I have a pickup with a IC706MKIIG installed. The HF antenna is in the driver's
side middle stake pocket on the box. Moving the antenna does not help. The
noise is clearly audible on another radio in another vehicle.
It's a 2001 Toyota Tundra V8 (4.7 liter)--same engine as a Lexus. While there
is noise from two sources, the fuel pump I think I can figure out. What's
giving me fits are these new 100,000 mile no-maintenance engines. There is no
distributor. There are no plug wires. No coil. Only these spark plug pods.
Each of the 8 pods contains its own coil, condensor, and firing mechanism.
There are 4 light gauge, low voltage, wires going from each of these pods back
to the computer. None of the on-line or printed RFI resources I can locate
discuss this type of design.
The only 'serviceable' parts in the thing are the spark plugs. So I pulled the
pods off the engine block and replaced all 8 plugs. No change in noise. All
the traditional mitigation techniques have been tried regarding grounding all
the possible ground loops, of which I found none. The noise is clearly
centered on these pods.
I should say all techniques but one that is...
It appears that I'm going to have to completely seal that harness with a shield
of some sort. The trouble is, the harness is HUGE. It's the size of my wrist
and has wires going in and out all over. Does anybody know of a good way to
mitigate this type of noise, which is S9 on all bands <15M? Is the shielding
of the harness the way to go? What material does one use for this mitigation
technique?
On or off list would be fine.
Thanks
Ford-N0FP
ford@cmgate.com
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