RE: THOR resonance freq. measurement results

["John H. Couture" <couturejh-at-worldnet.att-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Marco -

Did you check for the resonant frequency using the JHCTES Ver 3.1 program?
The program results have been found to agree closely with tests when the
tests are done correctly. The program is available as a free download at

  http://home.san.rr-dot-com/jcouture/tesla

When using this program start by designing the secondary circuit first. This
will determine the operating frequency for the TC system. The primary
circuit is then designed by selecting the primary capacitor you want to use.
The physical demensions of the spiral or vertical coil are then easily
determined.

Methods to test for the various TC parameters are shown in my books.

John Couture

----------------------------

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, July 14, 2000 7:02 AM
To: tesla-at-pupman-dot-com
Subject: THOR resonance freq. measurement results


Original poster: "Marco Denicolai" <Marco.Denicolai-at-tellabs.fi>

Hello all (again).

I have also been measuring the primary and secondary resonance frequencies
and I
would like somebody to comment my results.

Secondary measurement
--------------------------------------
I disconnected the secondary bottom from ground and connected the function
generator hot lead to it. Func. generator cold lead heartened. Measuring the
electric field with a scope probe. Setup using long shielded cable to saty
far
from the coil. Top toroid included in the measurement..

I measured 3 resonance frequencies:

65.46 kHz
222.75 kHz
346.3 kHz

Can somebody explain the error (these are not exactly 1st, 3th and 5th
harmonics, why?) ?

I also measured the frequencies were the measured field amplitude was
halved:

65.72 kHz halved
65.46 kHz full
65.21 kHz halved

But I don't recall how to calculate Q from it. Could anybody help, please?


Primary measurement
---------------------------------

First I tried to measure primary inductor and capacitor connected as a
series
resonator, but I could only and always spot the secondary res. freq. Then I
connected them as a parallel resonator, fed them with the function generator
through a 0.1 ohm resistor and measured the resistor voltage (i.e. the
current
sourced). I wrote down the points were the current was MINIMUM.

Primary turns            Freq.              Wintesla predicted
   used                         (kHz)                        (kHz)
     9                      54                                      54
     8                      60                                      61
     7                      66     (78)                          70
     6                      70       81                          81
(there was little difference between 70 kHz and 81 kHz minimum levels)
     5                      (72)     96                          96

The numbers in brackets are a second minimum that was not so low in value
as the
first one. Below 5 turns it was very hard to detect the minimums, so I gave
up.
I am anyway interested only in frequencies near 65 kHz. It seems to me that
with
the aid of the Wintesla prediction it is easier to read the measurement
results
and to conclude that the prediction was correct. Any comments anybody?