Mobile Line Noise

[loosecannon]

Pamm, i saw that your vehicle is a ford, and it reminded me of this article:
http://97vette.com/sporttrac/rfi_fix/rfi_fix.html

this should give you a place to start and also help you understand what needs to be done.
LC

 

[Pamm r]

Please let me know if it helps, Thanks

 

[sonoma]

it is going to take over a week to get it from the time ebay states it will get here. I know I will not be in any hurry to install it since the other items I have on the fuel pump is working for me. just bought one since I hardly see them for sale any more. A-1 electronics in Michigan use to sell them but I stopped doing radio repairs in 2012 so dropped my license and no longer buy from them. you have to have a tax number to buy from them.

 

[Sarasota Slim]

Looks like those "type 2 toroids", referenced in that article posted by LooseCannon, are pretty inexpensive.

Frys Electronics has them for just over a couple of bucks, a piece.

http://www.frys.com/product/2320969?source=google&gclid=CIzzzaHO7tMCFQeBswodDcQMvw

That signal sniffing trick was pretty spiffy, too.

 

[222DBFL]

It's either easy or very hard to kill engine noise. Every install is different and so are vehicles manufacturers use of different materials besides metal these days!!
Also I meant to tell you to also check all your ground connections under the hood if o didn't already or someone else didn't.
Remove any/all paint from connection point and apply a light coat of NO-OX. You can buy NO-OX special "A" grease from EBay. Here is a pic of what I am speaking of just in case you're unsure of what it is. Just type no-ox into search bar on eBay. Anyhow. Hope you get it all squared away. It's a lot of work at times, depends on well you want your radio system to be, if you want to be the best it can, then these things are needed to get there. Again, hope you get it resolved!!
Also the other parts you can get off eBay. Just google toroid choke, you'll find some that already have the wires wrapped onto them.
Hope some of my early morning brick wall text helps LOL!! Good day.

 

[Pamm r]

Looks like those "type 2 toroids", referenced in that article posted by LooseCannon, are pretty inexpensive.

Frys Electronics has them for just over a couple of bucks, a piece.

http://www.frys.com/product/2320969?source=google&gclid=CIzzzaHO7tMCFQeBswodDcQMvw

That signal sniffing trick was pretty spiffy, too.

Thanks I see that is a good price, So does the circle just go over the wire close to my fuel pump, just tie it there? Sorry for the dumb questions, just never seen one before

 

[222DBFL]

You really need some extra wire to do it right as you want to make as many wraps around the choke as possible. Then add it inline to the existing wiring for the part.

 

[Sarasota Slim]

Thanks I see that is a good price, So does the circle just go over the wire close to my fuel pump, just tie it there? Sorry for the dumb questions, just never seen one before

By all means, keep asking questions. That's how you learn. I've actually been quite impressed at your persistence, and willingness to try all suggestions, instead of just deciding that it's too hard, or too much of a nuisance, and giving up.

Like 222 said, above, the project will require some extra wire. It will also require multiple toroids.

Scroll back up to the article that LooseCannon posted (the website seems to be about a Corvette, but the specific article is actually about solving a problem like yours, on a Ford vehicle) The article contains instructions, as well as pictures, so you'll have an idea of what those toroid rings and extra wire should look like when you've assembled them, prior to wiring them in.

As the project would require splicing into the factory wiring system, you may wish to, if you haven't done so already, acquire a repair manual for your truck, with wiring diagrams, so that you can compare the instructions in the article to the appropriate wiring diagram, to make sure you're doing it right.

Here's a repair manual that you can purchase:

https://www.chiltondiymanuals.com/p..._medium=feed&gclid=CNOdkKio8NMCFdpLDQodjREK5A

As a side note, these manuals are good to have, as a general rule. If your vehicle is acting up, whether or not you feel inclined to fix it yourself, you can at least use it to research and troubleshoot the problem, so you have an idea of what's going on when you take it to the shop. And, if the mechanic tries to sell you unneeded services, you have a better chance of catching him in a scam.

There also appears to be manuals available as free downloads online, if you do a Google search, but I have never used them, and cannot speak to their accuracy. I'd be inclined to spend the $25 on a Chilton manual, were it I.

Also, O'Reillys Auto Parts (or AutoZone, or Advance) should have Haynes manuals for your truck. Haynes has wiring diagrams, too. I've used those manuals with some success, in the past, on a variety of vehicles. I think that Chilton and Haynes are the same company, anyway. I'm not sure what the difference between the two brands is.

At any rate, you may wish to print out the article, so you can make notes on it and have it right there when you are doing the project.

Also, be sure to waterproof your splices! Find some liquid electric tape to coat your splices; I picked some up from Walmart, the other day.

 

[loosecannon]

pamm,

This all has to do with the magnetic fields around any wire in which current is flowing.

in the most general terms, the job of the ferrite "bead", when slid over a wire carrying current, is to block the RF currents that are radiating from that wire and being picked up by your antenna.

so, if sliding a donut shaped piece of ferrite over a wire helps to block the RF current, then wrapping that same wire around the donut and passing the wire through it again will increase the "blocking power" by a significant amount.

when you look at is this way, it's easy to see why wrapping 5-10 turns of wire around the donut will be MUCH more effective than just passing the wire through once.

so if you're going to go to the trouble of interrupting a wire in order to put a ferrite donut over it, you might as well get as many turns of wire around it as you can, so you don't have to come back and do it again.

in the article i posted, you can see that the author tried just one "donut" and ended up using around five.

Looking back over the thread, i noticed a couple of things in your responses that we should clarify.

first, you cannot check for a good RF ground with a multimeter. just because the meter says "0 ohms" or beeps to indicate continuity does not mean you have a sufficient RF ground.
sure, you can measure DC ground with it, but RF is a different beast, and while a wire can look like a perfect path for DC current, that same wire can look like an insulator for RF current.

I see you did the antenna removal test and have determined that the noise is being picked up by the antenna and not running on the power wires, which means you don't have to add filtering to the power wires.
(However, just so you know, running your radio's ground wire right to the battery negative terminal does absolutely no good if your battery isn't connected to the body, the engine block, and the frame, with braided strap. you would be better off making sure this is done, and then you can just run a short ground wire from the radio to a convenient body grounding point under the dash.
you can look up "big three upgrade" on youtube and you will find a bunch of car stereo videos showing how to do this)

anyway, you need to do another test. you need to remove the center coax connection from your antenna, leaving the shield connected, and try the noise test again with the engine running.
this time, if there is noise with the coax connector hooked to the radio, but no noise when disconnected, you know that your coax itself is part of the problem and no amount of grounding at the antenna will fix your problem.
since your coax is running right near your fuel pumps, you need to make sure you are using high quality double shielded coaxial cable such as LMR-240UF or equivalent.

if you have cheap coax, then the shield may be allowing RF in.
you can try running a separate length of coax temporarily keeping it far from the fuel pumps in order to test this also.

you say you have a whip antenna mounted to the bumper of your truck.
what kind of whip? (if you already stated this, i missed it)

to have a good RF ground from the bumper itself to the frame, the mating surfaces must be ground down to bare metal before being bolted together.
just because your meter shows continuity means nothing.
the bumper is not a great place to mount an antenna because much of the antenna's length is running right next to the metal body of the vehicle and will change your antenna's radiation pattern.

your best bet is to mount an antenna on top of the cab, but obviously this is not an option for everyone.

i hope i have given you some insight into what is going on and some ideas on how to proceed from here.
LC

 

[Pamm r]

Thanks for the reply. To answer the few questions, it's 102" S.S. Whip. I used new rg8x coax 18' long with 4 point hand soldered pl259's. My coax is attached between the frame and the fuel pumps so it my help to move to the outside of the frame so the frame blocks the coax? I think all my grounds test great , it's the pumps because I have two tanks with a pump in each and I have noticed the when selected one pump emit more noise than the other. And by doing the turn key on and hear the pump build pressure for 1 sec. had the noise until pump stops.

 

[loosecannon]

well it sounds to me like a bunch of ferrite is in your future.

here is a kit that might help: http://www.ebay.com/itm/stardrift-1...299064?hash=item237f578b38:g:TTQAAOSwTuJYu2dt

my recommendation would be to buy a roll of stranded copper DC power cord like this:
http://www.ebay.com/itm/25ft-16GA-G...505499?hash=item1c6240e95b:g:rVAAAOSw2gxYt9gw

and to wrap a couple of turns through five of the beads all in a row and then put crimp on connectors on either end.
make up two of these assemblies.

then go under the truck, find the power wires going to the fuel pumps (power and ground) and cut them as close to the fuel pumps as is feasible.

then crimp on mating connectors, slide some heat shrink tubing over the wires for water protection, and crimp in your new filters.

there is another option also.
check out this mount: http://www.ebay.com/itm/FireStik-SS...844476?hash=item41b83c767c:g:Gn4AAOSwXeJYG6VN

if you chose to use this mount, your antenna would be higher up on the vehicle, your coax could run through the bed instead of under the truck, and you would have the shielding of the bed itself between the antenna and the fuel pumps.

best of luck, and just as a tip for every mobile operator out there, a set of these placed right at the feedpoint of your antenna will improve your performance and really clean up common mode issues: http://www.ebay.com/itm/Snap-On-1-1...497277?hash=item20f9d5e1fd:g:RqAAAOSwrklVVVyV

honestly it's one of the best improvements you can make to your mobile system IMO.
LC

 

[Pamm r]

Well first of all thanks for all the help from this site. I put a choke on close to the fuel pump and I raised my whip from the left bumper to the upper part of the grounded tool box. It fixed all my line noise from my fuel pumps.

 

[rabbiporkchop]

Thanks for the reply. To answer the few questions, it's 102" S.S. Whip. I used new rg8x coax 18' long with 4 point hand soldered pl259's. My coax is attached between the frame and the fuel pumps so it my help to move to the outside of the frame so the frame blocks the coax? I think all my grounds test great , it's the pumps because I have two tanks with a pump in each and I have noticed the when selected one pump emit more noise than the other. And by doing the turn key on and hear the pump build pressure for 1 sec. had the noise until pump stops.

You can improve the signal to noise ratio by using better coaxial cable also for better receive. I've seen 1db of loss in just a couple feet of similar cable.

 

[loosecannon]

glad to hear it Pamm.

now it's time to get on the air and get all the boys cryin' over you!
LC

 

[Slowmover]

well it sounds to me like a bunch of ferrite is in your future.

here is a kit that might help: http://www.ebay.com/itm/stardrift-1...299064?hash=item237f578b38:g:TTQAAOSwTuJYu2dt

my recommendation would be to buy a roll of stranded copper DC power cord like this:
http://www.ebay.com/itm/25ft-16GA-G...505499?hash=item1c6240e95b:g:rVAAAOSw2gxYt9gw

and to wrap a couple of turns through five of the beads all in a row and then put crimp on connectors on either end.
make up two of these assemblies.

then go under the truck, find the power wires going to the fuel pumps (power and ground) and cut them as close to the fuel pumps as is feasible.

then crimp on mating connectors, slide some heat shrink tubing over the wires for water protection, and crimp in your new filters.

there is another option also.
check out this mount: http://www.ebay.com/itm/FireStik-SS...844476?hash=item41b83c767c:g:Gn4AAOSwXeJYG6VN

if you chose to use this mount, your antenna would be higher up on the vehicle, your coax could run through the bed instead of under the truck, and you would have the shielding of the bed itself between the antenna and the fuel pumps.

best of luck, and just as a tip for every mobile operator out there, a set of these placed right at the feedpoint of your antenna will improve your performance and really clean up common mode issues: http://www.ebay.com/itm/Snap-On-1-1...497277?hash=item20f9d5e1fd:g:RqAAAOSwrklVVVyV

honestly it's one of the best improvements you can make to your mobile system IMO.
LC

Nice explanation. Thanks!

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