Weird Sena 20S Noise Issue

[Uncle Phil]

Well, here's one for the group - I've got all 4 ST1100s with a 3.5 MM extension plugged into the Ampliriders and run out through the handlebars to plug the Sena MP3 cord into. All 4 have been working great with incredible sound quality and I am very pleased. Today I don't know if there was an eclipse, a full moon or what, but on one of the bikes (Frost) I am now getting strange background noises over the headset. I can go to either 3 of the other bikes with the same headset cords, helmet and Sena and it works just fine and clear. (I do have an 'extension' on the Sena cord to keep from stressing it.) If there is an 'extension' between the Sena and the Amplirider I get the noise (more like attenuation) - the same extension that I can use on the other 3 ST1100s without a problem. I have swapped the Amplirider and the extensions and the Sena (not the base) with no joy. Any ideas?

 

[dduelin]

Is the noise somewhat like a snare drum being struck rhythmically or a popping, snapping, kind of noise?

 

[Uncle Phil]

Kind of like a radio that can't lock into a station. Almost as if it is searching for an FM station.

 

[RaYzerman]

Sounds like perhaps an issue with the jack in the device you are plugging into, I'm assuming you're using a stereo cord and the contact bar inside may not be as snug as the other three. Any way to take the cover off that Amplirider and see if you can "fix it" a little snugger contact?

 

[Diggers1300]

Sounds like a oxidation build up on the connections on Frost. I had something very similar happen with an mp3 player. I buffed the contacts (taking it apart obviously) and the cord contacts. Then coated with an anti- corrosion compound. Did the trick.

 

[ST1100Y]

Do all consumers join the same power and ground connectors?
Possible a ground loop caused by unintended potential between components, could be oxidation related...

 

[Uncle Phil]

Sounds like perhaps an issue with the jack in the device you are plugging into, I'm assuming you're using a stereo cord and the contact bar inside may not be as snug as the other three. Any way to take the cover off that Amplirider and see if you can "fix it" a little snugger contact?

As I said, I already swapped the Ampliriders and the problem was still there.

 

[Uncle Phil]

Sounds like a oxidation build up on the connections on Frost. I had something very similar happen with an mp3 player. I buffed the contacts (taking it apart obviously) and the cord contacts. Then coated with an anti- corrosion compound. Did the trick.

No oxidation unless there would be some on brand new cables.
The strange thing is if I plugged the Sena MP3 cord directly into the Amplirider it is fine.
If I used any type of 'extension' (and I have many and have tried many) the noise problem is there.
I can use 'extensions' off the other working bikes and still get the noise though it is not there on the other ST1100s.

 

[Diggers1300]

If you rotate the plug while it is plugged in, can you hear a change in the noise?
Are all connections gold plated or are they mixed?
Oxidation may not necessarily be visible. If the noise changes, I still say buff all connections, then coat them. That's what my trouble was.
Also, mixing gold vs tin plated can cause problems with noise but that usually happens over time not right away with new connections.

Only other thing I can think of is that a stray rf signal is being generated somewhere on the offending bike. Is it possible to take a complete setup that is working on another bike and try it on that bike?

 

[Andrew Shadow]

Is the noise present with the engine turned off, or only when the engine is running?
If it is only with the engine running, it would seem to indicate something in the bike's electrical system is causing interference as opposed to something wrong with your communications set-up.

 

[Uncle Phil]

Already 'rotated' all the bits and pieces from a known good working setup.
The noise is represent when the key is on and whether the engine is running or not.

 

[Uncle Phil]

The noise went away when I swapped out some audio cables (there are a couple in the mix).
And fortunately it has stayed away and for that I am thankful.