Ground Loop Isolator - BMW Luxury Touring Community
 
LinkBack Thread Tools Display Modes
post #1 of 24 Old Aug 28th, 2008, 1:39 pm Thread Starter
Senior Member
 
Join Date: Jun 2004
Location: Redlands, CA, USA
Posts: 439
Ground Loop Isolator

I have been using earbuds for awhile on the J&M intercom. I had a significant amount of extra noise from the alternator and sparkplugs. I added a ground loop isolator. It reduced this noise but did not eliminate. Has anyone tried putting two ground loop isolators in series? Will this eliminate more noise or cause a mushroom cloud?
BEhrler is offline  
Sponsored Links
Advertisement
 
post #2 of 24 Old Aug 28th, 2008, 2:23 pm
Senior Member
 
Ajlelectronics's Avatar
 
Join Date: Dec 2006
Location: Gloucester, Gloucestershire, England
Posts: 361
Re: Ground Loop Isolator

Quote:
Originally Posted by BEhrler
I have been using earbuds for awhile on the J&M intercom. I had a significant amount of extra noise from the alternator and sparkplugs. I added a ground loop isolator. It reduced this noise but did not eliminate. Has anyone tried putting two ground loop isolators in series? Will this eliminate more noise or cause a mushroom cloud?
Once you have isolated then you have isolated. Putting additional units in series will achieve nothing more than lightening your wallet.

Interference issues can be a bitch to resolve. First thing to do is make sure you have good earth connections everywhere. The size of power cables and where they connect can also have a bearing.

Is it possible you have another unit to isolate? On mine (Starcom) I had to isolate the radio and comms inputs. There is the slightest trace of alternator whine left but nothing ridiculous. Can you disconnect everything from the intercom and see if it goes quiet? If it does, reconnect one by one until it re-appears.

Just pussin' through.

Last edited by Ajlelectronics; Aug 28th, 2008 at 2:24 pm. Reason: Spelling
Ajlelectronics is offline  
post #3 of 24 Old Aug 28th, 2008, 6:13 pm
Senior Member
 
taylorjn's Avatar
 
Join Date: May 2002
Location: Minneapolis, MN, USA
Posts: 1,391
Re: Ground Loop Isolator

Quote:
Originally Posted by BEhrler
I have been using earbuds for awhile on the J&M intercom. I had a significant amount of extra noise from the alternator and sparkplugs. I added a ground loop isolator. It reduced this noise but did not eliminate. Has anyone tried putting two ground loop isolators in series? Will this eliminate more noise or cause a mushroom cloud?
What year LT? I got noise in the ears from mine as well. If you have VoiceII, you can lower the gain on your headset, effectively killing the whine. Mine was alternator, according to a tech, which would not be noticed without earplug speakers.

Jim Taylor
Minneapolis
07 Black LT "Dancing Heart", 03 Quantum "Ice"
02 Black LTC "Raven" (RIP 8/26/06)
08 Can-Am Spyder (hers) (#731)
taylorjn is offline  
 
post #4 of 24 Old Aug 28th, 2008, 8:12 pm
Senior Member
 
scurrie's Avatar
 
Join Date: Jul 2005
Location: Auburn, WA, USA
Posts: 173
Re: Ground Loop Isolator

Where did you place the isolator, and what other devices do you have connected? You may still have a ground loop from another device, like a cell phone that is powered from the bike, or a radar detector.

-Scott

2005 LT
ARS NS7C
BMWMOA #113753
All Roads Lead To Roads...
scurrie is offline  
post #5 of 24 Old Aug 28th, 2008, 11:43 pm
 
Join Date: Feb 2004
Posts: 4,905
Re: Ground Loop Isolator

I have successfully removed all of the whine/buzz/noise out of my intercom systems on my LT and GT with the use of GLI cables. The trick is to use one on EVERY device that is powered by the bike.

And just so I'm clear ... I use GLI cables on the audio cables, NOT the power cables. Trying to get rid of noise by cleaning up the power source has NEVER worked for me. YMMV
messenger13 is offline  
post #6 of 24 Old Aug 29th, 2008, 10:50 am Thread Starter
Senior Member
 
Join Date: Jun 2004
Location: Redlands, CA, USA
Posts: 439
Re: Ground Loop Isolator

Quote:
Originally Posted by messenger13
I have successfully removed all of the whine/buzz/noise out of my intercom systems on my LT and GT with the use of GLI cables. The trick is to use one on EVERY device that is powered by the bike.

And just so I'm clear ... I use GLI cables on the audio cables, NOT the power cables. Trying to get rid of noise by cleaning up the power source has NEVER worked for me. YMMV
You stated that you use a GLI cable on every device that is powered by the bike is this every device that connects to the sound system. ie, radar detector, GPS, XM radio etc. If this is true then you use multiple GLI cables correct? I'm using only one GLI device and it's connected directly inline with my earbuds. It seems to me that the GLI inline with the earbuds would do the same thing as a GLI on every device. However, it does not. I still get a small amount of alternator whine and sparkplug buzz. Please explain the difference. Thanks.
BEhrler is offline  
post #7 of 24 Old Aug 29th, 2008, 11:28 am
Senior Member
 
zippy_gg's Avatar
 
Join Date: Jun 2004
Location: Kennesaw, GA, USA
Posts: 8,123
Re: Ground Loop Isolator

Also whatever you do, do NOT use frame tabs as ground. Instead run a cable back to the battery if you have to, or power everything via a fuse box such as a Blue Sea which has a ground wire going back to the battery.

Gilles & Kathy
BMWMOA# 154719
IBA# 71594
2011 Ostra Gray RT
06 Mercedes-Benz E350 Estate (parts and people hauler)
2012 BMW X3 (parts and people hauler)
86 Porsche 911 Cabriolet (my "new" baby)



For her I climbed the highest mountain!
For her I swam across the deepest ocean!
For her I walked through the largest desert!
And then she left me... She said I was never home!!!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
zippy_gg is offline  
post #8 of 24 Old Aug 29th, 2008, 12:10 pm
 
Join Date: Feb 2004
Posts: 4,905
Re: Ground Loop Isolator

Quote:
Originally Posted by zippy_gg
Also whatever you do, do NOT use frame tabs as ground. Instead run a cable back to the battery if you have to, or power everything via a fuse box such as a Blue Sea which has a ground wire going back to the battery.
A good point. However, I've still experienced all sorts of ground loop issues even though I've never used any part of the frame as a grounding point. That's why I am convinced that ground loop issues are best confronted on the audio side of the equation, and not the power source side.


Quote:
Originally Posted by BEhrler
You stated that you use a GLI cable on every device that is powered by the bike is this every device that connects to the sound system. ie, radar detector, GPS, XM radio etc. If this is true then you use multiple GLI cables correct?
This is correct. Each bike-powered device that has an audio input into the intercom system gets it's own GLI cable. (i.e. Garmin GPS, iPod, ICOM GMRS, cellphone, Valentine One radar detector.) These cables can be bought or homemade ... with a wide range of costs.


Quote:
Originally Posted by BEhrler
I'm using only one GLI device and it's connected directly inline with my earbuds. It seems to me that the GLI inline with the earbuds would do the same thing as a GLI on every device. However, it does not. I still get a small amount of alternator whine and sparkplug buzz. Please explain the difference. Thanks.
The difference, as I see it, is that you are trying to solve the problem after it's a problem. You are trying to remove the ground loop issues after they've been amplified in your intercom system. Removing the whine/buzz from the audio signal before they are introduced to your intercom insures a clean output into your headset or earbuds. I look at my method as more of 'a solution', while using a GLI cable that's headed to your helmet as more of a Band-Aid. No offense.

Lastly, I do need to point out that rerouting an audio cable is yet another way to eliminate unwanted noise. I was still picking up static in my Valentine One's audio cable, even with a GLI cable installed. I moved it from the left side of my GT to the right and all of the noise was GONE.
messenger13 is offline  
post #9 of 24 Old Aug 29th, 2008, 2:22 pm
Senior Member
 
mrbiker's Avatar
 
Join Date: Jul 2007
Location: Los Angeles, CA, USA
Posts: 226
Re: Ground Loop Isolator

Quote:
Originally Posted by messenger13
A good point. However, I've still experienced all sorts of ground loop issues even though I've never used any part of the frame as a grounding point. That's why I am convinced that ground loop issues are best confronted on the audio side of the equation, and not the power source side.


This is correct. Each bike-powered device that has an audio input into the intercom system gets it's own GLI cable. (i.e. Garmin GPS, iPod, ICOM GMRS, cellphone, Valentine One radar detector.) These cables can be bought or homemade ... with a wide range of costs.


The difference, as I see it, is that you are trying to solve the problem after it's a problem. You are trying to remove the ground loop issues after they've been amplified in your intercom system. Removing the whine/buzz from the audio signal before they are introduced to your intercom insures a clean output into your headset or earbuds. I look at my method as more of 'a solution', while using a GLI cable that's headed to your helmet as more of a Band-Aid. No offense.

Lastly, I do need to point out that rerouting an audio cable is yet another way to eliminate unwanted noise. I was still picking up static in my Valentine One's audio cable, even with a GLI cable installed. I moved it from the left side of my GT to the right and all of the noise was GONE.
I agree with almost everything here, but would add one more tip;

All electronics added to the bike should have their ground (on the power side) brought to the same place and grounded in one spot. You could bring 2,3,4 or however many ground wires you have for each of your electronics, put a ring terminal on each one, then put a bolt through them all and bold it down to a superb ground. THE VERY BEST PLACE is the spot where the alternator is grounded.

Electronic theory dictates this should eliminate all whine in its' entirety. Whether it does or not, you'll have to find out, however, this would be the biggest factor in reducing it to either nothing, or to a point where GLI's installed on the audio side get rid of it completely.

I have done this on my 2005, using the battery negative as the ground, and I have no noise whatsoever.

Good luck.

mike p
2005 BMW K1200LT (got it in July 2007)
2002 Kawasaki Ninja ZX-12R (parked next to the LT)
1982 Suzuki GS-750EZ (paid $500
for it in 1985, sold it for $450 in 2000)
1978 Honda CB-500F (sold in 1980)
1976 Honda CB-400F (drowned to
death in the blizzard of 1978 in Boston)
mrbiker is offline  
post #10 of 24 Old Aug 29th, 2008, 2:51 pm
Senior Member
 
scurrie's Avatar
 
Join Date: Jul 2005
Location: Auburn, WA, USA
Posts: 173
Re: Ground Loop Isolator

Quote:
Originally Posted by messenger13
The difference, as I see it, is that you are trying to solve the problem after it's a problem. You are trying to remove the ground loop issues after they've been amplified in your intercom system. Removing the whine/buzz from the audio signal before they are introduced to your intercom insures a clean output into your headset or earbuds. I look at my method as more of 'a solution', while using a GLI cable that's headed to your helmet as more of a Band-Aid.
Exactly. Placing an isolator in the earbud lead will just change the impedance of the output circuit, probably really screwing up the frequency response, which is why you hear some difference. The problem has to be corrected at the amplifier (intercom) input. Remember that audio amplifiers are taking very small AC signals and amplifying them. Small differences in the grounds create a small potential that is then amplified right along with the music. Taking all the grounds to the same point should in theory fix the problem, but in practice there is often still a small difference in the ground impedance. Add to that the fact that you have systems all over the bike like the alternator, ignition, and fuel injectors connected to various ground points around the bike that are creating huge current flows compared to the audio from an iPod. No wonder we hear noise. The best solution is to isolate the audio from the noise on the bike ground, and that is what the isolation transformers do. In professional audio, we use low impedance balanced (3 wire) connections on the mics and other equipment to isolate the audio from ground. iPods and other consumer audio devices use unbalanced (2 wire) connections, and the ground is typically common with the negative power source.

If the audio source has no connection to the bike ground, like a battery powered iPod, there is no ground loop, but as soon as you connect the power adapter to it, it now has a ground connection to the bike and the potential for a ground loop.

-Scott

2005 LT
ARS NS7C
BMWMOA #113753
All Roads Lead To Roads...
scurrie is offline  
post #11 of 24 Old Aug 30th, 2008, 10:23 am Thread Starter
Senior Member
 
Join Date: Jun 2004
Location: Redlands, CA, USA
Posts: 439
Re: Ground Loop Isolator

All of the above sounds like great advice. Where do I start and where do I get GLI cables. I have no clue.
Thanks
BEhrler is offline  
post #12 of 24 Old Aug 30th, 2008, 11:10 am
Senior Member
 
scurrie's Avatar
 
Join Date: Jul 2005
Location: Auburn, WA, USA
Posts: 173
Re: Ground Loop Isolator

Quote:
Originally Posted by BEhrler
All of the above sounds like great advice. Where do I start and where do I get GLI cables. I have no clue.
Thanks
Start by figuring out what you need. How many devices do you need to isolate? iPod, cell, radar detector, GPS, Sat receiver, FRS/GMRS, CB? Then determine which are stereo sources and which are mono.

If you are good with a soldering iron, you can roll your own pretty cheap, if not, you will need to buy them at a car stereo shop, Radio Shack, or some other supplier (I roll my own...). The store bought isolators will likely have the wrong connectors for your devices, so you will need the appropriate adapters too. Then you have to find a place to hide them all.

In my opinion it is not worth the money to buy high quality "audiophile" isolators. The signal to noise ratio on your bike (70MPH wind blowing past your helmet), and the quality of your helmet speakers means you won't hear the difference.

The device from Radio Shack, part 270-054, works fine, but has the wrong connectors for most devices (it has RCA type instead of the typical 3.5mm plugs). It's not to hard to change them if you can handle a soldering iron. If not, you will need adapters to get the right connections, but these will increase the size of the package you need to hide somewhere. The 270-054 is a stereo isolator, so it can handle one stereo device like a sat receiver, or two mono devices like GPS and radar detector.

There are companies on the web that sell isolators with 3.5MM plugs, google a bit and you will find them.

Try to keep the isolators away from other electrical cables on the bike, since they can actually pick up noise from them. A transformer is an inductive device. It is essentially two coils separated by a ferric core. The audio from your device is fed to one coil which creates an electro-magnetic field that is inductively coupled to the other coil, which is then connected to the amplifier. This is how it isolates the ground, there is no direct connection between the two coils. But, placed too close to a source of strong electrical noise, like say a spark plug cable, some of that spark energy can be induced into the coils as well.

-Scott

2005 LT
ARS NS7C
BMWMOA #113753
All Roads Lead To Roads...
scurrie is offline  
post #13 of 24 Old Aug 30th, 2008, 11:18 am Thread Starter
Senior Member
 
Join Date: Jun 2004
Location: Redlands, CA, USA
Posts: 439
Re: Ground Loop Isolator

The only sound source items I use is an XM radio, a Navigator II and a GMRS radio. The GMRS radio does not use the bike as a power source. It uses batteries. I can isolate the XM easily and will try that first. If I remove the GPS from the bike and the whine goes away does that mean that it's the GPS? Or will unhooking the GPS be of no consequence to the noise even if it's from the GPS circuit? That leaves the intercom. Where in the world do I start with that? Thanks for all of your inputs.
BEhrler is offline  
post #14 of 24 Old Aug 30th, 2008, 12:14 pm
Senior Member
 
scurrie's Avatar
 
Join Date: Jul 2005
Location: Auburn, WA, USA
Posts: 173
Re: Ground Loop Isolator

Quote:
Originally Posted by BEhrler
The only sound source items I use is an XM radio, a Navigator II and a GMRS radio. The GMRS radio does not use the bike as a power source. It uses batteries. I can isolate the XM easily and will try that first. If I remove the GPS from the bike and the whine goes away does that mean that it's the GPS? Or will unhooking the GPS be of no consequence to the noise even if it's from the GPS circuit? That leaves the intercom. Where in the world do I start with that? Thanks for all of your inputs.
There should be no noise in the intercom with the GPS, XM and GMRS disconnected from it. If there is, then you have a different problem, the noise is coming from the power source to the intercom and you will need a power filter on it, and/or take the power connections direct to the battery (which is where they should be anyway).

You can try unplugging each device from the intercom one at a time to see if it is only one device that is causing the problem, but most likely, you will need to isolate both the XM and GPS. If the GMRS radio runs off its internal battery, and does not have an external antenna that is grounded to the frame, it is probably not causing the noise. As for removing the GPS unit, it depends how the GPS cabling works. If the ground connections are made inside the GPS unit, then removing it should remove the noise. But, if the grounds are common in the connecting cable itself (most likely), then removing the GPS unit will have no effect.

-Scott

2005 LT
ARS NS7C
BMWMOA #113753
All Roads Lead To Roads...
scurrie is offline  
post #15 of 24 Old Aug 30th, 2008, 6:13 pm Thread Starter
Senior Member
 
Join Date: Jun 2004
Location: Redlands, CA, USA
Posts: 439
Re: Ground Loop Isolator

I've tried posting twice to this thread and nothing has come through. Here goes number three.

I have unhooked everything that has sound that inputs to the intercom. I still have the alternator whine. I have no clue what to do after the stingray is removed. What wires go to the intercom? Do I route the ground only to the battery if this is a ground loop problem? Do I route both power and ground? Will one of those filters work on the alternator wire to the battery? I'm assuming it's the large red wire to the battery??? Is the alternator whine from a ground loop or should it be a loud buzz. As you can see I'm clueless. Thanks for the help?
BEhrler is offline  
post #16 of 24 Old Aug 31st, 2008, 1:30 pm
Senior Member
 
scurrie's Avatar
 
Join Date: Jul 2005
Location: Auburn, WA, USA
Posts: 173
Re: Ground Loop Isolator

Quote:
Originally Posted by BEhrler
I have unhooked everything that has sound that inputs to the intercom. I still have the alternator whine.
OK, then like I said previously, you have a different problem, not a ground loop. You need to look at the power wiring to the intercom.
Quote:
Originally Posted by BEhrler
I have no clue what to do after the stingray is removed. What wires go to the intercom? Do I route the ground only to the battery if this is a ground loop problem? Do I route both power and ground?
Not sure why you want to take the stingray off, unless the intercom is mounted there. If that is the case, how did you disconnect the audio devices?! First thing I would do is make sure the negative lead from the intercom goes direct to the battery. You might want to take the positive lead direct to the battery too as a test, however, this would power the intercom all the time and you run the risk of killing the battery (unless the J&M turns off when you disconnect the helmet). More on this below...
Quote:
Originally Posted by BEhrler
Will one of those filters work on the alternator wire to the battery? I'm assuming it's the large red wire to the battery???
Don't mess with your alternator wiring, or any of the factory wiring for that matter. The problem is with the non-factory J&M intercom.[/QUOTE]
Quote:
Originally Posted by BEhrler
Is the alternator whine from a ground loop or should it be a loud buzz.
Alternator noise is a high pitched whining sound that changes pitch with the speed of the engine. It can be caused by a ground loop as noted in the previous posts, or it can come in on the power lead to the intercom unit. Again, if you have really disconnected all of the inputs to the intercom (at the intercom unit itself, not at the audio devices) and still have noise, it is coming from the power source. You will need a different filter for this. Use something similar to the PAC ANS-80 (do a google search) on the positive power lead to the intercom, and make sure the negative lead goes direct to the battery.
Quote:
Originally Posted by BEhrler
As you can see I'm clueless.
And at this point it may be best if you take the bike to someone who understands these installations. I assume you did not install the intercom, whoever did may have made several mistakes.

-Scott

2005 LT
ARS NS7C
BMWMOA #113753
All Roads Lead To Roads...
scurrie is offline  
post #17 of 24 Old Aug 31st, 2008, 5:08 pm Thread Starter
Senior Member
 
Join Date: Jun 2004
Location: Redlands, CA, USA
Posts: 439
Re: Ground Loop Isolator

I have the J&M dealer installed intercom. The dealer has been unable to find the problem. BMW tech said the alternator noise was not a problem. If I use the J&M helmet headset it's not as noticable. However, with the earbuds it's very loud.
I just unhooked removed the GPS and the XM radio from the system. I did not unhook them from the intercom. The XM is wired into the CD circuit with a Soundgate device.
My next step is to find the power and ground leads to the intercom and try re-routing as you suggested.
I googled the PAC ANS-80 and it says to install inline from the alternator to the battery. You suggested that I not do this but put it inline with the intercom. What is the difference.
I have not removed the Soundgate. I will try that before going further.
Thanks for the help. This has been an elusive problem.
BEhrler is offline  
post #18 of 24 Old Aug 31st, 2008, 5:30 pm
Senior Member
 
STYLNLT's Avatar
 
Join Date: Jun 2005
Location: Long Beach, Ca, USA
Posts: 128
Re: Ground Loop Isolator

Alittle input that might help...

Another common problem of hum/ground loop noise, is having to many uncommon grounds. Mixing Earth ground as mentioned earlier is fine, as long as all other components do the same thing. However, if you have a mix, then is when you run into problems.

I find its best to isolate your grounds, keeping them stricktly to whatever the battery terminal terminates to in the first place. If this is the frame, then your back to the earth ground solution. However if the ground is kept within the wiring harness, then follow that method of grounding. Which is what my 00 LT has.

I would verify what ground solution the comm system is using and work accordingly.

Isolators, or Ferrets as they've been refered to in the past, help mostly with RF induced noise. Additionally, there are ground loop isolators with built in capacitors (rather large) that you can purchase from Radio Shack, that have RCA connectors on them, that you could attempt to use as well.
STYLNLT is offline  
post #19 of 24 Old Aug 31st, 2008, 6:48 pm Thread Starter
Senior Member
 
Join Date: Jun 2004
Location: Redlands, CA, USA
Posts: 439
Re: Ground Loop Isolator

Quote:
Originally Posted by STYLNLT
Alittle input that might help...

Another common problem of hum/ground loop noise, is having to many uncommon grounds. Mixing Earth ground as mentioned earlier is fine, as long as all other components do the same thing. However, if you have a mix, then is when you run into problems.

I find its best to isolate your grounds, keeping them stricktly to whatever the battery terminal terminates to in the first place. If this is the frame, then your back to the earth ground solution. However if the ground is kept within the wiring harness, then follow that method of grounding. Which is what my 00 LT has.

I would verify what ground solution the comm system is using and work accordingly.

Isolators, or Ferrets as they've been refered to in the past, help mostly with RF induced noise. Additionally, there are ground loop isolators with built in capacitors (rather large) that you can purchase from Radio Shack, that have RCA connectors on them, that you could attempt to use as well.
I don't have a hum. I have an alternator whine. Will the above apply to that?
BEhrler is offline  
post #20 of 24 Old Aug 31st, 2008, 6:57 pm
 
Join Date: Feb 2004
Posts: 4,905
Re: Ground Loop Isolator

Quote:
Originally Posted by zippy_gg
Also whatever you do, do NOT use frame tabs as ground. Instead run a cable back to the battery if you have to, or power everything via a fuse box such as a Blue Sea which has a ground wire going back to the battery.
Quote:
Originally Posted by messenger13
A good point. However, I've still experienced all sorts of ground loop issues even though I've never used any part of the frame as a grounding point. That's why I am convinced that ground loop issues are best confronted on the audio side of the equation, and not the power source side.
Quote:
Originally Posted by mrbiker
I agree with almost everything here, but would add one more tip;

All electronics added to the bike should have their ground (on the power side) brought to the same place and grounded in one spot.
Quote:
Originally Posted by scurrie
Taking all the grounds to the same point should in theory fix the problem...
Quote:
Originally Posted by STYLNLT
Another common problem of hum/ground loop noise, is having to many uncommon grounds. Mixing Earth ground as mentioned earlier is fine, as long as all other components do the same thing. However, if you have a mix, then is when you run into problems.

I find its best to isolate your grounds, keeping them stricktly to whatever the battery terminal terminates to in the first place.

I'm just wondering how many times we're going to hear about grounding all the devices to one location (the battery) in one thread???

messenger13 is offline  
post #21 of 24 Old Aug 31st, 2008, 7:02 pm
Senior Member
 
STYLNLT's Avatar
 
Join Date: Jun 2005
Location: Long Beach, Ca, USA
Posts: 128
Re: Ground Loop Isolator

Yes. I say hum, others refer to it as whine or buzz. Unless your wires are lying on the alternator directly were your likely to be picking up inductive whine, then focus on the ground issue.

Additionally, I would check all accessory grounds to insure they are all on the same grounding technique. It may/may not be a bit much at this point depending upon how much you have installed on the bike, but it will make it easier for diagnosing down the road.

I will note that you could also have a problem with the comm unit itself, if faulty. I have come across a tracer on a circuit board that solder was touching that caused an intermitant problem. One would hope things like this are QC'd properly, but, as they say, it happens.
STYLNLT is offline  
post #22 of 24 Old Aug 31st, 2008, 7:18 pm
Senior Member
 
scurrie's Avatar
 
Join Date: Jul 2005
Location: Auburn, WA, USA
Posts: 173
Re: Ground Loop Isolator

Quote:
Originally Posted by BEhrler
I googled the PAC ANS-80 and it says to install inline from the alternator to the battery. You suggested that I not do this but put it inline with the intercom. What is the difference.
You're right, the PAC ANS-80 was not a good suggestion. I was thinking more along the lines of PAC ENF-5 or American International's S15A and similar devices (Radio Shack used to sell one, but I can't find it on the web site anymore) which are installed inline with the positive lead to the intercom. There are two leads and a ground connection, one lead goes to the power source (battery) and the other lead goes to the positive lead on the intercom, and the ground lead goes to the battery negative terminal.
Quote:
Originally Posted by STYLNLT
Isolators, or Ferrets as they've been refered to in the past, help mostly with RF induced noise. Additionally, there are ground loop isolators with built in capacitors (rather large) that you can purchase from Radio Shack, that have RCA connectors on them, that you could attempt to use as well.
Wrong, ground loop isolators are inductive devices, not capacitive devices, and do not help with RF interference. There are capacitive filters you can install to reduce/eliminate RF interference, but they are NOT ground loop isolators. Also, ferrite cores that you wind the cables through create inductive chokes to reduce RF interference, but again, these are not ground loop isolators. A ground loop is a very specific situation created by different ground potentials between two (or more) audio devices. Ground loops are very common on motorcycle intercom installations, but there are indeed other types of noise that can plague these systems. We have been trying to figure out which type of noise we are dealing with here (which is not so easy via the forum).

We should probably move this thread to the intercom forum (if not take it offline), the rest of the folks out there are probably getting tired of reading this!

-Scott

2005 LT
ARS NS7C
BMWMOA #113753
All Roads Lead To Roads...
scurrie is offline  
post #23 of 24 Old Aug 31st, 2008, 9:11 pm Thread Starter
Senior Member
 
Join Date: Jun 2004
Location: Redlands, CA, USA
Posts: 439
Re: Ground Loop Isolator

"Ground loops are very common on motorcycle intercom installations, but there are indeed other types of noise that can plague these systems. We have been trying to figure out which type of noise we are dealing with here (which is not so easy via the forum)."

The noise that I'm getting is an alternator whine and some ignition noise. It was very loud even unbearable when I first started using earbuds. I put an inline GLI that plugged into the earbud cable. It made a significant improvement but did not clear up all the noise. I'm trying to figure out how to get rid of all the noise if possible.

It seems that I really don't have a ground loop problem since it not a loud buzz. However, the GLI did improve the situation. The next step is to bring the grounds back to the battery. Sorry Joe. Guess you don't have to read this thread anymore since it bothers you to hear this. It's good advice and I'm going to try it.

I will gladly take any other advice from those that have experienced this PITA. Thanks
BEhrler is offline  
post #24 of 24 Old Aug 31st, 2008, 9:42 pm
Senior Member
 
dougholck's Avatar
 
Join Date: Jun 2003
Location: Lodi, CA, USA
Posts: 2,423
Re: Ground Loop Isolator

This guys isolated power supply eliminated 90% of the alternator whine from my Bahre unit on my GS ADV.

http://www.davidnavone.com/cart.asp?24&cat=2

Good Luck

Doug Holck
Lodi, Ca

I don't always ride motorcycles,
but when I do I prefer BMW's.
Ride safely my friends

3 Continents -10 Countries - 50 States

02 K1200LTe
04 1150GS Adventure
08 Suzuki DR650
CCR 05, 06, 07, 08, 09, 10, 11, 12, 13, 14
See you 2015 in Coeur d' Alene, Idaho

BMW MOA 109760
AMA Charter Life Member 518333
International Fellowship of Motorcycling Rotarians
HDDC POSSE

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
dougholck is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the BMW Luxury Touring Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Ground Loop Isolation help bigbear Intercom, CB, & 2-Way Radios 15 Jul 16th, 2009 10:13 am
Ground Loop Isolator? GBaker Intercom, CB, & 2-Way Radios 1 Jul 16th, 2009 10:01 am
Ground Loop information overload BecketMa K1200LT 0 Jun 18th, 2007 7:58 pm
iWay 500c audio problem was GPS 11 Apr 26th, 2007 9:07 pm
Garmin 2610 and ground loop isolator rando GPS 2 Jan 4th, 2007 11:22 am

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome