TSSP: List Archives

From: "Malcolm Watts"
Date: Tue, 24 Oct 2000 19:02:55 +1300
Subject: Re: [TSSP] The Q answer!?

I wasn't going to say anything before having sent a post about 
this (in addition to others I sent to the builder's list in 
the past), but........

On 23 Oct 00, at 19:00, Terrell W. Fritz wrote:

> Hi All,
> 
> I have figured out the Q problem.  It's the Sonotube...
> 
> I simply placed three bare coil forms (no wire) into the center of my
> big secondary and measured the resulting Q.  Picture at:
> 
> http://63.225.104.49/TeslaCoils/Misc/PaulNich/SonoQ.jpg
> 
> The bare coil has a Fo of 146.6kHz and a Q of 73.3
> 
> The first 21 x 6 x 1/4 inch plastic tube gave an Fo of 164.43 and a Q
> of 66.5
> 
> The second 48 x 7.125 x 0.125 Sonotube gave an Fo of 144.79 and a Q of
> 32.25!!  Yes, that really is 1/2 !
> 
> The last 27 x 4.125 x 0.125 PVC tube gave an Fo of 146.6 and a Q of
> 68.82.
> 
> I have no idea what is in the Sonotube but paper and
> wax/glue/plastic... but it is definitely high loss!!

I knew it, I knew it, I knew it!  I actually threw a coil away 
once because its terrible Q (about 40) almost prevented it 
from sparking.

Regards,
Malcolm


Maintainer Paul Nicholson, paul@abelian.demon.co.uk.