Autocom Noise Question

[Albert]

We took a trip this weekend and discovered a noise in the headsets after using the Autocom for a while.

 

Here's the background: the unit is an Active duo, bike powered. I have the Autocom mounted in the tail section of the RT. I have a bike powered Garmin 2820 connected via an Autocom isolation connector (1285 I think). I also had my cell phone connected and an iPod (neither bike powered).

 

The connections were Garmin = aux 3 (via isolator), cell phone = aux1 and Ipod = aux 2. My head set is the Autocom speakers while my wife uses ear buds (via the Autocom connector) with no speakers attached.

 

On day one all worked fine for 3 or 4 hours. At that point we decided to listen to some music so I turned on the Ipod. After listening for a little while my wife mentioned a "clicking" sound in her head set. After slowing down I too could hear this in my ear speakers. The sound is not really a click but a low frequency "bup bup bup bup bup . . . ". The frequency is not tied at all to engine rpm or bike speed.

 

The same thing happend on the third day but we weren't listening to music, just the communication and gps voice prompts. Disconnecting the passenger cleared up the sound for me both times.

The weekend was quite hot with temps in the mid 90's. I'm wondering if the unit could be overheating? Could the earphones my wife is using be of an impedance that is causing the Autocom to overload? Any thoughts appreciated.

 

[Penforhire]

Bumping, because I get the same low-frequency popping most of the time my Kenwood GMRS radio is turned on. I'm completely battery powered. Curious if we have the same issue.

[Albert]

One thing I've never noticed is the problem showing up when I'm connected by myself. This is what makes me suspicious that it has something to do with the pillion hook up. Since it's not related to engine speed it really has me baffled.

[Tom B]

Al

 

I don’t think the problem is in anyway related to the Kenwood problem as the Kenwood has a power save mode that produces a slight popping noise during power save mode.

 

I agree with you that the problem you have seems to be related to the passenger headset when plugged in using the in-ear-speaker-plugs?

 

How have you connected the passenger speaker-plugs?

 

If using part 1187 or 1188 (headset extension lead with in-line box with 3.5mm socket for in-ear-speaker-plugs) this should be all OK, as the load on the Autocom amps will be low and so not over-heating the amps. However if you have a short somewhere in the headset or headset leads the amps could be over heating and causing the noise?

 

Check the passenger headset lead from the main unit is not trapped/ crushed/ damaged, also check the headset extension lead and the headset down lead for any signs of damage.

 

If you have any friends locally and can go for a ride with them and their headset to test all is well it will again point to the passenger headset/lead. So we may need this posting back for inspection test.

 

Autocom UK Tom

 

[Albert]

Thanks Tom. Yes I'm using the Autocom coiled cord adapters with 3.5mm receptacle in the small box (although I can't recall the part number). When I set them up I cut the speaker connection, so I could have created a problem there (an intermittent short). That will be my first check. Next time we get the chance we'll carry a second set of headphones to switch out as well in case that's the culprit.

 

I'll post whatever I find. Thanks again.