| Author |
Message |
    
Capt205
Member
Username: Capt205
Post Number: 91
Registered: 5-2005
| | Posted on Friday, May 12, 2006 - 11:34 am: | 
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I have a 2003 Ford F-350 with the PowerStroke Diesel. Radio is the Magnum S9 and the antenna is a Wilson 5000 drilled in on the roof center.
I still have noise getting in, and when I disconnect the antenna at the back of the radio, it goes away, 100%. I did some work last week and cleaned up what was getting in on the power leads, but what can I do about noise getting in on the antenna lead? I seems to be related to the alternator as it rises and falls with rpm's
There is also a popping type noise that sounds like spark plugs when on sideband, but this is a diesel. Could it still be alt noise or maybe injector noise? Where do I start? |
Tech237
Moderator
Username: Tech237
Post Number: 341
Registered: 4-2004
| | Posted on Friday, May 12, 2006 - 4:56 pm: |
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OK. Try getting a round ferrite toroid and as close to the antenna wind half of the toroid with the coax going clockwise and then the other half with the coax wound anti-clockwise.
I suspect that this may help you to some extent. |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1223
Registered: 6-2004
| | Posted on Saturday, May 13, 2006 - 11:27 am: |
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The first thing you should try is bonding your engine hood to the frame at the hinges with grounding straps. Often this will solve the problem by acting as a shield to reduce the amount of noise emitted from your engine. If it doesn't, then you'll need to address the noise at it's source.
I've had excellent success with bypass capacitors and feed through filter capacitors, but there are noise filters/supressors sold that might be easier to use and more appropriate for your vehicle if it's still under warranty.
Why would ferrite stop received noise? The antenna is receiving the noise. Reducing the amount of RF traveling on the outside of the coax shield won't make a dent in the problem. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1573
Registered: 9-2004
| | Posted on Sunday, May 14, 2006 - 1:09 am: |
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hollowpoint's suggestions are good ones.
if you dont already run a noise filter, get one, they work pretty good.
i know that the noise is coming in from the antenna, but it couldnt hurt.
to cure your noise, you need to filter at the source.
get a couple of feed thru capacitors, and put one inline with the alternator hot lead.
the popping noise might be reduced by better plug wires. the noise suppression kind.
again, bonding is very important.
matt |
Capt205
Member
Username: Capt205
Post Number: 94
Registered: 5-2005
| | Posted on Sunday, May 14, 2006 - 11:49 am: |
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This is a diesel, no plugs. I have a noise filter on the power wires for the radio. I have placed some of the clamp on ferrite's on the power leads at the radio.
The truck is well grounded with tinned braided copper grounds at all 4 corners of the cab to frame, all 4 corners of pickup box to frame, both batteries to front fenders, and the hood on both hinge corners is also grounded, hood to firewall.
Radio has a ground to the seat bolt, amp is grounded to the rear seatbolt. I just switched the jumper to rg213 between radio and amp, that seemed to help alot. Still not 100% gone though. |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1435
Registered: 7-2004
| | Posted on Sunday, May 14, 2006 - 3:17 pm: |
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I justed resolved some issues i had with noise
in my Mazda car. I made sure radio and equipment was grounded good using 1 inch copper braided strap. I grounded engine block to frame using
1" copper braid strap. I grounded 12 inches
in from the end of my tailpipe with strap to
frame. Grounded muffler to frame with strap.
Grounded doors and hood. I bought new double shielded coax. Placed ferrite cores on the
coax right after the antenna and where it comes out of radio and equipment. Replaced my radio power wire with Twisted pair wire that run to battery. Also have ferrites wrapped on this wire.
Placed a alternator filter on the alternator. Wrapped cooling fan wire around a ferrite.
Replaced regular spark plug wires with resistor
wires and resistor plugs.
Luckily i had all the ferrites, straps, ect
which i have been buying over the past year.
And finally just about 4 days ago i placed everything on the car and it took 99.9% of the noise out. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1583
Registered: 9-2004
| | Posted on Sunday, May 14, 2006 - 6:24 pm: |
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yep, you've got to filter the noise at the source at this point.
i would say alternator because of the noise you describe and also because they are just nototious for this.
feedthrough caps can be found at RF parts, or some auto parts stores.
if you cant find one, try a 4700uF 50volt cap on the hot lead of the alternator to ground.
pos. end of cap to wire of course.
also, try putting the snap on ferrite over the alternator's power leads.
ALWAYS best to try to filter noise at its source.
matt
BTW, nice install!!! |
