Date: Tue, 5 Nov 2002 23:11:43 -0500

Author: "Dick Heckathorn"

Subject: RE: Flame tube

Post:

I use the type of plastic that comes on Easter baskets to seal the end
that the speaker is fastened to. I use rubber cement to seal it to the
enclosure around the opening.

Dick

"Science is nothing more than learning how to communicate with nature in
such a manner that it will talk back."

Helping teachers who facilitate, motivating students who learn.
Dick Heckathorn 14665 Pawnee Trail Middleburg Hts, OH 44130
440-826-0834
Physics Teacher CVCA 4687 Wyoga Rd Cuyahoga Falls, OH 44224
330-929-0575 VM 120


-----Original Message-----
From: owner-tap-l@listproc.appstate.edu
[mailto:owner-tap-l@listproc.appstate.edu] On Behalf Of Bill Alexander
Sent: Tuesday, November 05, 2002 4:25 PM
To: tap-l@listproc.appstate.edu
Subject: RE: Flame tube

I believe that if you enclose the area behind the speaker, it will
greatly
reduce the sound pressure in the tube, since the enclosure will not
allow
the speaker cone to move freely. What I did on ours when it caught fire
was seal the end w/ a section of plastic bag, flexible enough that the
sound goes right through.

>
>Improvement suggestion:
>
>It was suggested to me that I might make an airtight enclosure for the
speaker
>so that no gas leaks through the surrounds. 'Sounds like a good idea
because
>gas definitely leaks out there (I've lit it) and there is noticibly
less
>flame-height at the speaker-end because of this leak. My thought is to
use
>a cylindrical piece of tupperware, cut the bottom out, mount one end to
the
>back of the speaker, and put a rubber diaphragm over the other end.
This
>would also allow you to slap the rubber to do a 'pre-demo' buildup if
you
>wanted.
>


>>
>>
>>I'm interested in building a flame tube -- basically a large "gas
grill"
>>with a speaker in one end that shows standing waves by the
corresponding
>>heights of the flames. I have a student who has the know-how to build
>>one, but we'd appreciate any information & advice -- or, best of all,
>>some plans! In particular, we're wondering whether anyone knows
anything
>>about choosing the hole spacing and diameter.
>>


Bill




Bill Alexander Excuse me if I ramble,
Physics Dept. but I drive a Nash.
Humboldt State University
Arcata, CA 95521

phone: (707) 826-3212
e-mail: wca1@humboldt.edu
http://sorrel.humboldt.edu/~phyx/faculty/alexander.html



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