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Re: truly massive Tube Coil
Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>
Tesla list wrote:
> Original poster: "sundog by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> Hi All!
> It's just a sickness, I tell you. Coilers have some measure of
> insanity, a little demon on our shoulder that whispers, "Phase in another
> NST. Crank the Variac to 140v out...Wind an 8" coil...good....now buy a
> It was that little demon that whispered to me, "You *NEED* that GU10A
> transmitting tube...." So I have coming to me a 10kW russian transmitting
> triode. This thing moves so much power the anode (plate) must be kept in a
> water bath, in addition to the forced air cooling of the base of the tube.
> The filament alone pulls more power than most coiler's NST powered coils.
> The tube can crank out over an amp at 8kv, and it can run up to 26mhz (not
> important). The quad 833 coil is truly a powerful device. It melts
> drywall screws and heats up tungsten-carbide to white hot for crying out
> loud, and that's only at 2kw input (of 3kw it's capable of handling for 15
> min or so). I can very well imagine what 4x that power will do.
> Much designing, planning, and scrounging to be done! My #1 enemy with a
> coil of this power level is *HEAT!* The quad 833 heats the primary coil to
> scalding hot in just a few minutes. Not to mention the fact that the FCC
> will disapprove *very* highly of an unlicensed transmitter running at many
> thousands of watts....on a broad band no less......Looks like I'll be
> choking and tuning and suppressing *everything*.
WHy would it be broadband? It's essentially a power oscillator...
You're also an unintentional emitter, no? (you incidentially radiate, but
your intention wasn't to build a transmitter, was it?)
15.5(b) you can't cause harmful interference, and you've got to accept
interference. Radiating power is not, per se, harmful..
15.5(c) you can operate, but if they (FCC) tell you to stop, you have to.
15.5(d) prohibits Class B damped wave INTENTIONAL radiators. No hanging an
antenna (i.e. intention to radiate) on your spark gap (damped wave) TC!
15.13 Manufacturers employ good engineering practice to minimize risk of
harmful interference. Use filters, but you don't have to go hog wild.
15.23 Home built.. Quantity < 5, personal use, don't have to make
measurements to verify compliance, but still have to use good engineering
15.29 The FCC may want to inspect it, your design information, and any
documentation you might have.
15.33 (b)(1) If you measure, you need to measure up to 30 MHz.
15.109(e) use the limits in 15.209
15.205 This is a list of frequencies upon which an INTENTIONAL radiator may
not operate, but can emit spurs. Since your Tube TC will only be emitting
spurious signals, this probably isn't relevant, but, to be a "good
neighbor" you'd want to avoid these frequencies: 90-110kHz (Loran is at 100
kHz), 495-505 kHz (distress frequency at 500 kHz)
15.209.. here's the actual radiation limits..fields in microvolts/meter
9 kHz to 490 kHz... at 300 meters distance, field <2400/F(kHz)
490 to 1705 kHz at 30 meters distance, field < 24000/F
1.705 to 30.0 MHz at 30 meters, field < 30 uV/meter
You could probably ball park the field calculation.. You're gonna be in
the near field at 300 meters, so you need to use the magnetic dipole field
equations. Figure a current of 60-100 Amps...
> Take care everybody! Comments, suggestions, snide remarks welcomed! Flames
> diverted to /dev/null
> Shad (Sundog)
> G-2 #1203
> "To call someone crazy just shows
> you can't understand their views on Life."