Re: Shorted loops of concrete reinforcing effect res freq?

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

Original poster: "Barton B. Anderson by way of Terry Fritz <teslalist-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi Christopher,

Moving the coil outside changed Fres. The amount of change depends on how 
much the walls, ceiling, and misc. objects Cext were affecting the coil. 
Moving outside typically frees the coil from most of these objects. It's 
possible the change moved Fres right where you want to be or very near. I 
wouldn't expect the steel reinforcement under the concrete to play a large 
role as it's typically at ground level, but then, I'm not exactly sure of 
your environment. I would expect Fres is the most likely cause. Retuning is 
not always necessary unless the change to Fres is enough to move it out of 
resonance. A little height adjustment of the toroid is an easy method to 
fine tune the coil.

Take care,
Bart


Tesla list wrote:

>Original poster: "Christopher Rutherford by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <Christopher.Rutherford-at-comindico-dot-com.au>
>
>Hello,
>I recently move my coil outside of my garage to run it and have found its 
>working much better. I suspect that the loops in the steel reinforcing 
>under the concrete of may garage may have loaded it??
>I don't think I should have to retune it now that its had these 'shorted 
>turns' removed, is this right?
>Basically only the Q has gone up? ...is this thinking right?
>Cheers & thanks
>Chris
>
>