I have poverty spec T4 headlamps on my T6. The old incandescent DRLs look so old fashioned, and I wanted to change to LEDs. The first problem with this is finding reliable CANbus ones that don't bring on the bulb failure monitor. All the ones I tried caused DAB interference. I almost lost interest, then tried a fix with chokes in series with the LED lamp.
A couple of 330uH chokes soldered into the DRL lampholder.
These then siliconed in place to stop them breaking off in time.
Once fitted, all DAB interference gone! All station reception restored. Before this, it was drive with the sidelamps on or in silence.
I tried to get before and after traces on a 'scope. This was ignition on, but engine not running, and using an awesome kit built digital storage scope bought from Ali Express. Before;
Only 200mV, but noisy signal induced on the DC feed. There must be loads of harmonics in that covering the DAB band.
Here's the after;
Still peaks of 80mV, but all the choppy HF noise being stopped by the chokes.
Quite a bit of work just to get a mod working without causing other issues..
A couple of 330uH chokes soldered into the DRL lampholder.
These then siliconed in place to stop them breaking off in time.
Once fitted, all DAB interference gone! All station reception restored. Before this, it was drive with the sidelamps on or in silence.
I tried to get before and after traces on a 'scope. This was ignition on, but engine not running, and using an awesome kit built digital storage scope bought from Ali Express. Before;
Only 200mV, but noisy signal induced on the DC feed. There must be loads of harmonics in that covering the DAB band.
Here's the after;
Still peaks of 80mV, but all the choppy HF noise being stopped by the chokes.
Quite a bit of work just to get a mod working without causing other issues..
