Quote:
Originally Posted by G8HQP Dave
Not true. A coax cable has inductance but near zero pickup ...
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I can confirm this. In a previous life I looked after a large pulsed power source which accelerated an electron beam to drive a gas laser. When the switching was well synchronised the electrical part of the machine could raise the e-beam current from zero to 600kA in about 15ns. That's quite a dI/dt and also quite an effective source of pulsed RF.
We screened it as well as we could, but the laser light had to get out somehow, and the beams were approaching 40cm in diameter. So the wiring for our diagnostics had to be, um, insensitive to RF pickup. We could get away with good quality braided-outer co-ax over short runs relatively far from the machine. But cables which had to go any distance or run anywhere near the loud end of things had to be solid-outer. We liked Heliax a lot
http://www.commscope.com/catalog/cab...s.aspx?id=1342. I've yet to see any used for audio. But maybe it's just a matter of time ...
Cheers,
GJ