[volt-nuts] Best way to measure micro Ohms

[Charles Steinmetz]

David wrote:

> Thanks.  You have confirmed what I was thinking - it is *probably* the
> oxide causing the problem.
>
> It's not a waveguide in the normal sense of the word, transmitting a TE or
> TM wave down a hollow tube,  but more like a coaxial line transmitting
> something close(ish) to a TEM wave. The outer conductor is uncoated
> aluminum and rectangular in cross section.  The inner conductor is brass.
> See pictures attached

Looking at the pix, there appear to be lots of aluminum joints due to 
the "built-up" construction, maximizing the potential for the sort of 
troubles you are having.  I would re-make the piece in brass, doing 
everything possible to use as few pieces as possible (for example, by 
milling recesses into one piece rather than building up a compound piece 
from more easily machined sub-parts).

I would also plate everything in silver.

Best regards,

Charles