Radio Static

[RazzRJB]

Hello,

I'm not an electronics person but I'm desperate for an electronics answer!

I'm working on my motorcycle. It's a 2012 Harley Davidson Electra Glide, which if you're unfamiliar with motorcycles is a full dresser. That means it has a fairing on the front which houses all the electronics such as the radio, speakers, all the gauges, etc. That's just a little background info. leading up to my question.

Here's my problem, I installed a USB port in the lower right hand side of the fairing so I can charge my phone while I'm using the GPS as I sometimes go on very long rides. The problem is that when I plug the phone in to charge it, it completely knocks out my radio. All I get is static unless it's an extremely strong signal. So I thought that OK, I ran the power supply wire down the backbone of the bike which is where the radio antenna wire also runs. That must be causing the problem. I did all this a couple of weeks ago.

So today I pulled all that wiring out and re-ran the power supply wire under the bike and back up into the battery compartment completely away from the antenna wire and the result after working out in the 100° Florida sunshine ... the same damn thing!

All the connections on the radio are good. All the connections that I've made are good. Everything works fine up until I plug my phone in. One thing I did forget to mention is that I'm using one of the new wireless phone chargers. The mini USB actually plugs into the charging cradle and the phone sits in the cradle. But if I'm not mistaken, I also tried plugging directly into the phone.

Can you please tell me what I'm doing wrong or just what I need to do to make it work? I'm really good at fixing things and doing things myself but of course there are some things I simply don't know and apparently this is one of them. Please help me.

 

[Harald Kapp]

The wireless charger's high frequency operation may be the culprit. The frequencies used by the charger may interfere with the radio on your Harley.

First try to insolate the problem:

• Wrap the charger+phone into conductive foil. Copper would be best, but is not that easy to come by. 2 or 3 layers of aluminum foil should be good, too.
  If this helps, the only viable solution I can envision is using a wired charger.
• If this doesn't help, try inserting a power line filter between the motorcycles power and the charger's power input. Put the filter as near as possible to the charger's input.

 

[(*steve*)]

My guess is that you are using a cheap 12v to 5v usb device. These have switchmode dc to dc converters inside. These are, as you've found out, very electrically noisy.

 

[Harald Kapp]

My guess is that you are using a cheap 12v to 5v usb device. These have switchmode dc to dc converters inside. These are, as you've found out, very electrically noisy.

Another good idea. You can check this by connecting another USB powered device (note the charger/phone) to the converter. A power line filter can help here, too, or buy a better 1 2V to 5 V converter.