On 2 Jan 2005 10:22:21 -0800, wrote in
. com:

I've got a Mazda Tribute (near replica of the Ford Escape) and have the
dreaded RFI from the electric fuel pump. I've done a ton of research
on the Internet and determined that the most popular option for
resolving the issue is to install a RFI filter on the pump. This
involves dropping the tank, which is beyond my capability. So, to do
the install will involve a trip to the dealership, costing around $200
for parts/installation.

I've also seen a homebrew ferrite filter that can be installed at the
power lead for the fuel pump, which is an option.

But, I did see one posting where a guy resolved the problem by
upgrading to a K40 antenna, which he said filtered the RFI. So, I'm
wondering if anyone has had success eliminating fuel pump RFI with a
good antenna? I'm willing to give that a try, but it will probably
involve ordering one, so if there's only a small chance it will work
I'll probably skip this option and go straight for the filter.
Thoughts?


Three questions, if you don't mind:

1. How is your radio mounted and grounded?

2. Are you using power from the lighter socket?

3. What kind of antenna you you have now?

1. It's mounted using a standard RS bracket within a plastic
compartment on the console.

2. No, powered from the fusebox.
3. Grounded to a bolt on the door hinge.

On 2 Jan 2005 11:15:17 -0800, wrote in
.com:

1. It's mounted using a standard RS bracket within a plastic
compartment on the console.

snip

3. Grounded to a bolt on the door hinge.


Seems you have a floating (ungrounded) system. DC ground is not the
same as RF ground, the latter needing as short a wire as possible. In
fact, the antenna base should be mounted directly to some bodywork and
you can't cheat by running a wire to a ground somewhere else. The same
should be done with the radio if possible, although a -very- short
wire from the radio to ground (the deck beneath the console) should be
OK as long as your antenna mount is well grounded.

The reason RF grounding is so important is because a floating system
picks up noise very easily. Also, the antenna works much better when
properly installed. You can gain 2-3 S-units (and increase your
transmit range proportionately) by properly mounting the antenna. I've
installed lots of CB and commercial radios and as long as everything
is grounded (RF ground) there is rarely a problem with RFI..... unless
the alternator is going bad or something like that, but you would be
able to hear that in your AM/FM radio, too.

It's either that or drop the tank.