On Thu, 16 Mar 2017 08:19:39 -0000 (UTC), gregz
wrote:

Jeff Liebermann wrote:
I use RG-58c/u for 50 ohm test leads. The stranded center wire is
more flexible than the rather stiff RG-58a/u.

A/U is stranded center too. Rg58 is solid. Au cu difference seems to be
outer covering difference.
Greg

Oops, you're right. I stand corrected:

RG-58a/u (Belden 8259)
http://www.belden.com/techdatas/metric/8259.pdf
PVC jacket
UL temp temp rating = 75C
Attenuation at 1GHz = 70.5dB

RG-58c/u (Belden 8262)
http://www.belden.com/techdatas/metric/8262.pdf
Non-contaminating PVC jacket
UL temp temp rating = 85C
Attenuation at 1GHz = 74.8dB

So, different jackets, higher temperature rating, and less loss for
RG-58c/u. Also, RG-58c/u appears to have a military designation
(MIL-C-17, M17/155-00001), while RG-58a/u does not.

Mo
https://abrind.com/faq/
Q: I see different jackets types advertised, what are
the differences, and why I should care?

A:Jacket Types:
PVC-I Polyvinyl Chloride (PVC), black (contaminating).
Contaminating jackets will breakdown from sunlight (Ultra-Violet
Resistant), and cannot be buried. The PVC-I is rated with a
shorter life cycle than PVC-IIA. Suitable for low grade jumpers.

PVC-IIA Polyvinyl Chloride (PVC), black (non-contaminating).
Non-Contaminating jackets will not breakdown from sunlight
(Ultra-Violet Resistant), and suitable for direct burial
without conduit. The PVC-IIA is rated with a twenty-year
life cycle. The best all-around jacket.
(etc...)

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558