The Ford doesn't use independent iginiters...it is a six with old fashioned
spark plugs and wires... I wish it weren't so because I believe suppressing
RF on the primary would be a much easier task.
----- Original Message -----
From: <dgsvetan@rockwellcollins.com>
To: "WA3GIN" <wa3gin@comcast.net>
Cc: "Peter Laws" <plaws0@gmail.com>; <rfi@contesting.com>
Sent: Monday, January 11, 2010 6:18 PM
Subject: Re: [RFI] Ferrite Beads from DX Engineering
> Dave,
>
> I would say that the recommendation given to you was, in fact, a pretty
> good starting point. After all, when you consider the nature of the
> ignition system waveform, and the fact that in many vehicles today, each
> plug is fired by its own dedicated high voltage circuit (no more
> distributors), putting at least one bead on each spark plug lead is a
> reasonable first step. If you only do a few, you are likely to get little
> or no useful results. Of course, if you can determine that SOME
> particular wires are more troublesome than others, by all means, treat
> only those and see what happens.
>
> Be advised that for some vehicles, full RFI suppression can make the DXE
> proposal look like a bargain basement sale. A fellow aerospace engineer
> in CA had some real problems with his import SUV or pickup (I don't recall
> make/model) several years ago. He did submit an article on his cure to
> QST, but I am not sure it was published. I did see the submitted master
> article, with photographs, and in this instance, full suppression to make
> an Icom 706 useable in the vehicle required FULLY shielded ignition wires,
> a fully metal-plated distributor cap (for terminating the ignition wire
> shields), and special fittings for connecting the wire shields at the
> cylinder head end. (Without terminating the shield at both ends to the
> engine chassis, the shields were ineffective.) He also added lots of
> bonding braids between various parts of the vehicle, as well as bonding
> the exhaust pipe to chassis so that it was no longer a radiating antenna.
>
> Good luck. Many successful vehicular RFI solutions do take a lot of time,
> patience, engineering thought, and yes, cash.
>
> 73, Dale
> WA9ENA
>
>
>
>
>
> "WA3GIN" <wa3gin@comcast.net>
> Sent by: rfi-bounces@contesting.com
> 01/11/2010 04:53 PM
>
> To
> "Peter Laws" <plaws0@gmail.com>, <rfi@contesting.com>
> cc
>
> Subject
> Re: [RFI] Ferrite Beads from DX Engineering
>
>
>
>
>
>
> Peter,
>
> I asked the DX Engineering fella how best to approach the RFI and he said,
>
> start with one clamp on per spark wire, then just add more in series till
> the noise is reduced. That doesn't like an inexpensive solution to me and
> I
> don't think it will work either, haha.
>
> If I win the lotto I'll buy new spark wires and install 15 beads each and
> report the results ;-)
>
> 73,
> dave
> wa3gin
> ----- Original Message -----
> From: "Peter Laws" <plaws0@gmail.com>
> To: <rfi@contesting.com>
> Sent: Monday, January 11, 2010 5:45 PM
> Subject: Re: [RFI] Ferrite Beads from DX Engineering
>
>
> On Mon, Jan 11, 2010 at 15:23, Jim Brown <jim@audiosystemsgroup.com>
> wrote:
>
>> Ferrite beads in pulsed circuits (like spark plug wires) would work
>> slightly differently. There, they work by slowing down the rise/fall
>> time of the current pulse (or smoothing its corners), which in turn
>> reduces the strength of harmonics. It's those harmonics that we hear
>
> Really?
>
> Well, I mean not "really" as in "you don't know what you're talking
> about" but as in "wow, the SAE types spend a lot of time getting those
> rise-fall times just right so that the car meets the applicable
> standards for fuel consumption and emissions" ... Although not
> mandated, there are also drivability concerns as well ...
>
> Just how much would chokes change that? And how does this compare to
> the old "resistor plugs" that were sold to make the ticking on the car
> radio go away?
>
>
>
>
> --
> Peter Laws | N5UWY | plaws plaws net | Travel by Train!
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