[Mobile-Portable] Radiated noise-Chrysler Town & Country van

[R Goodspeed (W7DGX)]

Pete and all,

I would hope the answers would be placed on the reflector. I have had ignition
and other mobile noise problems in the past and present. The last time I
successfully resolved everything was on a 1955 Plymouth. Since then,
improvements in noise blankers has made operation tolerable but not great.

I would love to hear all the possilbe methods so I can try them. I suspect each
vehicle is a little or a lot different. I have more time now to "play" and
hopefully get mine better.

        Rolly  W7DGX

"Peter E. Beedlow" wrote:

> To all,
>
> Looking for suggestions regarding quieting down the ignition noise in a 2002
> Chrysler Town & Country van. Here's the operating environment, what I have
> done and what I see as the problem
> :
> Vehicle information:
> Vehicle: 2002 Chrysler Town & Country eX
> Engine: 3.8 Liter V6
>
> Amateur equipment installed:
> Icom IC-706MIIG with the main unit installed under the rearmost passenger
> seat and the control head installed on the console between the driver and
> passenger seats. The radio is wired directly to the battery with a relay is
> installed in the positive lead to remove voltage 45 seconds after the
> ignition is turned off. The power leads for the radio were installed under
> the chassis of the van to minimize the change of any interaction with the
> installed van wiring harness. A heavy-duty noise filter, capacitors and
> toroid transformer, is installed at the radio position with a ground lead
> from the noise filter to the chassis of the vehicle.
>
> Antenna:
> Custom designed mount for a Hustler mast bolted to the tailgate of the van.
> Every effort was made to ensure good grounding from the vehicle to the
> antenna mount. No fluctuating SWR indications have been seen either during
> radio transmissions or during testing with an antenna analyzer.
>
> Problem and symptoms:
> Ignition noise is very apparent and loud enough that it makes operation of
> the installed amateur equipment almost impossible. The ignition noise is
> noticeable on the factory installed AM/FM radio in the vehicle, although
> typically a strong AM station will cover the ignition noise.
>
> Measures I have taken to reduce the ignition noise:
> --Spark plug wires and ignition system:
> The spark plug wires were covered with tinned, copper, braid and grounded to
> the engine. In addition the electronic distributor was covered with aluminum
> foil.
> -- Hood hinges:
> Both hood hinges were bonded to the vehicle body with tinned, copper, braid.
> -- Tailgate hinges:
> Both tailgate hinges were bonded to the vehicle body as recommended in TSB
> 08-23-99.
> -- Engine to chassis grounding:
> The factory grounding from the engine to the chassis is rather poorly done
> and I suspect will be a problem as the vehicle ages. I added a grounding
> strap from the passenger side engine mount to the chassis.
> -- Exhaust pipe:
> The exhaust pipe is grounded to the chassis in two places using muffler
> clamps and tinned, copper, braid.
>
> There is no noise apparent with the antenna removed from the vehicle (this
> is removing the antenna from the mount not removing the coax from the
> radio). This indicates to me that the problem is one of radiated noise. With
> the 706 noise blanker engaged I still see an S 3 to 5 noise level. With out
> the noise blanker it's S7 to 9. Unfortunately although this is acceptable
> (border-line!) for day-to-day operating on the county hunter's CW net, it is
> not acceptable for an mobile state QSO Party operations and that is one of
> my interests.
>
> I am working with the deal and directly with Chrysler but thought I'd ask
> "the experts" on this reflector and see if anyone has some ideas worth
> pursuing.
>
> Thanks and probably best to reply to me directly at nn9l@arrl.net.
>
> 73,
>
> Pete, NN9K
>
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