R1100S HID lights radio interference

[Gibson335]

Being a radio ham (G4OIA), I ought to know the answer to this one but posting this to avoid reinventing the wheel if someone out there has come up with a definitive solution: Fitted my cheapo 'Hawk' dipped beam HID lights and I am amazed at how good the result is - probably the best mod I have ever done on a bike - however I normally ride with earbuds connected to a small portable radio in my jacket pocket permanently tuned to R4 and I discover that the signal on FM is completely wiped out by the installation. Buggrit.

Doing some Googling highlights this as a very common problem with HID equipment. I've ordered some clamp-round-the-wire ferrite parasitic filters which won't arrive for a while but wonder if anyone on Boxertrix has experienced the same issue and come up with a magical answer. Because I used heavy duty sticky pads to secure the ballast to the front of the tank, there is no direct earth connection to it (its electrically fully-floating) so that's where I'll start, followed by fixing the ferrites on the input leads to the ballast close by it and also at the pos and neg connections by the headlight nacelle. Don't believe it's RFI - much more likely to be direct pickup from the power leads on what is effectively a broad-band spark-gap transmitter. After that, all I can think of is wrapping the HID harness in its entirety with mesh and grounding it at several points along its length. Any other ideas anyone?

[Gibson335]

I contacted Chris Bartram - a mate of mine who is a professional high-end RF engineer for a steer on this issue: see below

Hi Chris; quick query.  I recently installed a dipped-beam HID light on my motorbike (probably the best mod I've ever done to a bike - amazing difference from the standard halogen), however I normally ride with a small portable FM radio permanently tuned to R4 with audio delivered via earbuds inside my helmet and the HID installation completely wipes out reception.

I've ordered some clamp-round-the-wire ferrite parasitic filters and intend placing them round the ballast input connection wires close by the ballast itself and also at the pos and neg connections in the headlamp nacelle. The ballast itself is stuck to the front of the tank with HD sticky tabs - it's therefore fully floating electrically, so I'll sand off some paint and make a ground connection directly from it to the frame of the bike.  Any other ideas? Googling shows this to be a very common problem, so if you can come up with a dedicated filter...

Hello Si

Good to hear from you.

I suspect that the ballast unit is actually a switched mode power supply, and is probably designed with typical Chinese attention to cost, rather than detail ...

If the designers - or more likely the manufacturers - have omitted some or all of the EMC protection components, the unit will act as a wonderful broadband transmitter. But I don't need to tell you that! Grounding the case will help any residual EMC components do their job, and I suspect that then adding suitable clip-on ferrite sleeves - very close to the ballast unit - will actually clear the problem.

The other way of handling this problem is to use the trading standards route, but that will either require gathering objective evidence yourself, setting-up a group to do so, or having a trading standards department competent to gather the evidence. The latter is pretty unlikely, hence the way in which Chinese manufacturers, and their importers ignore the statutory requirement for good EMC design.

Let me know how you get on.

Cheers

Chris

Will post again when I've got the filters installed.

[Gibson335]

Eventually (took two months) my clip-on ferrite filters turned up from China: once the RH fairing was off, it was a 1-minute job to place them on both power and earth return leads close by the ballast. Now 99% of the radio interference has been removed. If anyone else needs to cure this issue, you require 2 (but buy a pack of 5) 9mm clip-on TDK Ferrite filters. £4.99 for 5 on fleabay - current item number 260881949921. For belt and braces, I used one of the two left over around the wires entering the headlight nacelle, but to be honest that's overkill.

[ianbcr]

I don't have a problem with this, I have hids but don't use a radio while traveling. but its nice to see you have a fix and a great post of how you cured it and shared with the rest of us, well done sir.

[Boxermed69]

What's that - 3 months plus with no Archers?

Glad you got it sorted.

Mike

[Gibson335]

LOL - actually I was reduced to using an MP3 player stuffed with ancient episodes of The Navy Lark, I'm Sorry I'll Read That Again and Round the Horne. It'll be good to have John Humphries back on my morning trips into work...