Re: CT100 Satellite Cable as interconnect

Cable Asylum

Interconnects, speaker wire, power cords. Ask the Cable Guys.

In Reply to: CT100 Satellite Cable as interconnect posted by Dave Billinge on July 26, 2006 at 06:16:16:

1st, it is not as rosy a picture as you paint. Lets be clear, that just like an RG number, the CT100 designation is NOT totally specific, there are materials variations within that designation, which I will outline below.
2nd, CT100 is not as readily avialable in the US as it is in Europe, here you have to buy an entire spool of 500 feet or more. This limits the ability of folks to experiment with it.
The center conductor is nominally an 18 ga. bare copper conductor, but in all the samples I have seen here in the US, it was quite badly corroded, with a layer of dark, mostly black over the surface. Removing the insulation did not remove any of this tarnish. AAdditionally, 18 ga. is on the large side for a center conductor, starting to invoke some transient smearing and lack of focus compared to smaller diameter wires.
The insulation is not really an air dielectric, there is significant amounts of PE (polyethylene) next to and surrounding the center wire. In fact, a geometrical analysis shows that there is probably as much, OR MORE, plastic material near and surrounding the center wire, as there is for a foamed dielectric core, despite the large air channels in the middle area of the CT100 dielectric.
The exact pattern and amount of plastic varies from brand to brand, so they are all not the same in this respect.
Aside from how much total amount of air is actually present, the PE is just not as good of a dielectic as one of the teflons.
The shield is a combo shield, that is, it has a foil layer and a braided layer. Unfortunately, due to variations between brands, this can be a mylar with copper layer, and then the copper braid, OR it can be a thin but pure copper foil and then copper braid, etc. The amount of coverage of the braid can vary, as can the exact sealing mechanism of the foil seam.
Folks have reported problems with the "pure" copper foil variant having the foil fall apart due to friction with the braid wires, which leaves a lot of intermittent contact issues occuring.
For analog line level audio use, I have found that two different layers of materials for the shield on a coax sounds worse than a single layer of material. I conjecture that there is some amount of signal 'crossover' between the two layers (most people do not realize that the so-called shield actually carries the audio signal every bit as much as the center wire does, and is critical in the overall sound quality).
I have made measurements that confirm as the frequency rises within the audio band, more and more of the signal is carried by the outer layer of the shield compared to the inner layer.
So while the CT100 seems to have a lot going for it, in fact, it has some issues that are not optimal for high performance audio use.
For more on audio cables, see:
http://www.geocities.com/jonrisch/cables.htm
and more specifically:
http://www.geocities.com/jonrisch/i1.htm
and subsequent pages.

Jon Risch

This post is made possible by the generous support of people like you and our sponsors:

VH Audio

Follow Ups Full Thread

Topic - CT100 Satellite Cable as interconnect - Dave Billinge 06:16:16 07/26/06 (4)

Re: CT100 Satellite Cable as interconnect - Jon Risch 21:09:21 07/27/06 (1)

Thanks Jon - Dave Billinge 01:18:24 07/28/06 (0)

Re: CT100 Satellite Cable as interconnect - zanash 23:38:36 07/26/06 (1)

CT100 Satellite Cable as interconnect - Dave Billinge 10:46:17 07/27/06 (0)

Follow Ups

Re: CT100 Satellite Cable as interconnect - Jon Risch 21:09:21 07/27/06 (1)

Thanks Jon - Dave Billinge 01:18:24 07/28/06 (0)

You can not post to an archived thread.