Teslalabor wrote: "it is completely useless"
No no, I wouldn't that!
True the streamers have a capacitance of a couple of pf / foot to upset
things, but the scope method gives a very good estimate and the smaller the
coil the more accurate it should be - less output, less effect.
You simply use the 'wire' method mentioned and then compare the difference
with and without the wire. I tune the primary around 8% lower, (82 down to
74 KHz approx)
Only trouble with the scope method is that you get harmonics show up as
well, so doing a sweep involves looking for the highest amongst the several
peaks that will occur. Using JavaTC beforehand will tell you the figure
reasonably accurately as a guide though, to avoid mistaking a harmonic as
the correct peak.
Phil
-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of Teslalabor
Sent: 04 April 2014 12:51
To: Tesla Coil Mailing List
Subject: Re: [TCML] Secondary Resonant Frequency test ??
I'm sorry but this method is nice in theory, but has nearly nothing to do
with reality and if done as described, it is completely useless because it
doesn't give you the real frequency under load conditions.
In reality a conductive streamer or arc is "nailed" at the topload, which
acts as a form of antenna and lowers the resonant frequency of the secondary
extremely.
So if you do this test you have at least to connect a thin wire to the
topload, which "simulates" a streamer, when the coil is running later.
----- Original Message -----
From: "Bart B. Anderson" <gort@xxxxxxxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Friday, April 04, 2014 3:55 AM
Subject: Re: [TCML] Secondary Resonant Frequency test ??
> Very easy...
>
> 1) disconnect the bottom wire to your secondary and connect the generator
> output to it (square wave is fine)...
> 2) power up the scope and let a piece of wire (12" or so) dangle from the
> probe and place the probe about toroid level and about 6 feet from coil.
> 3) sweep the generator increasing frequency while keeping an eye on the
> scope...
>
> When your scope shows a sine wave with the largest peak, that is your
> fundamental frequency.
>
> That's is the most basic.
>
> Take care,
> Bart
>
>
> On 4/3/2014 4:32 AM, matty mcqueeney wrote:
>> does anybody know any ways I could test the resonant frequency for the
>> secondary using a generator and a scope? I have already done the primary
>> and got the correct results.
>> Matthew _______________________________________________
>> Tesla mailing list
>> Tesla@xxxxxxxxxx
>> http://www.pupman.com/mailman/listinfo/tesla
>
> _______________________________________________
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