On 11/10/2015 10:10 AM, amdx wrote:
On 11/10/2015 2:02 AM, rickman wrote:
On 11/9/2015 7:52 PM, Jeff Liebermann wrote:


My solution would be to use aluminum instead. Copper is not really
superior in a meaningful way and costs a lot more.


Money rears it's head as an issue, aluminum is cheaper.
+1 for aluminum.
Resistivity is 65% higher for aluminum.
I'd give that a -1, however, if maximizing Q is not
important in your design then still at +1.

I can overcompensate for the increased resistivity by using larger
tubing and still save $$$, +1 for aluminum. Resistivity is not resistance.


Oxidation: Copper oxide vs Aluminum oxide.
Aluminum oxide is an insulator. How does that affect
skin resistance? I don't know, does it just shrink your tubing by the
thickness of the oxide?

How many atoms is that in aluminum? So we are talking nanometers? I
started with a tube that is 100% larger, so still lower conductivity.


Copper oxide is said to be a semiconductor, has much, much lower
resistance than aluminum oxide.
Page 5, http://www.ets-lindgren.com/pdf/emctd_1293_weibler.pdf

Or just varnish it.
Bottom of page, http://hamwaves.com/coils/en/


Aluminum is a great material to work with.

The oxides are irrelevant.

--

Rick