Hi all,
while the Seibt-Experiment is not spectacular, in the sense of making
"big bangs or sparks", it's quite rewarding, to show the behavior of a
resonator, by _very basic means_ of provoking corona discharges, along a
winded wire, to speak: a very thin and long coil plus a corona wire
along it (H/D=38). If I'm not mistaken, you won't find a lot about
googling the "Seibt coil", except perhaps at Antonio de Queiroz site:
http://www.coe.ufrj.br/~acmq/mk95939.jpg
I made my own Seibt-Coil, winding the 4187 turns for one coil, with my
friend Andi within one hour, (including 50% beer pause, having a good time
;-)). We made 2 of the coils, to be seen at:
http://home.datacomm.ch/k.schraner/Dscn1740k.jpg
The feeding circuit was in very traditional style 19th century mode, first
following the maggie-configuratin of Antonio's display, with a 158-turn
secondary. However, in practice it was discovered, simple
autotransformer+galvanic coupling proved more effective, as seen in the
schematic diagram at:
http://home.datacomm.ch/k.schraner/Seibt_schema_3.gif
...which I have realized as:
http://home.datacomm.ch/k.schraner/Dscn1760c.jpg
In the picture, the spark gap, set fairly wide at about 20mm, is seen
firing. This gap needs to be covered, and the room totally darkened, in
order to observe the faint corona phenomena along the Seibt-coil. But the
human eye can easily adapt, and see it nicely. Unfortunately I've not yet
a convincing picture of the coil in operation, due to using a digital
camera, which is not allowing manually setting the needed long exposure
times. Anyway, here is, what I've currently available:
http://home.datacomm.ch/k.schraner/Dscn1750b.jpg
The ring-shaped figure at left is corona at one of the Leyden-jars. You
may be able to distinguish the 5 corona zones along the coil at right.
This is to be interpreted as 2 full waves along the coil (= 8 quarter
waves), as made plausible in this diagram:
http://home.datacomm.ch/k.schraner/Stehwelle5b.jpg
The primary resonance had to be tuned to ~2.3MHz, which corresponds nicely
to 8 times the measured 287kHz quarter wave base frequency of the
Seibt-coil. It is also possible to generate 7 glowing zones on the coil,
by tuning the primary to ~3.5MHz, corresponding to 3 full waves along it.
Well, I hope bringing better corona pics, when having finished and
developped the film on my conventional camera, which allows manually set
long exposures...
Best regards,
Kurt Schraner