Double-shielded mag wire?

Anybody know where I can find double-shielded wire? (I've tried the usual supply sources.) My radioman says my long (firewall to mag switch, 18 or 20GA, I think) single-shielded leads are causing my R/T noise. Thanks, Nick.

Note: These are not the "P" leads between the mags and the firewall, though it might be the same kind of wire.

WagAero and Chief Aircraft both have it. 18 gauge is ok for mags.

P Leads

I mount the mag. noise filters to the firewall and run 16 guage to them from the mag switch. I also run a 10 guage ground wire from the engine mount direct to the firewall. The engine has a grounding strap from the engine to the mount, but uses the engine mounting bolts to ground the mount to the fuselage. Over time the bolts will loosen and frett, the engine viberation will set up a harmonic in the engine to airframe ground which will cause radio and intercom noise. Crash

Thanks, fellows. T.J., I called both WagAero (Mary) and Chief; neither carries any double-shielded wire (not much demand, I guess).

S.F.
Nick

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