Van DAB radio question

Basically it affects the radiation resonances...RF, as you well know, is tricky black magic. Probably hanging a ferrite slug on the USB cable would change everything

To kill the DAB in the car I just turn on the heated rear windscreen.

But putting a DC charge on a head torch using a USB socket in the van is taking the piss.

A recognised phenomenon.

Eg.

That article is where you simply plug the phone into a charger. I to have an issue with one vehicle where the charge cable routing can vary the interference on VHF radio. Where the charger is built to work for a price and not to conform to any standard.

DAB uses the old band III TV spectrum, 174-230MHz. USB High-Speed uses a transmission rate of 480Mb/s and must produce a lot of random noise according to the data and encoding.

The other aspect of DAB is that performance with signal strength is not progressive like FM radio. As the signal strength falls of there will be a near brick wall where the error rate is such the data cannot be recovered.

What's the FM performance like when the phone is plugged in?

Can you check to see if the phone can charge USB with USB coms turned off and just accept standard charging?

Use an alternative cigarette lighter charger?

You can get "secure" charging only cable that doesn't have the data connection.

You can also buy adapters for your existing cables.

Sorry, sorry, sorry...

...but every time I see this subject title I think the content is going to be about post-impressionist Dutch painting.

Sorry.

Nick

That also suffers. but not as badly.

Would that mean I don't have access to Google maps on the dash? I'll have a mess when I get the van back.

I do. But it's not one I can reach when driving. That still causes some problems but no where as bad as the dedicated USB port on the dash.

It isn’t a Ducato by any chance, specifically a X250 or 290?

I ask as, some of these originally have the radio antenna in one of the door mirrors ( I think the driver’s one). Besides not being the best of antennas, it isn’t unknown for mirrors to be replaced for ones without the antenna and another antenna added. Typically, the mirrors off Boxers don’t have antennas and Boxers have an antenna on the roof, above the windscreen. Ducatos often have a blanking plug here as they use the same body shell.

I understand the correct antenna has a powered amplifier but I’m not 100% sure.

Antenna problems are common on some Ducato based motorhomes. The companies buy in ‘special’ basic base vehicles and add inferior antennas.

I’m on my third Ducato based MH. The first one had a terrible antenna. Second was fine. Current one, bought in March, has a door mirror one, and is fine.

If it is a Ducato and you conclude you have the ‘wrong’ mirror, be aware the mirror also includes a temperature sensor. This is more than for a dashboard display, it is used by the ECU etc. A bad or missing one causes all kinds of issues. It is a little ‘bump’ under the driver’s mirror, about 10mm in dia if that.

There are after market mirrors available, including with all the right bits, but there are numerous versions ( heated, unheated, remote, manual, with/ without antenna, two types ( at least) of indicator, ……. Plus, length short, med, long arms.

Most radio stations have an online presence where you can stream the channel. I use BBC Sounds and stream to my radio, though mine is a little outdated and go the Bluetooth route.

Van Gogh Family Tree

The Family Tree of Vincent Van Gogh (Gogh pronounced go not goff)

His dizzy aunt ................................ Verti Gogh The brother who ate prunes .................... Gotta Gogh The brother who worked at a convenience store . Stop N Gogh The grandfather from Yugoslavia ............... U Gogh His magician uncle ............................ Where-diddy Gogh His Mexican cousin ............................ A Mee Gogh The Mexican cousin's American half-brother .... Gring Gogh The nephew who drove a stage coach ............ Wells-far Gogh The constipated uncle ......................... Can't Gogh The ballroom dancing aunt ..................... Tang Gogh The bird lover uncle .......................... Flamin Gogh The fruit-loving cousin ....................... Man Gogh An aunt who taught positive thinking .......... Way-to-Gogh The little bouncy nephew ...................... Po Gogh A sister who loved disco ...................... Go Gogh The niece who travels the country in an RV .... Winnie Bay Gogh

The uncle who dominates every party ........... Big E Gogh The cousin who studies maths .................. Al Gogh Rythm The future administrator ...................... Mun Gogh The musical nephew ............................ Bon Gogh The sister who never married .................. Vir Gogh

I saw you smiling . . . there ya Gogh!

Don't forget his mum, Ma gogh

Not being French, his name wasn't pronounced like that - but still...

isn't it a sort of clearing of the throat 'hoough'

"The most accurate pronunciation for Van Gogh, according to Dutch speakers, is "vahn KHOKH" with a guttural "kh" sound at the end. "

It's almost like no one uses it, and we know that isn't true. We have people saying "it's just as good as FM" while it runs on a multiplex at 32kbit/sec :-/

So as an experimenter, I would start with:

Your current antenna (rubber duck) is an omnidirectional, but is an unbalanced antenna and uses chassis ground as the ground plane for reception.

They make a "balanced T" for vehicle mount, but a "balanced T" and a TV rabbit ears, while not using the van as a ground plane, they are directional antennas, which means the radio station is going to wink out, every time you go round a turn in the road. I'm not even sure the balanced T available, is for the right frequency range, as the elements look too short for VHF high. (The arms of the T have adhesive for sticking to glass.)

You can combine the output of antennas. In the case of DAB, they make it sound like the receiver can distinguish and suppress multipath.

But as long as there is so little info of a technical nature in Google, who knows what a "proper" solution looks like. DAB is like witchcraft.

Somehow you have to get the chassis metals, out of the equation. A different antenna type might do it. But the directionality requirement, makes most antenna types non-starters. A YAGI would give excellent gain, but at the expense of "only working once in a while" as you drive. You could put a YAGI on a computer controlled rotator, that maintains a particular compass point as you drive, for an example of how that could be fixed. But a mount on the top of a van, that's going to be a significant mechanical load on the antenna (wind resistance).

Good luck, Mr.Science :-) Think of the Nobel Prize for Peace you could win.

Paul

Just a bit of bit reduction!..

A car roof is a very good reception environment consider that its not indoors! also the quarter wave whip on a ground plane is a pretty decent and practical receive aerial. OK in Adams case the van aerial surrounded by ladders and the like won't help much as will aerials inbuilt into the glass rear window but that is almost al that you can do in practice. A radio ham can or will have a much longer aerial that covers more than the one band but for most all users thats not practical as is a Yagi array!.

There is or was a BBC white paper WHP-195 comes to mind that was mainly the effect of small power line IP LAN links that can upset DAB radio.

Its a bit insidious DAB in that with FM you can usually hear interference but that just causes "bubbling mud" and dropout/s on DAB.

However the BBC and the main commercial multiples are now well established as regards coverage but even so that may be areas where insufficient signal does cause reception issues and sometimes they might add in a small filler station if its really unusable.

I am involved in some small scale DAB MUX's using the AAC HE coder or DAB Plus, pretty good results can be obtained at 40 K/Bits for general radio use.

As to the DAB-v-FM debate i was talking the service dept of a very well known Hi-fi firm they get a glut of FM tuners in for repair before the BBC Prom concert season starts, the owners much prefer the sound of FM!..