# Motorhome cab radio - chasing the Holy Grail?



## deefordog (Dec 31, 2013)

I know there's been many threads on this subject both on here and other forums but this is a topic I really want to crack - poor reception.

Let's take our 2008 Kontiki Hi-Line (over cab luton). Assuming I had an aerial in the mirror, I've fitted an external radio aerial on the n/s cab wing AND earthed this back to the chassis. Fitted a new JVC head unit and also fitted an in-line aerial amplifier. Still getting poor FM reception  .

There's one thing I don't subscribe to and that's this ground plane thing. When we had a large fibreglass boat with electronics everywhere, we fitted a car radio and for an aerial we simply used 5m of coiled up 2-core cable connected to the radio via a car radio aerial plug. Fantastic FM & AM reception wherever we travelled and picked up stations we never new existed.

So what's the big deal with trying to get good FM reception in a MH and why do so many owners have issues? Basically, I've run out of ideas but feel there has to be a solution.

Where next guys?


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## fantails (Oct 24, 2013)

Go digital - much better reception. FM is being phased out beginning 2015, and should be complete by 2018. There will be a transition period when the 2 go side by side (a bit like the tv) and then gone. However, if going abroad a bit of an issue as the French have not agreed to the same digital signal .


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## Jimbost (Aug 25, 2012)

The 'ground plain' thing you refer to is very important to both reception and transmission of radio waves. The fact that you had great reception in your boat is because of the very large ground plain it floats in ... water.. . It does not necessary to have a direct connection as putting it simply there is a 'coupling' in a capacitive sense between the water and the grounding of the radio. Because the 'ground plain' is so massive its inherent losses due to capacitive coupling are reduced significantly. The ground plain is what makes a normal car antenna or heated rear window as is used now work. Most car bodies are metal and act as great ground plains.

The ground plain is an important part of most antenna systems and that is what Radio Amateurs and long wave and medium wave radio transmitting stations pay great attention to. Most large commercial long wave and medium wave transmitting systems are larger that the actual transmitting antennas used. You cant see most of the ground plains because they are usually on or just under the surface of the ground. The systems have to be huge because of the wave lengths of the radio waves run into tens or hundreds of meters Except in a boat or ship where it is not such a problem. 

FM transmission and reception is easier to achieve because of the length of the radio waves are that much smaller, hence the smaller antenna's. Where we as motorhome users come unstuck is if the antenna is mounted through fibreglass. if the underneath of the area where the antenna is mounted was covered with a square meter or so of tinfoil and connected to the earth side of the antenna the tinfoil would act as a small ground plain and improve reception. Second best is to connect the antenna earth of ground connection to the chassis of the motorhome with a big (thick) earthing strap. Again this will improve reception. Both are problematical as the tinfoil needs to be fitted during manufacture and the earth strap is not the easiest thing to run through to the chassis. 

Having said this most problems are down to poor connections so the first step would be to ensure all existing antenna and antenna ground connections have a good electrical connection. Occasionally some installations are inherently poor and things need to be improved by changing the cabling to the antenna as some are really not worth being fitted in the first place. Possibly the antenna may not be up to a good standard and may have to be replaced. Radios do 'wear' out and the electronics can get 'damaged' and reduce the sensitivity giving poor reception. 

So if you suspect poor reception of your radio check the connections and antenna are of good quality before rushing out to buy a new radio. One thing.. Increasingly more and more reception booster amplifiers are being fitted in the antenna line these are more likely to fail as they are by there very nature very sensitive and can be damaged by excessive static discharges. Better quality ones are protected against this but everyone builds to a price. To find out if you have one you need to refer to the manufacturer or follow the antenna connection. if you find something that looks a small box or covered in shrink tube in the line that's probably it. It most probably will have a voltage connection too. Some do not as the voltage is fed up the antenna cable by the radio you are unlikely to find this but you might be lucky enough to have a VERY up market radio system fitted.


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## javea (Jun 8, 2007)

Had the same problems as you, tried wiring the radio power from the leisure batteries and this did help.

Mike


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## Agilityman (Aug 17, 2009)

Deefordog,

You don't say what radio you have, but if it's the one originally supplied by the cab manufacturer, like Fiat and Peugeot, then it's probably rubbish in my experience. Suffered for years with bad reception, RDS system not working etc. then bit the bullet and bought a cheap Pioneer car radio - WOW reception was fantastic, RDS worked, received radio in places I had never received radio. Never changed or messed with the aerial at all. It was the crap radio all along, that was my experience.


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## deefordog (Dec 31, 2013)

To date, we've changed the we think is the original Blaupunkt and as we wanted something with a USB connection on the front, it got replaced last week with a JVC head unit.

Have also fitted a new external aerial on the wing and earthed it to a point in the engine bay to make sure of a good earth. Also fitted a separate in-line cheap aerial signal booster (made no difference to the reception) to the aerial lead at the back of the radio. After all this, we're no better off than with the Blaupunkt but we do have a USB port now.

Funnily enough, reception seems to be a tad better before the radio is pushed back into the dash :? . The radio is purely whilst we're going along as we use a 240v Roberts DAB radio when on EHU.

So there we are - what's gone wrong or am I missing the obvious?


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## Jimbost (Aug 25, 2012)

If you reception is worse with the radio pushed further in it is worth checking a few things. It would seem the radio is getting a poor connection somewhere and moving it allowing better connection. 

You will need a multi meter to carry out a proper check. There are many good video's on YouTube that show you how to properly use a multi meter.

First rule of fault finding: is never assume, always every time, check. Just because it is new it does not mean the connection is good. No voltage is being measured so no connections should be made to the pos + at any time. You will be measuring resistance so set the meter to Ohms. Turn of the vehicle ignition and make sure the radio is off. you will usually find three plugs in the back of the radio. Antenna, speakers and power find the negative and a bit of bare metal of the vehicle chassis. Check the negative connection to the chassis it should read 'o' Ohms if you have reading above then the connection is poor and you need to investigate. 

Pull out the antenna connection, check the outer (not the centre) to the chassis. Again it should read '0' if you get a greater reading than that it means that you have a problem with the earthing of the antenna and its cable. NOTE in some cases the outer connection is earthed at the radio and not at the antenna. If you antenna is earthed at the base of the antenna then this will test the effectiveness of the earth at that point. If you are getting a reading of more than a few ohms then the earth at the antenna base is poor or the cable is faulty. Even with a power booster inline you should get a 0 or very low ohm reading. 

If you do not have a multi meter you can just use a bit of wire. The radio will need to be switched on. Bare the ends of a length of insulated wire with enough length to reach the points you need to test. This is an earth test so no voltage will be applied. 

With the radio out and switched on make a connection between the radio chassis and the vehicle chassis. If reception improves the existing connection is poor either on the radio or the antenna. 

This a quick explanation I am happy to explain further if needed. Remember you are working at your own risk, if you do not mix up live and negative you will be ok.


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## deefordog (Dec 31, 2013)

Thanks for the pointers Jinbost. Haven't got round to checking the earths and continuity but here's one thing I have found.

Ignition off, radio on - good reception though it's a bit hit and miss what stations are found on an auto search. Good clarity of sound.

Ignition on, radio on - very poor sound clarity, lots of interference, auto search won't pick up anything. Previous weak stations are now non existent.

Doesn't really get us far as we need the radio most when on the move and not when pitched up with the engine off - damn.

Any ideas Jimbost?


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## Jimbost (Aug 25, 2012)

Greater load on the battery when ignition switched on means a reduction in voltage where a poor connection exists there will be a greater loss. without the engine running and the alternator running to boost the voltage it would show up more This poor connection can be in the positive side or the negative side of the radio or associated connections. It can also mean a poor ground (earth) connection on the battery _*somewhere*_ There are so many possible ground returns on a modern vehicle it can make a poor connection a nightmare to find. You have the main chassis ground connection as generally that's the point where you are likely to suffer a problem. BUT I expect the vehicle is starting ok with no other faults showing? this would point to something more local to the radio supply circuits

First point I would check is the actual voltage being supplied to the radio with the engine switched on and the engine running and then engine off with ignition switched on. Finally check the voltage with the radio on and the ignition off. In all cases you should read the same as at the battery between about 11.5 (nearing discharge) and 13.8 voltage (engine running and float charging) Slightly higher if the battery is receiving a high charge. Most car radio will work quite happily between 10.5 and 15v as an internal regulator in the radio stabilizes the voltage. Again I suspect that you will find the voltages within range.

This leads to another possibility 'stray voltage' Not very easy to explain this one. Within the wiring of any modern vehicle exists a huge amount of wiring and hundreds of connections. Simply its possible for a low voltage potential to exist between two or more earthing (ground) points *IF* poor connections exist. This has the effect of reducing the earth side voltage. The effective supply voltage is reduced by the amount of the potential voltage held on the earth side of the connection. So... if you have say 2v potential on the earth side it will reduce the effective supply voltage by that same amount. 12 - 2 = 10. It can also cause voltages to be sent where they should not causing problems somewhere else.

Fortunately this type of fault is rare but the cure is simple, repair the bad connections. Finding where is the problem.


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## fatbuddha (Aug 7, 2006)

> but if it's the one originally supplied by the cab manufacturer, like Fiat and Peugeot, then it's probably rubbish in my experience. Suffered for years with bad reception, RDS system not working etc. then bit the bullet and bought a cheap Pioneer car radio - WOW reception was fantastic, RDS worked, received radio in places I had never received radio. Never changed or messed with the aerial at all. It was the crap radio all along, that was my experience.


I'm kind of in the same boat with my Fiat based Rollerteam - the radio reception is crap.

I've already had the aerial changed to a better windscreen mounted one by the company who fitted my alarm system (they also fit radios). I also asked them to rig the radio so that it played off the battery without needing the ignition on (who designs these things to work that way??). at the time they did this I said I'd see how the radio got on and although the new aerial has improved matters, I think the radio is such a basic unit that it's never going to get me a decent signal.

so - I'll go down the new radio route but a simple question - is it just a case of swapping new for old and using the same connections?? do these units all follow a standardised setup on the back??

any suggestions on brand?? I was thinking of perhaps including a DAB unit, but that would need an additional aerial as well so I think I'll just stick to a FM/AM/LW/CD unit for the time being - I already have a Pure DAB unit that links to the radio by FM signal so no need to replace that for the time being.


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## Gary1944 (Feb 21, 2009)

My experience is similar although I didn't want to drill holes in bodywork so fitted a windscreen boosted aerial. Slightly better but still pretty poor. Before trying a new radio I had a lead fitted to the TV aerial. Result, great reception, just as good as our car, all I ever wanted. So if you have one fitted (I realise some just have Satellite) then try a lead run loose before routing it through the furniture. All it will cost is a few metres of co-ax and a couple of connectors. Peanuts compared to the other solutions.

Happy listening.

Gary.


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## fatbuddha (Aug 7, 2006)

I don't have TV in the motorhome - and don't plan to - so the radio being connected to a TV aerial is not something I will be able to do.


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## Tintent115 (Dec 20, 2012)

fantails said:


> Go digital - much better reception. FM is being phased out beginning 2015, and should be complete by 2018. There will be a transition period when the 2 go side by side (a bit like the tv) and then gone. However, if going abroad a bit of an issue as the French have not agreed to the same digital signal .


I seem to remember reading that FM radio had a reprieve........???

http://www.telegraph.co.uk/finance/...vernment-abandons-digital-radio-deadline.html


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## deefordog (Dec 31, 2013)

Gary1944 said:


> My experience is similar although I didn't want to drill holes in bodywork so fitted a windscreen boosted aerial. Slightly better but still pretty poor. Before trying a new radio I had a lead fitted to the TV aerial. Result, great reception, just as good as our car, all I ever wanted. So if you have one fitted (I realise some just have Satellite) then try a lead run loose before routing it through the furniture. All it will cost is a few metres of co-ax and a couple of connectors. Peanuts compared to the other solutions.
> 
> Happy listening.
> 
> Gary.


Might be worth a go and connect it to our Status 550 amp as it's got a radio connection which isn't used.

Cheers Gary.


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## Talaris (Aug 19, 2012)

Changed our head unit to a Pioneer DAB unit. 3600 I think is the model. Aerial on the side window which is very discrete. Great reception and a real easy to use unit. Fitted by Vanbitz who did a great job too.


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## Techno100 (May 8, 2010)

DAB aerial is the future. Pictured for a left hand drive vehicle


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## pete4x4 (Dec 20, 2006)

As a general tip, if you do have poor reception check that you dont have a usb charger plugged into your cigarette socket such as a sat nav, they are notoriously bad at causing interference throughout the fm band.

My radio suffers enormously when I have a usb charger charging Iphone and satnav. So worth unpluging anything first.


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## Patrick_Phillips (Aug 17, 2006)

I would be wary of too much reliance on digital for camping.
Not only is the rural coverage rather poor at present - hence the retention of FM indefinitely but...
Digital radios are very very thirsty of battery supply.
It isn't just France that is using a different form of digital radio - in Europe it is the UK that are out of step; again!

Patrick


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## Addie (Aug 5, 2008)

My solution - a powered (from the cab battery) bee-sting aerial mounted on an IP67 box on the roof. Not particularly elegant I might add!









http://www.europebycamper.com/2013/12/roof-mounted-fm-radio-antenna.html


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## deefordog (Dec 31, 2013)

Had a bit of time to spare today so ran a temporary coax cable from the back of the radio to the Status aerial. With the ignition/engine off, picked a weakish station with fairly good clarity and it was about the same as when using the external aerial.

Turned the ignition/engine on and hey presto, still good clarity. So this seems to be my solution as per gary1944 above. Have run the coax down behind the dash, under the cab carpet, up to behind the o/s overhead lockers and around a corner into a cupboard where the Status amp is above the fridge/freezer.

Looks OK but more importantly, there's zero interference from the engine. The proof will be when we're on the move - will let you know how it fairs in the near future.


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## Pudsey_Bear (Sep 25, 2008)

I don't seem to have any reception problems, I have a nondescript JVC I bought yonks ago and never used, it works fine good reception and I can play music from the Smartphone, however as soon as I fire uo the TomTom, the reception goes from quite good to turn that bloody thing off, or play a CD, it really is awful.

Not sure what to do to fix it, the TomTom is hard wired to the LBs via a 3 way cig lighter socket, using a USB adaptor.


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## flyinghigh (Dec 10, 2012)

Radio reception on a A class
Had the A class a year and been very disappointed with the radio reception,
So initially replaced the stuck on screen aerial with a standard roof aerial bolted to the chassis for good ground, about a 20% improvement but still well below what I consider as acceptable,
So round two, I ran all my feeds and earths from the leisure batteries using good quality chokes and fitted a second aerial in the O/S wing both feeding the radio through a splitter, another 20% improvement followed but still not satisfied!
Round three, as the radio had come already fitted and though a good brand name (Sony) I decided to replace it with the latest DAB Sony CDX700U radio
Again the DAB aerial being a screen stick on type, 

now we seemed to getting some where at long last! 

The DAB side work much better than the FM and on long runs I could have probably lived with it, but as the wife said I am like a dog with a bone so this weekend decided to give it my all,

First purchased a top quality Kinetic DRA-6004 roof aerial, two rolls of copper adhesive tape, up on the roof drilled down into the wardrobe and fit the aerial,
That's the easy part,

Now my roof is composite construction with fibreglass top with a core of foam finished off inside with plywood covered material,

Now because the roof material is non conductive it is useless as a ground plane for a aerial, IE it will work but very poorly,

So I dug out the foam and piece of ply about 6 inches in diameter at the base of the aerial, then run my copper tape radially from the aerial along the inside of the wardrobe going as far as I could, the vertical one ran down the rear almost to the boiler, their I soldered a earth strap down to the chassis,

make sure you have good continuity between all the tapes so they work as one.

Dabonwheels supplied me extended cables so to minimise connection and these were long enough to reach the radio after many hours of removing trim,

Well at long last I have a radio fit for purpose,it picks ups all my normal stations and many more I didn't know existed,
It's just so frustrating on a MH costing many thousands of pounds that the Manufacturers couldn't be bothered to fit a purpose made aerial properly to the roof in the first place, It would have cost them very little and saved lot of hard work,


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## wakk44 (Jun 15, 2006)

Have you considered internet radio on a smartphone or tablet/laptop?

It is fairly data hungry but I have a decent monthly data package so can use it for several hours a day without exceeding my allowance.Of course it would be ok if connected to a campsite wi fi.

I have fitted a new head unit with bluetooth and simply connect the smartphone to the stereo with it.Reception and sound quality is invariably excellent,it will be useful when abroad and connected to a campsite wi fi to keep in touch with the UK.

The Tunein radio app enables you to listen to numerous radio channels around the world,you could listen to your local radio station wherever you are providing you have a decent internet connection.


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## flyinghigh (Dec 10, 2012)

I do listen to internet radio/TV when parked up but all I wanted was descent reception to normal channels i.e. Radio2/3/4 classic/ smooth when driving around the UK,
I have no problem with my three cars all varying in ages up to 25 years 
So why should I have to tolerate such poor reception on a vehicle that cost 5 times the price of my house?

But now it works very well on all FM/AM and DAB so that's all sorted,
If the manufactures had incorporated an aerial on the initial build it would be simplicity to connect too for very little money IMHO


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## tugboat (Sep 14, 2013)

deefordog said:


> Had a bit of time to spare today so ran a temporary coax cable from the back of the radio to the Status aerial. With the ignition/engine off, picked a weakish station with fairly good clarity and it was about the same as when using the external aerial.
> 
> Turned the ignition/engine on and hey presto, still good clarity. So this seems to be my solution as per gary1944 above. Have run the coax down behind the dash, under the cab carpet, up to behind the o/s overhead lockers and around a corner into a cupboard where the Status amp is above the fridge/freezer.
> 
> Looks OK but more importantly, there's zero interference from the engine. The proof will be when we're on the move - will let you know how it fairs in the near future.


Howja get on on the road then, Deefer?


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## deefordog (Dec 31, 2013)

Sorry Tugboat, only just seen your question.

Reception is better, at least now we have some stations on the move but this is with the Status TV amp off, The amp goes off as soon as you start the engine as I think this is how it's designed to work.

So not perfect but better and just about tolerable but nowhere near as good as I've had previously in 10 year old cars with audio components to that era.


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## Pudsey_Bear (Sep 25, 2008)

deefordog said:


> Sorry Tugboat, only just seen your question.
> 
> Reception is better, at least now we have some stations on the move but this is with the Status TV amp off, The amp goes off as soon as you start the engine as I think this is how it's designed to work.
> 
> So not perfect but better and just about tolerable but nowhere near as good as I've had previously in 10 year old cars with audio components to that era.


Have you tried powering the Status to see what it's like on the move?


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## deefordog (Dec 31, 2013)

Kev - not as yet but it's on the " to do" list. Can get a 12v supply from the adjacent Sky box which, IIRC, is independent of the hab electrics and control panel.


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## Gary1944 (Feb 21, 2009)

deefordog said:


> Sorry Tugboat, only just seen your question.
> 
> Reception is better, at least now we have some stations on the move but this is with the Status TV amp off, The amp goes off as soon as you start the engine as I think this is how it's designed to work.
> 
> So not perfect but better and just about tolerable but nowhere near as good as I've had previously in 10 year old cars with audio components to that era.


Thats really strange deefordog, mine works great now and the RDS actually retunes on R2 for instance. I have not changed the box to power up when on the move so as we still have the original Swift supplied radio should be much the same as yours. Might be worth a quick check on the connections. I guess you used the FM co-ax connector on the Status box.

Good luck,

Gary.


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## The-Cookies (Nov 28, 2010)

I did what someone on here recommended , connected the aerial to the roof tv aerial, fantastic reception , even better if booster is turned on

John


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## flyinghigh (Dec 10, 2012)

I have completed my trip to Scotland via Salisbury and Worcester and very happy with the radio reception both DAB and FM,

The DAB had no drop outs on LBC/ Smooth/radio 4.3.2 when I switch between them, even at the boarder were I usually lose FM it was useable but the DAB was first class,
Their were many other stations available but not really to my taste,

but the ones that interest me were strength 5 so I am at last satisfied with the radio and aerial installation at long last,


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