SR10 Needs Ground-Loop Isolation

Comments

67 comments

  • Joseph Swick
    Joseph Swick

    One thing I failed to mention, was that unless it's an *isolated* power converter, you'll still have a ground loop as the grounds on most dc/dc converters are tied together, as making an isolated power supply is more complicated.  That's why I specifically called out the part from Mouser, as it was one of the few things I could find at a reasonable price that would actually do the correct thing.  It does require a bit more effort to wire things up.

    However, I'm just going to call this out here, the SR10 has some severe design flaws (or firmware bugs) in it that makes it unstable for all day use.  It'll probably be fine for an hour or two (though I've heard them putting out bad audio right on power up).  But, if you want to be able to run it all day (10-12 hours+), it's going to give you problems, whether you power it off the bike or not.

    0
  • Ken Kimari
    Ken Kimari

    I too have experienced the robot/cylon voice experience from time to time. I've found that if you initially double tap the PTT it leaves the connection between the SR10 and headset open continuously and the problem doesn't develop, however you lose some functionality like listening to music in between radio conversations.  Haven't noticed an appreciable difference in battery life as it runs all day in that configuration without problems. 

    1
  • Chris
    Chris
    I have ordered a isolated converter, so looks like that will solve my problem of noise when transmitting on bike power. I have had a Socket wired to a switched source on the bike and then plugged the sena adaptor into that, but never realised I could have just run the direct 12v to the SR10 socket. And it's funny you mention the robot like voice. Just the other day a friend had been out on a run and when transmitted he sounded like a robot! I don't seem to have had that issue yet.
    0
  • Joseph Swick
    Joseph Swick

    When the Borg/Cylon/Robot voice first started happening to me, power cycling my SMH10 headset on my helmet resolved it temporarily, but it always came back.  Which makes me believe it's more of a firmware issue, rather than hardware.  However, the warranty went out on my SR10 right around that time, and my headset was already out of Warranty so Sena wouldn't help me out with it.

    Since then, I did buy a new SR10, but now going to return it because there has been no new firmware updates for the SR10 or SMH10. As I've been around several others who've had the same problem, and have gotten replacement units from Sena with no resolution to the problem.

    0
  • Dave Turner
    Dave Turner

    Hi Guys,

    I have been experimenting with trying to resolve the ground loop problem without spending a fortune.

    We seem to have resolved the issue by using a ferrite ring with 10 turns on both +ve and -ve wires of 12v feed before going to the 12v Sena cigar plug.

    Tested and working on GL1800 Goldwing using BaoFeng UV-5R with 12v adapter on external aerial.

    There is still a bit of an issue with the SR-10 causing the radio to become de-sensed on receive by the bluetooth transmission of the SR-10. This is reducing the range of received transmissions.

    Has anyone else experienced or resolved the de-sensing issue?

     

     

    0
  • Rocket Moto
    Rocket Moto

    Dave, this isn't an issue we've experienced with radios that have a more selective receiver, like Kenwood and iCom. You may try to separate the radio and SR10 by a greater distance, perhaps? Stretch the coiled audio lead to its maximum. Also worth trying is a ferrite on the audio lead at the SR10 and the radio end. Or a better radio :-).

    1
  • Dave Turner
    Dave Turner

    Hi Adam,

    I have used a Kenwood TH-D7 and also Yaesu vx-5r and experience the same issue.

    It does get better with distance but still very noticeable. I will try using ferrite on all leads to see if this helps.

    1

Please sign in to leave a comment.