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Re: oil filled resonators
>>From ed-at-alumni.caltech.eduSat Oct 12 13:12:26 1996
>Date: Fri, 11 Oct 1996 18:13:29 -0700 (PDT)
>From: "Edward V. Phillips" <ed-at-alumni.caltech.edu>
>To: tesla-at-pupman-dot-com
>Subject: Re: Gap Dwell Times (formerly: Beating Solved)
>Re: Oil immersed coils.
> Has anyone in this group experimented with same, and if
>so, what were the results. There certainly is precedent, going
>back to Mr. T himself. Would be very much interested in any reports.
>How about the Richard's???
>Ed Phillips
Ed,
I'm in the process of building a large vacuum tube driven TC for a
commercial client right now. Last year I fabricated an oil filled resonator
for this project consisting of a 16 inch diameter fiberglass form
close wound with #8 AWG thermaleze copper wire to a length of 5 feet.
This coil is positioned coaxially inside a 200 US gal steel cylindrical
drum and filled with VoltEsso 35 oil. A large oil filled shedded
ceramic bushing (12 inch outside diameter and 30 inches long, 8 inch
oil filled hollow around a 1/2 inch copper waterpipe HV buss inside) sticks
vertically out the top side of the horizontal drum at one end making it look like
the smokestack on a steam locomotive. A spun aluminum terminal tops the
bushing as the HV output. Inside at the other end is a 15 turn flat copper ribbon
spiral primary. I have little test time on this device as yet, and
only with a modest vacuum tube exciter oscillator. I am not generally
pleased so far with the Q which is lower than from a similar coil in air and
without metal walls around. Note also that the surrounding metal
container is lossy mild steel, not silvered copper. There should be both
eddy current as well as I2R losses in the skin depth. Operating
frequency is 100 kHz.
I expect to be pushing as much as 15 kilowatts CW into this resonator within
the week with a power oscillator I am constructing in my lab now. It uses three,
EEV, BR1160 triodes in parallel, 5 kW plate dissipation each. I have no
opportunity or plans at this time to excite the big oil filled
resonator with a spark gap oscillator, but will post my results
with it CW excited on the list soon..
By the way, this 15 kilowatt vacuum tube oscillator is only going to my client
on temporary loan. When I get it back I plan to use it with a normal
air insulated secondary resonator for my Saint Elmo Burger/Dog party and
Teslathon. We'll be able to cook weenies on the end of bamboo poles in a
solid sheet of hissing flame like Mark Barton refers to as 'the welding torch from
Hell'. I also have hopes that my big coil might be operational for this gig. It
will probably be next spring at my new hobby farm property and vastly
improved Tesla shop facilities near Shelburne, Ontario, to which I am
moving in three weeks. All fellow coilers are welcomed. Stay tuned on this
channel for where and when! : )
Regards,
rwstephens
<If its less than 1.2 kilowatts its filament current!>