I have two suggestions:
1 - If the system is a standard engine alternator/regulator set up charging
your battery and supplying 12 VDC to all of your electrical components, you
can try adding a 20,000 uF Capacitor ( rating of min. 25 volts). This will
act as a "filter" for some forms of electical noise.

2 - If the source of the the noise is related to your high tension ignition
( distributor/spark plugs) and shielding the spark plug wires is not an
option you can purchase a special "ignition noise" filter from most
automotive parts distributors.

If the kill switch you mentioned is similar to a magneto on/a/b switch such
is on a power aircraft, the wiring for this switch should be shielded and
ensure that the shield is connected to your aircraft ground.

I hope this info helps you.

James Swank
"Per" wrote in message
...
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