Whine no more!

ccryder


First off I want to thank this board for their technical expertise and help in everything we do on our St's. Especially Rob H. and Andrew S for suggestions in resolving my alternator whine issues. :)

A little background: I added an XM Roady XTand an AmpliRider to my dash playing through a Starcom intercom. Previously, I ran an MP3 player and AM/FM radio (both non-bike powered) into the Starcom. With the MP3/ AM/FM I had very minimal alternator whine. I could only hear it when the audio sources were turned off.

When I added the XM and AmpliRider I had bad alternator whine that was RPM and load dependent. When I would turn on:, Turn signals+ Windshield motor+ 1100X+ 004XT the volume of the whine would greatly increase.

Since my Blue Sea box is wired directly to the battery ("+" lead two 12ga wires, "-" lead two 14ga wires), and the Blue Sea box powers the Dash electrics, Rob H. and Andrew S. suggested I try two things:
1: Ground the Blue Sea "-" buss to the frame.
2: If there was anyway to twist the wires powering the Blue Sea box, twist them as much as possible.

So I took their advice, I twisted the "-" buss wires and bolted them to the frame. I twisted the two "+" wires and my whine is reduced over 95% It is back to where it was previously with the MP3/ AM/FM. Well within toloerable range, way below the background wind noise at 30mph.

MAGIC! Well maybe not magic, but good seat-of-the-pants engineering. :bow1:

Thanks again to all.

Neil S.
 

Attachments

  • BSAuncoveredRed30.jpg
    BSAuncoveredRed30.jpg
    67.8 KB · Views: 273
  • BlueSeaAuxTXT.jpg
    BlueSeaAuxTXT.jpg
    166.5 KB · Views: 240
Clarification

CC;
All you did was twist the double + and - leads to the Blue Sea? Too easy.

I'm using a JMCB and the whine is always there. I guess it's time to clean up that mess of wires and get something like the Blue Sea.
 
That's why I was plesantly surprised, since this fix was almost too easy. I already had a pair of wires going to each of the terminals so it was easy to just twist each pair together.

If you have a negative and a positive power lead going to your J&M. just twist those insulated wires together. I don't think the issue was if I had the Blue Sea box. The issue was I had untwisted wires that could pick up the "noise".

I used black tape and spiral wrap to cover my twisting of wires.

Yes I was fully expecting to have to take further measures to eliminate the whine.

Time2Fly

Neil S.
 
This is very interesting but when you say twisting, is this like a pair of phone wires? Also how did you twist them, chuck them up in a drill?
 
Great to hear man, I'm glad that it worked for you. :D

Yes, you could just hook them up in a drill and twist them, but don't over do it and break the wires.

I would be interested to know which helped more, the twisting or grounding to the frame instead of the battery.
 
I had a lot of noise when grounded to the battery . I eliminated a great deal of this noise by taking all my grounds to a terminal block and then I ran a 12ga wire to the same grounding point as the factory wiring. This twisting may remove the last bit of noise I have.
 
You know I've been dealing with networks and twisted pair cabling for the better part of my career and understand why twisting the pairs cancel noise interference but I'm greatly surprised at the amount of an affect that has on the noise issue.

You can bet I'll be doing this on some of my future installs. I don't have the energy to do it to what's already wired. Twisted pair uses differential pairs (a + and a -) for transmit and another pair for receive. These twists are the key to reducing noise interference and allows longer tranmission lines. Cat 5 was a good try at a standard but Anixter's research in this area led to the higher levels of industry standard CAT cables.

This is also the first time that I've heard to NOT ground to the battery terminal. I think I'll have to redo my grounding point. I wish I understood why this has an affect on noise injection but I'm learning new things everyday. All I have is theory and some practical applications to back up what I post so it's interesting when others with more expierence chime in with their background and solutions. I'm sure some people with more expierence look at some of my posts and just shake their head and never bother to point out the pieces that in their opinion, or in fact, are just wrong. I wish they would as it makes my future articles better.

Enough babble. I'll start twisting wires as soon as it gets above friggin' 0. Brrr.

Curt
 
Last edited:
crazykz said:
You know I've been dealing with networks and twisted pair cabling for the better part of my career and understand why twisting the pairs cancel noise interference but I'm greatly surprised at the amount of an affect that has on the noise issue.

You can bet I'll be doing this on some of my future installs. I don't have the energy to do it to what's already wired. Twisted pair uses differential pairs (a + and a -) for transmit and another pair for receive. These twists are the key to reducing noise interference and allows longer tranmission lines. Cat 5 was a good try at a standard but Anixter's research in this area led to the higher levels of industry standard CAT cables.

This is also the first time that I've heard to NOT ground to the battery terminal. I think I'll have to redo my grounding point. I wish I understood why this has an affect on noise injection but I'm learning new things everyday. All I have is theory and some practical applications to back up what I post so it's interesting when others with more expierence chime in with their background and solutions. I'm sure some people with more expierence look at some of my posts and just shake their head and never bother to point out the pieces that in their opinion, or in fact, are just wrong. I wish they would as it makes my future articles better.

Enough babble. I'll start twisting wires as soon as it gets above friggin' 0. Brrr.

Curt
Click to expand...


As to why not to ground to the battery....I'm really not sure, I just know that it works. :rolleyes:
My guess is that the battery post is not a stable connection. The battery post mounted in plastic, I'm sure it vibrates to some extent and the battery can't be held completely still.
Sorry I can't help more.
 
NCrider said:
As to why not to ground to the battery....I'm really not sure, I just know that it works. :rolleyes:
My guess is that the battery post is not a stable connection. The battery post mounted in plastic, I'm sure it vibrates to some extent and the battery can't be held completely still.
Sorry I can't help more.
Click to expand...

I think it may have something to do that any electrical noise that's injected into the system may be picked up at the battery ground but I would think the same would be for the frame but maybe not. No clue. Sometimes there isn't one solution and people need to find what works best for them. I may end up moving my ground to where it connects to the frame with a thick cable even though I don't have noise issues now. I would like to make sure I don't as I add some other things over winter.

Curt
 
Interesting thread. I've heard the terms twisted and twisted pair and didn't know what they meant before. Anyway, as I prepare to install my Roady XT and my Starcom Advance, I want to take advantage of this to avoid noise. I don't completely understand what to do :confused: so I have a few questions:

1. Should I twist the two "-" leads (one from the Starcom and one from the Roady) together and then twist the two "+" ones together, but keep the + & - leads separate?

2. Should the + & - from each device be twisted together, but the pairs of leads from each device be separated?

3. Should all four (the + & -) leads from both devices be twisted together?

4. None of the above?

TIA
 
The negative post of the battery is the return path of charging from the alternator. In reality it is the second noisiest point in any vehicle electrical system. The nosiest would be the case of the alternator itself.

I have about 20 years experience when it comes to the installation of aftermarket electronic componentts on vehicles and I can tell you that the best way to ground audio components is as follows.

-Ground each unit individually from each other at a point on the frame close to the component.
-Do NOT ground to the battery.
-Do NOT ground to the factory battery ground point.
-Use twisted pair cable for audio connections

Barring a bad audio component, if you follow this as a set of rules you should end up noise free.

One other thing that you may consider is when an amplifier is used, make sure that you use low output from the component and then use the amplifier to get more volume, that will eliminate some possible noise issues that arise from using multiple sources.
 
Last edited:
wjbertrand said:
1. Should I twist the two "-" leads (one from the Starcom and one from the Roady) together and then twist the two "+" ones together, but keep the + & - leads separate?
Click to expand...
You know I'm not sure but I would think the two wires should be from the same device so the more common application is twisting the positive and negative wire of a unit. I would think twisting two wires that run parallel to each other that have the same amount of noise in them would cancel each other regardless of the voltage on them but maybe Rob can add more to that. The basic theory is that noise injects current into a line which results in you hearing noise. The current injected into the line flows in one direction (known as the right hand rule). By twisting the wires though you created loops. Think about what 2 sine waves look like that are 180 degrees out of phase.
32NE0130.GIF

Imagine the radio interference is going through the loops in the waves (this would mean that the noise is coming or going straight out of the page at you or away from you). When the interference goes through one loop it injects current in one direction. When noise goes through the loop next to it, it will inject current in the opposite direction. There is an equal amount of radio interference going through each loop in the twisted wires. Which means that the opposing currents that are induced by the noise cancel each other out. I don't know why I'm writing this because I don't think I even understand what I'm saying but there it is. In simple terms by twisting the pairs it causes the radio interference to cancel itself out. That doesn't answer your question but you can experiment with it to see what the results are I guess. Start with what's conveniant.

wjbertrand said:
2. Should the + & - from each device be twisted together, but the pairs of leads from each device be separated?
Click to expand...
This would be the more common practice but again I'm not sure about the physics behind it from that perspective.

wjbertrand said:
3. Should all four (the + & -) leads from both devices be twisted together?
Click to expand...
I would twist them individually.

wjbertrand said:
4. None of the above?
Click to expand...
See #1. ;)

Curt
 
Last edited:
crazykz said:
You know I'm not sure but I would think the two wires should be from the same device so the more common application is twisting the positive and negative wire of a unit. I would think twisting two wires that run parallel to each other that have the same amount of noise in them would cancel each other regardless of the voltage on them but maybe Rob can add more to that. The basic theory is that noise injects current into a line which results in you hearing noise. The current injected into the line flows in one direction (known as the right hand rule). By twisting the wires though you created loops. Think about what 2 sine waves look like that are 180 degrees out of phase.
32NE0130.GIF

Imagine the radio interference is going through the loops in the waves (this would mean that the noise is coming or going straight out of the page at you or away from you). When the interference goes through one loop it injects current in one direction. When noise goes through the loop next to it, it will inject current in the opposite direction. There is an equal amount of radio interference going through each loop in the twisted wires. Which means that the opposing currents that are induced by the noise cancel each other out. I don't know why I'm writing this because I don't think I even understand what I'm saying but there it is. In simple terms by twisting the pairs it causes the radio interference to cancel itself out. That doesn't answer your question but you can experiment with it to see what the results are I guess. Start with what's conveniant.


This would be the more common practice but again I'm not sure about the physics behind it from that perspective.


I would twist them individually.


See #1. ;)

Curt
Click to expand...

Thanks Curt!
 
Curt, you still may be full of it but, it's a pretty good explanation. Heck what do I know I'm just an ME and farkleaddict!

I am glad this has helped some others since I know I'm not the only having this problem. Sometimes our best intentions tend to screw things up ie: I did not think it was good to ground to an aluminum frame (note: my ground for my Blue Sea box now goes to the steel part of the frame at a bolt that holds the front seat support)

So now I twist to my hearts content and can't be accused of being "twisted", at least for that reason.

Signing off in the heartland of Oklahoma, McAlester. Getting ready for a job interview tomorrow AM. Wish me luck. :eek:

Later
Neil S.
 
If you are talking power you can twist or not twist, actually the best is to not twist. (by twisting you create a sort of filter, but noise does not really get into your power wire that way...)

Have a short ground to the frame and then run the power to the battery.

The twisting really comes into play for audio signal.

Let's solve the power question first.

Is everyone with me?
 
stoc445 said:
This is very interesting but when you say twisting, is this like a pair of phone wires? Also how did you twist them, chuck them up in a drill?
Click to expand...

For those that have never raced, nor prepped a race bike, I can assure you'll be impressed with the simple mechanical ability of the device available below:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=45341

Twists wire up with a couple of quick pulls, and I use the pliers and wire for a load of other applications (hanging pictures for example).

Eliminates the really annoying over/under situation completely.

Pags
 
Rob Hephner said:
If you are talking power you can twist or not twist, actually the best is to not twist. (by twisting you create a sort of filter, but noise does not really get into your power wire that way...)

Have a short ground to the frame and then run the power to the battery.

The twisting really comes into play for audio signal.

Let's solve the power question first.

Is everyone with me?
Click to expand...

OK, now I'm lost again. :confused:
 
Well I'm not confused but I don't know which was the culprit. I know that with years of engineering background I should have done a step by step process to determine which was the real solution but, I was in a hurry trying to do this and that.

Maybe this weekend I'll try moving the "-" back to the battery to see if that was the solution. I only have to remove the seats, and side cover. I may be doing a thermostat R&R this weekend also.

Time2Work
Neil S.
 
You must log in or register to reply here.
Back
Top Bottom