Re: Secondary Q

["Jim Lux" <jimlux-at-xxxxxxxxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

I'd say, looking at some of the waveforms that folks have published from
time to time that the Q of a typical TC is around 10-15.  Obviously, once
the spark forms, the Q drops dramatically...

But, by all means, pour on the coal...

Tesla list wrote:
> 
> Original poster: "Kennan C Herrick" <kcha1-at-juno-dot-com>
> 
> 2.48?...A Q of 2.48??  I am shocked!...shocked!  Here, during all these
> years of thinking about Tesla coils--over 60 of them, I will have you
> know!--I've been under the misapprehension that Tesla-coilers depended
> upon, cherished and highly valued...resonance!  But no..., no..., no...
> Q?...who needs it?  Resonance, even...who needs it?  With the power and
> voltage of a Grand Coulee or a TMI or even, in better times, of a
> Chernobyl, coupled thru a vast pile of pole pigs, who needs resonance?
> 
> I've always likened Tesla-coilers to those profound Asian monks who
> ritually bong upon their magnificent bronze gongs.  But no, most of you
> just pour on the coal.  While I strive to maximize output while
> minimizing input, your goal is to maximize output while maximizing input.
> 
> Who cares if you can fry eggs on your secondaries?  It keeps the shop
> warm.  Q of 0?  Not a problem!
> 
> Disillusioned in California,
> 
> Ken Herrick
> 
> On Sat, 04 Nov 2000 17:21:12 -0700 "Tesla list" <tesla-at-pupman-dot-com>
> writes:
> > Original poster: Terry Fritz <twftesla-at-uswest-dot-net>
> >
> > Hi Kennan,
> >
> > Disruptive coils have very low over all Q.  My big LTR's is about
> > 2.48 as
> > shown in the graph at:
> >
> > http://63.229.238.62/TeslaCoils/Misc/BigLtr-VvF.gif
> >
> > This is how we can load up streamers and do other frequency altering
> > things
> > and still get good output.
> >
> > I think the discussion of Q really comes down to losses in
> > disruptive
> > coils.  Since I used Sonotube, my streamer length may be about 5%
> > less than
> > if I had used PVC.  A surprising amount of power is going into
> > heating the
> > cardboard.  As you note, our voltage amplification is by impedance
> > transformation rather than pure resonant ring up.
> >
> > Of course, 5% is not a super big deal but the loss is surprising. In
> > a
> > humid place, it may become a real problem.  In a CW coil, heating
> > could
> > become a real issue since the tube could get hot enough to burn if
> > you are
> > really pushing a lot of power into the system.  Q is far more
> > important in
> > the CW case.
> >
> > BTW - Tesla had some nice CW coils too in teh 1900's that ran off
> > high
> > frequency alternators.  However, unlike our disruptive coils today,
> > he
> > would not recognize most of the parts of today's solid state
> > machines.
> > Tubes were the "modern" thing in his time so he would not have a
> > problem
> > with that  ;-))
> >
> > Cheers,
> >
> >       Terry
> >
> >
> > At 01:30 PM 11/4/2000 -0800, you wrote:
> > >There's been a bit of discussion of secondary Q recently that leads
> > me to
> > >ask how all you 19th-cy. spark-gap types (the vast majority!)
msnip...