One should be aware that the
Atlanta region (listening station at Powder Springs, Ga) is getting
the most attention now.
Regarding RF, don't underestimate the propagation of the RF energy
your coil makes. With a fundamental frequency in the VLF range with
harmonics extending to the low MHZ range, any coil is generating RF
that propagates via both ground wave and skip very efficiently. The
only partially saving grace is that the TC has a fairly poor
radiation efficiency. I could hear my old, fairly small coil
(12-18" streamers) for miles on an AM radio and probably much
farther on the SW bands.
Not trying to be a wet blanket, just suggestion that we not
underestimate the effects our coils can have. Discretion is
required.
Interesting story: In about 1989, Dale Heatherington (co-founder of
Hayes Modem company and the technical brains behind the company)
designed our local packet radio club a 56kb direct RF modem. We
sold kits to pay for building a high speed RF network across Ga long
before the Internet was kool. Dale lived in north Cobb county,
perhaps 10 miles from the FCC Powder Springs monitoring station.
His modem generated an RF signal with a 75khz bandwidth. Sounded
like interstation hiss on a regular narrowband receiver. All very
legal on the UHF band segment he was using. Literally minutes after
his first on-air test at about 100 mw, with bursts lasting about a
half second, a friend of his who worked at the monitoring station
called him wanting to know what the hell kind of signal he was
generating! This should give some idea of how effective the
monitoring station can be in pinpointing radiators when they want
to.
John
--
John De Armond
johngdSPAMNOT-at-bellsouth-dot-net
http://neonjohn.4mg-dot-com
Neon John's Custom Neon
Cleveland, TN
"Bendin' Glass 'n Passin' Gas"