Re: Variation of secondary Q

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Paul,

>
>No sign of any 60kHz breaking in.  If you can resist the temptation
>to average multiple traces, we'll still get enough signal for the
>F and Q extraction, and maybe we will also see a whiff of 60kHz
>coming through too. When you average over 128 shots, the 60kHz adds
>incoherently so its amplitude is attenuated by sqrt(128), a factor
>of 11.  Don't worry about the trace being noisy.  The least-squares
>process by which we match A * cos( w*t+p) * exp( -r*t) to the
>waveform ensures that the noise (and vertical quantisation error)
>is reduced by a factor
>  sqrt(samples_per_trace) = sqrt(10,000) = 100.
>Further, I can chop out any FFT components outside of the range
>Fres +/- BW, thus removing the low frequency RC pedestal and most
>of the other bits of noise.

>Can we have a CSV of a single shot ringdown?

Ok, so you like noisy signals and can get the data you want and more out of
them (your pretty good at this stuff ;-))  I just put in a new florescent
light in the play room (conventional 60Hz ballast type right above the
coil) so maybe you can see the 60Hz off it.

http://hot-streamer-dot-com/temp/Qvar/Tek00005.gif

http://hot-streamer-dot-com/temp/Qvar/TEK00001.CSV

I tried my Q = Vtop/Vin thing and I don't like it.  It does give a reading
and all but there is a lot to go wrong.  I pulled this data last night:

http://hot-streamer-dot-com/temp/Qvar/BOOK2.XLS

Since Paul is a UNIX guy and might not be able to read Windows Excel, here
is a plain data file.  Terry has a new SUN Blade 100 computer so I am sort
of a UNIX newbi too :-))

http://hot-streamer-dot-com/temp/Qvar/Qtest.csv

Hope that works...

I think the voltage here is proportional to Q (~216).

So I think you were right Paul,  The step response is the way to go.  I
figured out a way (I think) to fix the tiny signal levels.  Instead of
using the signal generator that only does a tiny 20 volt P-P, why not just
charge the sucker up to 1000 volts and let an IGBT short it to ground.  50X
the signal then :-))  Either the plane antenna or the current pick should
work fine then.  I can either use a rectified MOT or fire up the old Fluke
HV supply (needs work).

I have been looking at the "NEW!!" Tektronix TDS3GV plug in to enable
RS-232. As fate would have it.  The sales guy looked me up today...
Although the company is too po to buy anything, he correctly figured "I"
was still buying ;-))

""""""""
New TDS3GV Module: Combined GPIB/RS-232/VGA
This new module combines the function of two modules previously available �
TDS3GM and TDS3VM � at the same low price as one of the previous modules.
Included with the TDS3GV module is a free 30-day demo version of WaveStar
data capture and analysis tool and VocalLink voice control software for
oscilloscopes along with a programing guide.
""""""""

I am not sure WaveStar software will take the data we need at intervals but
apparently the VocalLink thing can "yell" at the scope to do it :-))  I can
see that...  A second PC is programmed to say "It's 4:20 PM March 18th, so
take a reading NOW you $%&^#& thing!!" :o)))  But it comes with the
"programming guide" which details the commands to give it.  Time to pull
out QuickBASIC ;-))  If they do work, I guess our tests have to be within
the 30 days before I have to reload the old computer ;-))

So I guess I should get the TDS3GV...  Probably a load of fun there.  I
suppose I could network the data so you could pull it directly...  Still
thinking here  *;-)

Cheers,

	Terry