tubular braid

[daviethek]

always experimenting, especially when it doesn't cost anything.

An EE buddy at work gave me some left over Alpha tubular braided cable. It is multi strand (estimated 200) copper tubular braid at about 1/4 inch diameter and has what appears to be tin plating on each of the individual copper strands. ( it could be silver but the wire ID had a T/C designation so I figured it was tin over copper). Just for grins i put a few lengths of it into some 3/8 ID pvc tubing so there was esentially no insulation exept for air, cobbled up a couple of terminator pins and dropped them in the system. I was expecting crap but what I got was a darn fine sounding speaker cable not too far away in quality from my usual cable which for some reason I am always trying to replace which is Bedrock. Gave them a very hard listening and and it had all the good attributes like detail, and instrument separation. Finally they were just a micro tad more pronounced in the midrange so it was back to the bedrock but not without some soul searching. If anyone else has experimented with this type of cable or has braided cable in their system I would like to know if they had a strong preferene with this type of cable geometry over say solid wire. Adios, and still havin fun.

[jneutron]

1. Run one length of the braid OVER the tubing. At one end, twist the braid past the end of the tube, clamp it. Work the braid towards the free end, making it very tight over the tubing. Once done, fix the second end the same way as the first.

2. Take teflon tape, spiral wrap it over the braid, 50% overlap. This results in two layers of teflon. Repeat this, giving a total of four layers.

3. Put the second layer of braid over the teflon. Make it tight, like the first.

4. Use black tape, wrap the entire length. A little overlap is sufficient, this layer is only to keep compression on the structure.

5. Once complete, you can take the ends a part and fish out the two conductors.

What you have made is a coaxial cable, with extermely low inductance through the audio band, up to a Mhz. It will have a characteristic impedance close to 10 ohms, L will be about 10 nH per foot, C will be about 280 to 300 pf per foot. It will have minimal lagging energy storage.

It is very difficult to make a cable with better characteristics. Not impossible, but very very difficult..

If you try this, you of course must post your results.

Cheers, John

[daviethek]

Just got back from vacation and saw your post. Sounds like you have some experience with this type of cable. I'm going to follow your recipe since I have all the materials and actually.... why the hell not. Its nice to finally cobble up something myself that sounds lilke a worthwhile addition to my system . Your PTFE double wrap recipe may take it over the top. Thanks for your input and I'll report back when I get it done. Its no. 6 on my to-do list , my wife has the first five items. regards, dk.

[jneutron]

Its no. 6 on my to-do list , my wife has the first five items. regards, dk.

Wow, you have a short honeydo list..only 5 items?? You're almost home!!

Good luck

Cheers, John

[Resident Loser]

...wasn't that Mike Oldfield's music for "The Exorcist"?

jimHJJ(...and yes, it was a stupid irrelevant comment...)