Primary AC resistance measurements, Part 3

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-hp-dot-com>

For those following the primary inductor AC resistance measurements that I
began 1-2 months ago, I have a new installment on my web site.  See
http://www.laushaus-dot-com/tesla/primary_resistance.htm

I discovered that my marginally-performing Litz wire was in fact comprised
of #30 strands, not #38 as I was led to believe.  Since higher frequencies
require finer stranding, I think this accounts for what was measured.

I re-measured the #10 stranded coil and found that the test leads I had
used for just that coil added significantly to the resistance.  The new
data still shows that stranded wire is a poor choice.

Part 2 data showed that a two-layer copper tubing primary had a much higher
resistance than a single-layer version,  But it wasn't clear if this was an
artifact of the two-layer construction, or the fact that there were four
unused turns on each of the two layers.   I built a #14 solid wire
two-layer coil, but with no unused turns, to compare against the 1-layer
#14 coil.  The results of this were not at all definitive.  For the 1/4"
tubing, the 1-layer coil had the lower resistance (over all frequencies),
while with the #14, the 2-layer coil had the lower resistance (until
somewhere above 400 KHz). Not sure what to conclude...

Regards, Gary Lau
MA, USA