I've had similar problems, mostly with a cellular phone - not a CB. The
observation of solid copper wires being a problem is definitely a
contributing factor is correct. I already have negative ground in the TD,
but have had the best luck changing to silicon core resistance plug wires.
The only down side of this is that the somewhat lower voltage to the plugs
has caused a bit more fouling than normal. This can be mostly overcome with
a higher output coil - like the Lucas Sport coil.
Also correct is the use of capacitors and any other spark suppressors.
Don't overlook a similar capacitor across the generator output. The
commutator brushes are another major source of interference.
32, 50, 59, 72 MGs