DAB+ reception interference

[AK83]

Hi all,
Just after I got my D1 mid last year, I immediately removed the crappy old radio cassette and installed a Pioneer DAB+ capable radio.
good unit, came with a steering mounted remote and a Pioneer AN-1(or whatever model) powered DAB glass mount aerial.

Installed it and it worked well enough.
Originally, DAB reception was sometimes hit and miss.
I kind'a worked out that when it rained, or if it was very windy, I'd lost reception in some places.
In my driveway, if I moved the car a meter or two, I lose or acquire reception.

Over the months it seemed to get worse(intermittent reception), and I wasn't all that happy with this DAB system.
I've previously used DAB radio in my old workplace in two of the new trucks. In a word .. brilliant.(trucks were Isuzus).
They never really lost reception, except in one location where there are traffic lights under some HT transmission power lines.
Awesome system, great audio quality, nice features.
ps. I'm not really interested in music as such, more of an ABC talk back listener too .. so iPods and streaming music is not my thing.

Anyhow, back to the anomaly of the intermittent reception I'm getting.
A couple of months ago, I got myself a wireless phone charging setup.
Consists of a wireless charge receiver(on the phone), and a cradle to hold the phone that is the charge station.
I have two charge stations at home, and I also got a suction holder charger doodad for the car.
Basically, you stick your phone on the holder, and not only does it hold the phone,it charges it(slowly) too.
No wires to the phone, I can neatly tuck the wires to the charger/holder nicely too.

BUT!! I just noticed yesterday that I had good DAB reception in my drive as I started the D1, but then as soon as I stuck the phone to the holder, DAB reception stopped.
There's a signal strength meter indicator on the radio to show signal(like a mobile phone).
I know that the DAB system has a little bit of buffering for when reception is iffy, so that you don't lose sound unless reception is lost for a short time.
On most DAB radios I've now experienced, it seems to be about 2-3sec of buffering, as there is always a 2-3 sec delay or time difference between analogue and DAB.
if you switch from analogue to DAB, you hear the last couple of secs that you just heard on analogue.

So, now I noticed that when I pop my phone on the holder and it starts charging, in about 2 sec I lose DAB reception.
I initially thought it may be the proximity of the phone to the radio(about 10cm), but after a bit of mucking about it's not proximity.
it's the wireless charging interference.
No matter where I place the holder charger, driver side door, rear door/cargo area .. etc .. as soon as the charger starts charging the phone DAB reception is lost(zero bars on the signal meter on the radio).

The Pioneer AN-DAB1 antenna is (apparently) powered.
I installed it myself, being very careful to do it as per instructions.
I may have stuffed something, but I'm 99.9% sure I didn't.
I scratched out some paint for it's earthing point and cleaned it good and proper before sticking the earthing pad to the body(interior). glass clean etc, etc ...

So the only thing I can think of as to why the wireless phone charger is causing DAB reception loss, is some kind of active/earthing interference or something.
I also wanted to eliminate the Cheap Chinese generic product syndrome from the equation, so I also tried using one of the chargers I have in the house too, a better quality (supposedly)Samsung holder, but I get the same thing.
it seems that whatever RF interference the wireless charger is radiating, sucks the life out of the fairly weak DAB signal!
Analogue radio is fine(but analogue is so last century now! :p)

In the next few days(if I get the chance) I'm going to install my new Mobile One DAB antenna and eliminate the Pioneer glass mount AN-DAB1 from the equation.
I got the ground independent SAN206 model and will to try to mount it to the bullbar.

ps. Big shout out to Mobile One too. Awesome service from them.
I ordered it on Monday night, but it didn't appear to go through.
Their ordering system is a little different to what is the norm.
Anyhow, I emailed Tuesday night to confirm my order.
Got a reply, saying with an apology for the ordering webpage, but that my antenna was just made up and will be sent out that day.
Got it a Wed arvo. And it is of a very high quality finish too.

Just have to locate an SMA to SMB adapter to connect to the radio too.
Hopefully this new antenna helps in some way, but more importantly hoping for better DAB coverage further out.

Hopefully this info helps anyone else with DAB reception issues.
ie. it's probably some interference from something obscure.

And hoping that someone with good knowledge of RF interference issues can understand why such a low powered device like a wireless charging system(USB @ ~0.5Amp) can kill what I'd assume to be a much stronger(radio) signal?

sorry for the long post,
Cheers,
Arthur.

[Disco4Dave]

The wireless charging RF field will be much stronger that the DAB broadcast signal. The charger may produce a much lower power output than the DAB radio transmitter, but it is also much much closer, and RF signal strength decreases by the square of the distance.
I suspect the DAB receiver has a fairly broadband front end, which is being swamped by the charger RF field.
There are really only 3 solutions:
- Get a stronger signal to the DAB receiver, ie the external DAB antenna you plan to try,
- Find a DAB receiver with better RF filtering, or
- Switch to wired charging of your phone.

[AK83]

Thanks for your reply Dave.

Took a bit of mucking about to get the Mobile One antenna mounted and connected.
Bullbar only had one mount lug for antenna, so I had to weld one on.
So, had to go shopping to get a welder(got a cheapie MIG), and then find a small piece of solid enough steel(good 'ol Robot Trading!!).

Then all the mucking about trying to feed wires through crevices that barely exist .. etc.

Anyhow, all done and works a treat now.

But, I think I worked out why I was getting interference on the DAB signal ...
See pic below:

https://www.aulro.com/afvb/images/imported/2017/02/679.jpg

Errr ... "Houston, we have a problem!"
I must have pulled on a wire that pulled on the antenna coax.
I haven't moved the radio at all since installing the Pioneer AN-DAB1 antenna.
And as I was trying to remove the radio today, it may(must!) have stretched and pulled at the sheath even more.
Any wonder I was getting reception at all, considering it was wedged between a couple of metal plates like that.

I just need to find the time to go for a bit of a drive and check the DAB reception now with the new Mobile One aerial.

[Homestar]

Haven't had my luck with DAB either fixed or mobile. I bought a quite decent radio for the garage, but had to have it outside for it to work, so gave it to SWMBO for work, but it didn't work there either in a concrete Commersial building. It wasn't just our radio either, 2 other bought them in, and despite there being floor to ceiling windows in every office, they just didn't work.

My Boss lashed out and put one in his work car but that's a disaster too, although your tips may help with that one.

Oh, and I'm talking not working within 10KM of the CBD in Melbourne here, not remote or rural.

Unsurprising the uptake of digital radio in Aus has been very poor, it's just too big a Country to make it work effectively.

Bloody pity really as its great when it works - kind of like a Land Rover... ;)

[AK83]

Not good to hear your experiences ...


....
Bloody pity really as its great when it works - kind of like a Land Rover... ;)

For sure.

When I first put mine(actually after I installed the DAB antenna) in the D1, I went for a drive to Ballarat, and had reception all the way up until Kryal Castle.
Just over the hill(there) and down again(at the 2 servos there) is where I lost reception.
Had good reception of ABC Melb(774) all the way.
That was a nice day, sunshine and about 18-ish degrees.

But I found that if it was raining or very windy, I'd get choppy reception.

The other thing I did was to install the DAB aerial in the (LHS) skylight window, not the front windscreen.
The only reason for that was I didn't want to have to install it again, if I ever had to replace windscreen, rather than any technical reason.
Much less likely to get chips and sandblasted skylight.
There was more than enough coax cable to get from skylight to radio, and when I pulled the coax from the stripped part back to the passengers side pillar, there was still plenty of slack there.
So no idea why it got caught up in the metal frames the way it did.

Strangely tho, when I connected the ripped coax to the radio, it still had decent reception on DAB, only when phone wirelessly charging did it drop out.
I'm in Coburg, so pretty decent line of sight to the big smoke and only about 10 klms as the crow flies too.

[SBD4]

Strangely tho, when I connected the ripped coax to the radio, it still had decent reception on DAB, only when phone wirelessly charging did it drop out.

That's because the shielding is the part that was damaged. Without the shielding, the interference was able to get through to the antenna signal and disrupt it. Likely your existing glass mounted antenna would have been fine if you replaced that cable.

[AK83]

... Likely your existing glass mounted antenna would have been fine if you replaced that cable.

That's what I thought too.
But cable is fixed to the Pioneer antenna module, so an entire replacement would be required.