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ZeDefender



Member Since: 15 Sep 2011
Location: Munich
Posts: 4731

Germany 2011 Defender 110 Puma 2.4 SW Baltic Blue
Interference reduction?
Hi guys
Earlier this year I fitted several USB sockets powered off the lighter circuit. Two are for a TomTom iPhone cradle and an iPad. They work great but when I play music into aux from the cradle, I get rpm-dependent noise at higher volumes. Do you reckon fitting one of these:
http://www.ebay.co.uk/itm/10A-NOISE-SUPPRE...4cefcf5a31
in the lighter circuit will work? I used one (just preventatively) for the powered sub "from new" so I have no idea if they really work.
Cheers for any advice
Matt Tell someone you love them today because life is short.
But shout it at them in German because life is also terrifying and confusing...
Post #252797 21st Jul 2013 3:43pm
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K9F



Member Since: 12 Nov 2009
Location: Bournemouth
Posts: 9610

United Kingdom 2008 Defender 90 Puma 2.4 XS CSW Stornoway Grey
At the price it's worth a punt anyway. We use similar on the boats and they do work. Thumbs Up If you go through life with your head in the sand....all people will see is an ar5e!!

Treat every day as if it is your last....one day you will be right!!
Post #252842 21st Jul 2013 6:53pm
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ZeDefender



Member Since: 15 Sep 2011
Location: Munich
Posts: 4731

Germany 2011 Defender 110 Puma 2.4 SW Baltic Blue
Cheers Mal - I'll give it a go Thumbs Up Tell someone you love them today because life is short.
But shout it at them in German because life is also terrifying and confusing...
Post #252850 21st Jul 2013 7:15pm
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K9F



Member Since: 12 Nov 2009
Location: Bournemouth
Posts: 9610

United Kingdom 2008 Defender 90 Puma 2.4 XS CSW Stornoway Grey
Matt,

Just remembered. Not so good I found if you're running a subwoofer or auxilliary/pre amp as they are that good it will suppress these too which defeats the object.
Thumbs Up If you go through life with your head in the sand....all people will see is an ar5e!!

Treat every day as if it is your last....one day you will be right!!
Post #252856 21st Jul 2013 7:26pm
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ZeDefender



Member Since: 15 Sep 2011
Location: Munich
Posts: 4731

Germany 2011 Defender 110 Puma 2.4 SW Baltic Blue
Well, the radio/aux is run off its normal loom. Its speaker outputs are tapped to the sub, which takes its power (fused) from the battery with one of these gizmos in between. I guess the radio loom is already noise-reduced somehow.

The power supply for the cradles/phone/music is tapped from the lighter circuit, which I suppose would not normally need to be interference-free, i.e. it's very noisy!

One thing I'm not sure about is where to earth the gizmo. Ideally it should screw to the bodywork but I wonder I I could tap onto another earth cable in there Confused

I admit ignorance about these electronic things, as normally whenever I try to change something, the rest gets worse. However, as you say, its only a few quid and worth a shot, especially if it works in some situations. Only real cost is the time to get the dash apart again Rolling Eyes

Cheers
Matt Tell someone you love them today because life is short.
But shout it at them in German because life is also terrifying and confusing...
Post #252861 21st Jul 2013 7:54pm
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AndyS



Member Since: 18 Aug 2012
Location: London
Posts: 595

United Kingdom 2011 Defender 110 Puma 2.4 XS CSW Sumatra Black
Do your speaker cables run past any of the main power cables for the car, the one that runs to the battery/from alternator? Seeing as there's no ignition system I'd guess it's alternator noise.
Post #252863 21st Jul 2013 7:58pm
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Lou Sparts



Member Since: 15 Apr 2012
Location: Kent
Posts: 1501

United Kingdom 2005 Defender 90 Td5 XS CSW Zambezi Silver
In days of old when i used to run CB radios if we had interferance problems we would run the power supply to the rig through coaxial cable,using the inner core for the power supply and the outer core would act as screening. You could try a similar set up for power to your lighter socket as this is probably where your interferance is coming from. 2005 Td5 90 XS

Steve
Post #252867 21st Jul 2013 8:06pm
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ZeDefender



Member Since: 15 Sep 2011
Location: Munich
Posts: 4731

Germany 2011 Defender 110 Puma 2.4 SW Baltic Blue
AndyS wrote:
Do your speaker cables run past any of the main power cables for the car, the one that runs to the battery/from alternator? Seeing as there's no ignition system I'd guess it's alternator noise.

It's a weird setup, I guess - the aux doesn't normally have any problems with iPhones/mp3 players etc. The radio/aux and its cables seem to be okay. It's just when I use an iPhone which is being charged from the cradle/lighter circuit. As you say, I guess its alternator noise being fed (via the lighter wiring) into the aux. I'll try the gizmo and coaxial cable idea and report back Thumbs Up
Cheers guys
Matt Tell someone you love them today because life is short.
But shout it at them in German because life is also terrifying and confusing...
Post #252879 21st Jul 2013 8:41pm
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WelshGas



Member Since: 01 Oct 2010
Location: Vale of Glamorgan
Posts: 935

Wales 2010 Defender 90 Puma 2.4 XS CSW Santorini Black
I've got a similar problem, but I have wired a triple power and USB socket directly to the battery via a 20amp fuse and ignition switched relay. Definite engine/alternator speed related interference when using my iPod plugged into the USB socket and into the auxillary input on the Head Unit. So I'm interested as to how you get on! Thumbs Up LANDYWATCH

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Post #252883 21st Jul 2013 8:47pm
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blackwolf



Member Since: 03 Nov 2009
Location: South West England
Posts: 17443

United Kingdom 2007 Defender 110 Puma 2.4 DCPU Stornoway Grey
When I used to run a USB device powered from the lighter socket it suffered very badly from (what sounded like generator-induced) interference. Running a feed directly from the battery sorted the problem.
Post #252925 22nd Jul 2013 8:15am
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K9F



Member Since: 12 Nov 2009
Location: Bournemouth
Posts: 9610

United Kingdom 2008 Defender 90 Puma 2.4 XS CSW Stornoway Grey
As mentioned previously using a 'screened' cable (something like SY perhaps if routing underneath the truck) and grounding out the screen should also prevent interference.

Thumbs Up If you go through life with your head in the sand....all people will see is an ar5e!!

Treat every day as if it is your last....one day you will be right!!
Post #252926 22nd Jul 2013 8:22am
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custom90



Member Since: 21 Jan 2010
Location: South West, England.
Posts: 20441

United Kingdom 
What Mal said above is well worth taking on board. The same goes for RCA cable too and if ever you have audio cables and power cables that have to meet ideally they should cross over at a right angle so that there is as little close contact as possible.
I know it involves perhaps a different HU or maybe even not possible to use your device in the way you want to but this is why I use a manufacturer made and "made for iPod" HU & cable which powers the device controls it and plays the music in one plug all running of the HU.
By charging via an external USB and playing via the 3.5mm audio jack you are creating an electrical loop inducing interference noise / electrical noise. (happy to be corrected on this though)

Also make sure the audio jacks are fully inserted as that can cause some noise and also perhaps try a different cable for the sake of it.
Thumbs Up $W33T $0U7H3RN $UG4R
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Post #252952 22nd Jul 2013 10:28am
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Grockle



Member Since: 24 Nov 2008
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United Kingdom 2008 Defender 90 Puma 2.4 XS CSW Tonga Green
Where do you wire into,on ours when you select reverse aload of interference comes through the speakers 2.4 90 XS
1968 1/32 scale Britains 109 Pick up.
Post #252961 22nd Jul 2013 11:10am
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barbel jim



Member Since: 12 Dec 2012
Location: Northants
Posts: 1423

United Kingdom 2005 Defender 90 Td5 HT Tonga Green
Earths are the first place to start. the shorter the better and more effective. I would also check your getting 12+ volts out of your sockets, especially when they are all in use. Someone else has already said they wired them separate which seems like a good idea as well as maybe solving the problem.
Post #252983 22nd Jul 2013 12:10pm
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ZeDefender



Member Since: 15 Sep 2011
Location: Munich
Posts: 4731

Germany 2011 Defender 110 Puma 2.4 SW Baltic Blue
Grockle wrote:
Where do you wire into,on ours when you select reverse aload of interference comes through the speakers

I get exactly the same with the standard radio setup and I am 100% sure it comes from the (cheap) LED reversing lamp I installed.

*UPDATE*
1) First it didn't work...
2) Then it did Thumbs Up

1) The cradles are powered from the lighter terminals so I put the noise-filter between the (+) lighter terminal and the (+) cradle, earthing it to the body via this fuse holder stud:
[URL=]
Click image to enlarge
[/URL]
However, it only cut out 50% of the noise Confused

2) Then I realised I was still using the (-) lighter terminal as earth for the cradle - probably still a source of noise Rolling Eyes
So I took the cradle (-) to the same fuse holder stud and Bingo! Hardly any noise now - my classical collection can again be heard Thumbs Up

Finally, proof of my trust in 3M Velcro:
[URL=]
Click image to enlarge
[/URL]

Admin note: this post has had its images recovered from a money grabbing photo hosting site and reinstated Mr. Green  Tell someone you love them today because life is short.
But shout it at them in German because life is also terrifying and confusing...
Post #254139 28th Jul 2013 5:36pm
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