On Sun, 29 Apr 2007 15:36:43 -0500, "amdx" wrote:

This is then a characteristic of the Capacitor called D (dissipation).
Any increase in current tied to loss immediately goes to the bottom
line of resistance - it is a square law relationship, after all.

So your saying yes, the thought experiment would show more loss,
but the loss is in the capacitor. The loss in a capacitor would be
dielectric
and loss in the plates right?

Hi Mike,

Depending upon construction, most assuredly. However, little loss is
found in dielectrics (unless you are using particularly crummy
examples). For bad dielectric, you can expects arcs and sparks
followed by carbon, and then catastrophic heat accumulation. Most
lost is in what is specified in ESR (effective series resistance)
which you have already identified as in the plates, but often more in
the leads and their connections to the plates. To pack in more
capacitance, the trend is for thinner plates for a given package
volume. You can guess where the resistance will rise there when the
circulating currents are see-sawing in that thin metal.

(let's not get into radiation resistance right now)

Why not? Small loops suffer by comparison, and multi-turn loops even
more so.

I figure it would only confuse the issue.
I was trying to stay away from radiation resistance because my experience of
the effect Bill ask about has been with small aircore inductors. But on
second thought
even those have Rr.

The smaller, the worse. It is not so much about the size of Rr, but
its relation (ratio) to Ohmic loss. For instance, a 1 meter loop
composed of #40 wire is going to be deaf and dumb at 80M, but you
might have a chance with 10cM hollow pipe with tight connections. Both
exhibit the same Rr, but the wire's Ohmic loss is clearly deadly in
comparison to it, than for the pipe's Ohmic loss. Rr in this band,
for this size, runs on the order of 0.0075 Ohms.

Why does the reistance go up near resonance?

I haven't seen that happen. However, for the same resistance, as you
approach resonance, the circulating currents climb, and loss is by the
square.

73's
Richard Clark, KB7QHC