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Re: [TCML] Tuning a coil PLEASE HELP

Andrew -
I believe I referred you to Charles Hobson's tiscali website.
Please duplicate the EXACT test setups shown on Charles Hobson's website. They are 100% correct AS SHOWN.
The sketch you made of your secondary resonance test setup clearly does not match that shown on Charles' site.
Note the following:
1. The ground lead of the O'scope is NOT CONNECTED to ANYTHING.
2. The O-scope probe tip can be connected to a 10" length of wire that should be supported so it's hanging vertically about 20" away from the secondary, at least for initial observations.
3. I don't understand what you mean by "modulation"; there is no "modulation" to be seen during this test.
4. To make sure that you understand the basic test setup, and that both your o'scope and signal generator are functional, first connect the scope probe directly to the low-voltage output of the signal generator. The scope should display a sine wave that varies in FREQUENCY (how close the peaks are to each other) as you vary the signal generator's frequency. If your signal generator is of good quality, the AMPLITUDE of the sine wave should be relatively constant, regardless of frequency. If this is what you see, disconnect the scope probe from the signal generator and connect per step #2 (above).
Use the 20v output from the signal generator, and connect it directly to the bottom winding of the secondary. The ground terminal of the signal generator (usually black) is connected only to the ground terminal of the frequency counter. 
5. Set the signal generator to some arbitrary RF frequency (say 150 Khz), and adjust your oscilloscope controls until the scope clearly displays a 150Khz sinewave. Adjust the amplitude so that the peak-to-peak sinewave only takes up about 25% of the available screen height.
6. Now SLOWLY vary the frequency control of the signal generator up and down while carefully watching the scope. At some point, the amplitude (the height) of the sine wave will suddenly and DRAMATICALLY increase. You may have to re-adjust the gain on the oscilloscope to see tha maximum height. Once you have found the maximum amplitude of the sine wave, you have found the secondary's resonant frequency.
7. I wasn't able to get your sketch of your primary resonance test setup to display properly, so I don't know what your setup looks like, but again, simply duplicate the setup shown on the tiscali site. Do not add any other connections, etc.
Go back and perform steps #1 through #6, above, and let us know what you find.
Herr zapp

--- On Tue, 5/5/09, Andrew Robinson <teslamad@xxxxxxx> wrote:

From: Andrew Robinson <teslamad@xxxxxxx>
Subject: [TCML] Tuning a coil PLEASE HELP
To: tesla@xxxxxxxxxx
Date: Tuesday, May 5, 2009, 9:48 PM

So I've asked for tuning help before and one or two people responded with a
link which was somewhat helpful... but now I need to refine some questions

What im asking from the list now is two things, one question and a confirmation
on setup...

First, the general question which applies to all tuning setups. The link I was
sent to learn to tune the coil can be found here:
In this explanation (and any other explanation out there) after you setup
everything you are supposed to turn up the frequency on the signal generator
until the amplitude on the scope reaches a max. At this max is your resonate
frequency. Um........ I'm no electrical engineer but when you change the
frequency shouldn't the sine wave get longer and shorter (Freq modulation)
not get higher (amplitude modulation)????? What am I doing wrong because when I
setup the test and do exactly what they say to do I dont get their results
(amplitude modulation) I get frequency modulation as expected....... PLEASE HELP

See these links to my server for diagrams of my setup. What I really need is an
explanation of physical setup, not schematic.

Secondary self resonance: http://host.atomiklan.com/tesla/scope1.PNG

   In this first setup the signal generator has two ports. A 20v and 5v. Which
should I use? Also each ports probe has red and black alligator clips. Red goes
to base of secondary and black goes where? Is this     diagram correct?

Primary self resonance: http://host.atomiklan.com/tesla/scope2.PNG

   In this diagram I just think everything is wrong. Can someone please correct
my diagrams. Thanks
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