How can I eliminate Ground Loop Interference?

Bumpkin

Formerly VFRChas
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#1
I have recently changed from using an Autocom to using a a Sena Bluetooth headset and also a Sena SR10. The latter is a hub that connects via Bluetooth to your headset and can also interface with a PMR radio and press to talk switch.

The SR10 works well but exhibits Ground Loop Interference when powered off of the bike. The PMR radio is also bike powered, hence the ground loop. Unplug the 12v to USB converter that I've wired in to power the SR10, so it's running off its internal batteries, and no interference.

Would adding an isolated DC-DC converter such as this , to the 12v side of the USB converter help to eliminate the GLI. Any electrical engineers care to comment or suggest a solution.
 

JZH

VFR Club Bodger
#3
You can try a power-side isolator--it's easy and cheap enough for a punt--but I think there is a reason why Autocom went with isolating the audio side. Can't recall what that reason is, though! The audio ones are also available on eBay for not much.

Ciao,
 

Bumpkin

Formerly VFRChas
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#4
Thanks guys. Yes the filtering on the audio side as per Autocom would probably work best. However, the cable from radio to the Bluetooth SR10 hub is very spindly. trying to solder a filter into that is going to be difficult if it's even possible.

I don't think that the ferrite ring type suppressors work for GLI, I could be wrong.

Have ordered a couple of the isolated DC-DC converters that I linked to, will take a while from China though I did received notification today that they had shipped via airmail.

Might all be a moot point in a month or two as a change of bike might mean PMR radio and SR10 will be living in my tank bag, and only when required, rather than being permanently installed under my seat.

Today I test rode this


A few weeks ago this


Thought I would ride the MV purely out of curiosity, got to say I was very impressed on quite a few levels, I did even use the word 'smitten' as Pete/48, who was there, will attest.

Now got to go back for a proper test ride on the Multistrada as the first one was a disaster (accompanied ride that didn't get out of third or above 50mph despite empty NSL roads). Complained and was told I could come back for a more spirited, but still accompanied test. Couldn't have been further from this today, Ed Cosker chucked me the keys at 10:30 and said take as long as you like, we close at 5pm. Covered 100 miles stopped for lunch and got back at 4pm to chat about options etc. Local dealer and very nice ride for me to get there...
 

PAD

Registered User
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#5
Very nice indeed! I'll be interested to hear how you think the MV and the Ducati compare.

I threw in the ferrite job because it's being advertised specifically for use in tackling GLI. I have a couple of different sized ones somewhere. If you're not in a tearing hurry, I could dig them out and bring them on the Shires ride on the 23rd. Or post them to you. I have my doubts, but it's worth a shot for free!
 

PAD

Registered User
Site Sponsor
#7
Prevention being better than cure, eh! But I guess it can be a bit difficult to achieve, depending on where items are installed, without having to route miles of wiring around the bike? Somehow, I can't imagine Chas not having taken care of stuff like that though, fastidious kind of chap that he is!

I have all my accessories supplied via a PDM60 module and that does provide a very good common earth (amongst other things) and everything is beautifully interference free. That's a bit OTT price wise for solving such a problem, but I guess Centech, Fuseblock and other such panels would achieve similar at less cost?
 

Bumpkin

Formerly VFRChas
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#8
Very nice indeed! I'll be interested to hear how you think the MV and the Ducati compare.
Need to go back for 2nd test ride, a proper one this timw, on the Multistrada to be sure. MV is smaller and lighter, more revvy and eager (given different configurations not surprising). Whilst the Multi would probably make a more relaxing tourer and has considerably more grunt the MV is more fun, not too behind on the touring front and just oozes quality... I really, really want one. Trouble is the financial woes back at the factory and ensuing new bike supply issues. Once the former is resolved I might have to pounce or wait until next year.

PAD said:
I threw in the ferrite job because it's being advertised specifically for use in tackling GLI. I have a couple of different sized ones somewhere. If you're not in a tearing hurry, I could dig them out and bring them on the Shires ride on the 23rd. Or post them to you. I have my doubts, but it's worth a shot for free!
Thanks PAD certainly willing to give it a try. Not sure if there will be any with radio on the Shires run though.

50th VFR said:
Good practice is to earth all items to a single common earth point.
All items wired into one of Finks looms so, yes, a common earth.

PAD said:
I can't imagine Chas not having taken care of stuff like that though, fastidious kind of chap that he is!
:} :rolleyes:

Change to new bike will mean that affected items will both be running on battery power in a tank bag and thus GLI won't be an issue. The MV has no under seat storage to speak of. Just as well as you need tools to get the seat off.
 

Pete/48

Registered User
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#10
Need to go back for 2nd test ride, a proper one this timw, on the Multistrada to be sure. MV is smaller and lighter, more revvy and eager (given different configurations not surprising). Whilst the Multi would probably make a more relaxing tourer and has considerably more grunt the MV is more fun, not too behind on the touring front and just oozes quality... I really, really want one.
Is there any wonder that I don't find that hard to believe after seeing your face after we stopped for the first time whilst on the test ride :),
I can only think that the look on your face was similar to that of a five year old kid who had been given a bucket full of Smarties for breakfast, the total look of sheer wonder and disbelief ;),
The handling must have been pretty darn good also, as I know I'm not the fastest rider out there by any means, but I'd also like to think I'm not the slowest either, but mostly the only time I got to see you was when you'd stopped at junctions waiting for me to catch up :}, and then you were off again like the proverbial scolded cat, (i-e the proverbial scolded Cheshire cat, complete with that massive grin on your face) :burnout::rolleyes:,

So all I can say is , YES I'm sure he had an enjoyable day testing that MV,:d::d:,

PS, As I did, just trying to keep sight of him for some of the time during the near 100 mile test ride :rolleyes:

---Pete,
 

Bumpkin

Formerly VFRChas
Site Sponsor
#11
Chas, before you pull the trigger I urge you to try a KTM1290 Super Adventure - even if only to rule it out ;)
Sorry Jim, I don't mean to sound rude or disrespectful of your choice of bike but I couldn't bring myself to buy such an, IMHO, ugly bike. I know that sounds superficial but in part, for me at least, I bike has to stir my soul on many levels and the KTM falls down on the looks side of things big time.

Beauty is, as they say, in the eye of the beholder so whatever rocks your boat.
 

-Mac

Back in the light
#12
Sorry Jim, I don't mean to sound rude or disrespectful of your choice of bike but I couldn't bring myself to buy such an, IMHO, ugly bike. I know that sounds superficial but in part, for me at least, I bike has to stir my soul on many levels and the KTM falls down on the looks side of things big time.

Beauty is, as they say, in the eye of the beholder so whatever rocks your boat.
Fair enough, Chas. I know some people miss out on great bikes because they can't get past looks. I'm the reverse and really appreciate function over form.

I'm not saying I'll never go back to Ducati, but having owned a first and second generation MS Skyhook, and seen all the problems with the DVT on the Ducati forums, I think it'll be another generation or two before Audi sort out the reliability problems that would even tempt me to go back (if Audi don't sell Ducati first to pay for the VW debacle, that is).
 

Bumpkin

Formerly VFRChas
Site Sponsor
#13
Fair enough, Chas. I know some people miss out on great bikes because they can't get past looks. I'm the reverse and really appreciate function over form.
Ah but having a great bike and the looks, that's what I'm after :rolleyes:

I'm not saying I'll never go back to Ducati, but having owned a first and second generation MS Skyhook, and seen all the problems with the DVT on the Ducati forums, I think it'll be another generation or two before Audi sort out the reliability problems that would even tempt me to go back (if Audi don't sell Ducati first to pay for the VW debacle, that is).
TBH I've sort of been put off the Multistrada. I can't deny that it's a looker but the general opinion of a significant number of owners, and yes we are talking forum chatter here, one still gets the impression that there are real issues. Added to which quality of finish seems to have fallen victim to the bean counters at Audi.

No doubt if I buy the MV Agusta it'll grenade itself a month out of warranty half way up an Alpine pass :rolleyes: However, having spent a part of today doing further research and chatting to owners, some of which have previously been unhappy MTS owners, I am reassured. Additionally I have also received positive reviews of my local dealer.

I think I should have started a new thread... :blush:
 

PAD

Registered User
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#14
Can someone reasonably be accused of hijacking their own thread?:)

It's a hell of an expensive way to get rid of ground loop interference, all the same!
 
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