Are Halfrauds winding me up?? Poor DAB signal: powered aerials, LED bulbs and Dash Cams

[Dav-Tec]

I wou

I haven’t, but may shoot them an email now you’ve mentioned it.

I would ask some questions. I usually fit these and not had a problem with Interference with the DAB aerial. I had a cheap set on my caddy and turning lights on and off literally caused dab signal to go on and off

 

[GavMc P11GT]

Interesting!!! Came out of the house this morning to find the dash cam dangling as the adhesive had given away! I didn’t have time to fart on with it so disconnected it and put it in the glovebox! Driving about today noticed we have DAB back in mint condition!

I never considered the dash cam to be the cause of all of this! And by chance the solution literally dropped into my lap!

Now I don’t want to be without a dashcam and this wasn’t the cheapest of models it’s a hardwired Kenwood! But it’s obviously causing interference anyone heard of this happening? I’d have thought a Kenwood would work seemlessly but obviously not!

The wiring goes directly to the fuse box but unlike most cams I’ve had this has permanent live and a ignition live both piggy backed from the fuses the earth is bolted to the metalwork next to the fuse box.


Any help on this would be greatly appreciated!!

 

[Doulsy]

intersting post, i have a line down the middle my windscreen and google says its my DAB ariel, it was pretty poor, but since i fitted dmx9720 reception has been good,(although i have not drove my van that much) just wondering if the kit for fitting from @Absolut5 had something in it for better reception or maybe im imagining it.

 

[Absolut5]

If it’s a Older T5 then line is the fm, later T5s, T6 and 6.1s the aerials are in the mirrors,

Many windscreen companies install old style screens to newer transporters …. It’s certainly not dab

 

[Doulsy]

If it’s a Older T5 then line is the fm, later T5s, T6 and 6.1s the aerials are in the mirrors,

Many windscreen companies install old style screens to newer transporters …. It’s certainly not dab

its a 2017 t6, there is a line down middle of windscreen, thought it was dab or something to do with rain sensor, shuttle

 

[RedUn]

Interesting!!! Came out of the house this morning to find the dash cam dangling as the adhesive had given away! I didn’t have time to fart on with it so disconnected it and put it in the glovebox! Driving about today noticed we have DAB back in mint condition!

I never considered the dash cam to be the cause of all of this! And by chance the solution literally dropped into my lap!

Now I don’t want to be without a dashcam and this wasn’t the cheapest of models it’s a hardwired Kenwood! But it’s obviously causing interference anyone heard of this happening? I’d have thought a Kenwood would work seemlessly but obviously not!

The wiring goes directly to the fuse box but unlike most cams I’ve had this has permanent live and a ignition live both piggy backed from the fuses the earth is bolted to the metalwork next to the fuse box.


Any help on this would be greatly appreciated!!

It's a common occurance, Google it, it's not vw specific!

Supposedly people have had luck fitting ferrite cores to remove the interference.

 

[Doulsy]

If it’s a Older T5 then line is the fm, later T5s, T6 and 6.1s the aerials are in the mirrors,

Many windscreen companies install old style screens to newer transporters …. It’s certainly not dab

sorry just read your reply again, so it could be an old window, my screen ices up on the inside so this cold make sense, rest of my windows are fine, is it possible to retro fit a heated front screen?

 

[Dav-Tec]

Never considered the ferrite core for this purpose don't know why. I do have some of any one wants some mailing and trying

 

[Absolut5]

its a 2017 t6, there is a line down middle of windscreen, thought it was dab or something to do with rain sensor, shuttle

Dab is part of the fm aerial in the drivers mirror

 

[GavMc P11GT]

Never considered the ferrite core for this purpose don't know why. I do have some of any one wants some mailing and trying

I’ll take you up on that mate I’ll give it a try! Plugged the cam back in a the signal was mullered!!

 

[Dav-Tec]

I’ll take you up on that mate I’ll give it a try! Plugged the cam back in an the signal was mullered!!

Inbox me your details mate

 

[Goldy]

I’ve recently fitted LED headlights and taillights. Ever since, my reception is absolutely shocking. It was ok before. Stations I used to listen to are now very patchy at best. What options do I have? I have a heated screen so would it be a fin? Thanks

Mines the same just fitted a new head unit, I've got the THQ LED's when you turn them on the reception is very poor. I've just ordered a bee sting aerial to try.

 

[roadtripper]

Mines the same just fitted a new head unit, I've got the THQ LED's when you turn them on the reception is very poor. I've just ordered a bee sting aerial to try.

The problem is the electrical noise generated by the led drivers (or dash cam processor) being "louder" than the more distant DAB/FM signal. Essentially have a DAB/FM noise generator attached to your van

If you fit an antenna that has more gain you'll just get more of both and I doubt it will help. Relocating the antenna may help.

Ideally cure the source of the noise.

The reason this happens is that LEDs tend to be driven by PWM signals and dashcam processors have a clock signal. Both of these use a square waveform. Mathematically a square waveform is made up of a series of different frequency harmonics. The upshot is any unshielded wire with a high frequency square waveform signal on will be radiating a great number of harmonics, some of which may fall into the frequency bands of FM/DAB

The reason ferrite cores work is that the high frequency signals induce a current in them and the back EMF of that current opposes the original current. Essentially putting a ferrite core around a wire blocks or strongly reduces high frequency signals, which is why sometimes they are called a choke.

To be effective they need to be placed correctly. The issue is high frequency signals bleeding out of electronics on to the cables supplying it power, those cables then act as antenna to radiate the signal. To be effective you have to block the signal as close to the source so the length of wire it is on has the least chance of radiating it. So you should place them as close to the noise generator as possible, which is why you commonly see them moulded into camera and laptop leads just behind the power connector.