Re: Coil data & wall distances

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

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

Hi Weazle,

Thank you for this information. (more intersperced).

Tesla list wrote:

>Original poster: "J. B. Weazle McCreath by way of Terry Fritz 
><twftesla-at-qwest-dot-net>" <weazle-at-hurontel.on.ca>
>Here are the measurements from the centerline of the secondary to
>the four walls.
>
>Wall one is 6.5 feet and is standard studs with wood sheeting.
>Wall two is 10 feet and is mostly an 8 ft. x 9 ft. metal door.
>Wall three is 9.5 feet and is a metal rack holding firewood.
>Wall four is 10 feet and is standard studs and wood sheeting.
>
>The PDT is the largest metal object near the coil and it sits right
>by the metal door (wall two), so possibly it can be concidered as
>being part of the door, seeing as they're both metal.

I wouldn't consider the PDT as a wall distance. No doubt there is an 
external capacitive coupling between the coil and PDT, but still, in this 
case I would just use the wall distance behind the PDT. Looks like the 
average wall distance is 108 inches. With my coil, I found that the average 
wall distance matched very closely my actual measurements. What I've found 
with ET6 and my coil measurements was that the nearest wall distance was 
needed. I believe I included the same instructions in fantc and will need 
to update that. It would be good to get more data just like your from other 
coils out there. What is really needed here with your coil are actual 
measurements (the least being Fres of the coil using a signal generator and 
dangling a small wire from the scope probe about 2 coil lengths distance 
form the coil to minimize scope loading).

>Four feet directly above the toploads is a grounded strike plate to
>protect the garage door opener.  Oddly, I've only had one strike to
>it, as the streamers generally are horizontal, but it left quite a
>burn mark!

That's interesting. If 48 inches above topload, then that should make this 
object 112 inches or so above the ground plane. Previously, the ceiling 
height was stated at 100 inches, so we have a discrepancy there. Actually, 
this object should be modeled as an object above the coil (ground 
connection). A disc would model it best just giving it a 0 ID and inputing 
the height and OD (approx. if square plate). The ceiling height will end up 
being above this value.

It sure would be great to get a real Fres measurement if you have the time 
and the gizmo's. Do you have any misc. measurements on this coil like 
inductance, capacitance, etc.., or are these calc'd values?

Anyway, thanks again.
Take care,
Bart