Sustainer engine ignition noise (Solo2350)

Having a Solo 2350 on a Ventus 2cT, I've been annoyed that when it runs it
constantly triggers the squelsh of the VHF-radio. (No, raising the trigger
level doesn't do the trick)
It is possible to use the radio with the squelsh turned off and using a
headset. This makes the noiselevel even higher, than running with the engine
itself, which is too loud to begin with.

Doing the five year maintenance service, I finally took a look at the
wiring, now it was disassembled anyway. It turns out that none of the
ignition wiring is shielded, which obviously is the main contributer to the
problem. For instance, the wiring to the kill-switch on the instrument panel
runs parallel to all the other cables over a long distance.
It would be fairly easy to pull shields around all the cabling and it won't
be the weight of it that matters.

The Schempp-Hirth electrical diagrams shows no use of shielding. I've looked
to the newly released manuals for the DG-1000T which uses a similar
installation. The DG also uses no shielding.

My question now is, does someone have an explanation to why this is?
Could there be any good reason for not shielding the ignition wiring apart
from laziness?


/Per, Denmark