Re: Waveguide TC

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Waveguide need not be made of a conductor (and, for that matter, Indium
oxide is a conductor and transparent and is used on LCDs for that very
reason).

A glass fiber cable is a waveguide

One can also propagate a wave down a dielectric rod (used in polyrod
antennas).

All you really need is an  index of refraction discontinuity to make a
waveguide.

There are also very nifty waveguides where the wave propagates on the
outside of the dielectric rod in free space (very low loss at mm
wavelengths..)

One could certainly propagate a wave through a tube filled with an easily
ionizable gas.

It might not be efficient. It might have other strange properties, compared
to "conventional" waveguide, but it might be useful, just because of those
properties.  For instance, media in which there is significant dispersion
(i.e. propagation velocity is a non-constant function of frequency) are
quite useful.  A gentleman by the name of Newton made good use of the
dispersive properties of glass, for instance.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, December 15, 2002 12:05 PM
Subject: Re: Waveguide TC


 > Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<dhmccauley-at-spacecatlighting-dot-com>
 >
 >
 > Yeah, if you had transparent aluminum ! ! ! !
 >
 >
 >
 >
 >  > Is there a possible use for a waveguide -filled with a suitable gas at
low
 >  > pressure- as a discharge lamp like a neon or fluorescent tube?
 >  >
 >  > Jolyon
 >  >
 >  > ----- Original Message -----
 >  > From: "Tesla list" <tesla-at-pupman-dot-com>
 >  > To: <tesla-at-pupman-dot-com>
 >  > Sent: Saturday, December 14, 2002 3:51 AM
 >  > Subject: Re: Waveguide TC
 >  >
 >  >
 >  >  > Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
 >  > <dhmccauley-at-spacecatlighting-dot-com>
 >  >  >
 >  >  >  >  > There are very high voltage potentials inside waveguide and
 >  > waveguide
 >  >  > arcs
 >  >  >  >  > are probably the wicked-est arcs I've ever witnessed.  This is
 > the
 >  >  > reason
 >  >  >  >  > high power
 >  >  >  >  > waveguides are usually pumped full of pressurized air or
 > nitrogen.
 >  >  > I've
 >  >  >  >  > worked on transmitters putting out over 1.5 MW of power at
S-Band
 >  >  > (3-3.5
 >  >  >  >  > GHz) and you should
 >  >  >  >  > see what these arcs do to the internal portions of the
waveguide.
 >  >  >  >  >
 >  >  >  >  > Dan
 >  >  >  >
 >  >  >  > Of course, the damage depends on how much average power is
 > available.
 >  >  >  > Note that every high-power radar system of which I am aware has a
 >  >  >  > "waveguide arc detector" to protect the system from damage from a
 >  >  >  > continuing arc.
 >  >  >
 >  >  >  > Ed
 >  >  >
 >  >  >
 >  >  > Yes, but waveguide arc detectors are almost always placed close to
the
 >  > tube
 >  >  > itself.  Any waveguide arc downstream especially through long-length
 >  >  > flexguide
 >  >  > can be subjected to arcs of long duration causing lots of damage.
In
 > this
 >  >  > case, the only way to detect an arc is through detected reflected
power
 >  >  > going back
 >  >  > to the tube or wherever the reverse power couplers are.
 >  >  >
 >  >  > Dan
 >  >  >
 >  >  >
 >  >  >
 >  >
 >  >
 >  >
 >  >
 >  >
 >
 >