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FW: In vs. Out [small magnefier ]
From: richard hull[SMTP:rhull-at-richmond.infi-dot-net]
Sent: Monday, July 21, 1997 1:47 PM
To: Tesla List
Subject: Re: In vs. Out [small magnefier ]
At 03:20 AM 7/21/97 -0500, you wrote:
>
>From: DR.RESONANCE[SMTP:DR.RESONANCE-at-next-wave-dot-net]
>Sent: Sunday, July 20, 1997 6:21 PM
>To: Tesla List
>Subject: Re: In vs. Out
>
>Hi Rich:
>
>Was wondering if anyone in your group ever tried to drive a small magnifier
>with a high power vacuum tube setup? I have an 803 with matching 3,000
>volt, 1.2 ampere power supply and matching filiment xmfr. I thought in
>might be fun trying to drive a small magnifier/resonator setup. I have in
>mind an 12 dia. sec coil closewound with #6 AWG and a 20 in. dia. primary
>of 30-60 turns with tuning taps. This sec. coil to be about 24 inches
>long. Resonator coil would be a 24 inch long winding of #14 AWG 3 kv PVC
>insulated wire -- closewound. Perhaps a 24 x 5 toroid on top of resonator
>and a small toroid of 1 inch dia. copper tubing atop the driver sec. coil.
>I'm not looking for spark-excited performance but thought a nice 36-48 inch
>discharge would be a good starting point.
>
>Comments or suggestions from you or John Freau most welcome.
>
>DC at DR.RESONANCE-at-next-wave-dot-net
Dr. R
Any vacuum tube used in a magnifier situation would have to be used as a
true switch and not as a classic oscillator with feedback. This leaves true
vacuum tubes at a great disadvantage as they can handle the volts, but not
the amps. (for larger systems.)
John Freau's notes on his use of the tubes are well taken. There is a lot
of dielectric heating and other losses associated with oscillating tube systems.
In the book "Pulse Generators" 1948, a whole chapter is devoted to hard
vacuum tube pulse circuits. The 304TL is held in high regard in this
discussion. The real advantage of such tubes is they can be controlled
easily for longer on times than H2 Thyratrons and might supply a very
distinct edge in very small magnifier systems.
I have not physically investigated hard vacuum tubes in magnifier systems.
Richard Hull, TCBOR