12 volt tv

suandrews999
suandrews999 Forum Participant Posts: 8
edited March 2016 in Parts & Accessories #1

Hi all, not sure I'm posting this in the right place! I have bought a 22" cello 12 volt tv and when running off my, new, 110amp battery I get no TV signal. The  integrated DVD player works fine.  When plugged in to hook up it works fine through the 12v plug
socket. I've tried a friends avtex 19" TV and the same problem happens. Please help...I'm confused!

Comments

  • Vicmallows
    Vicmallows Forum Participant Posts: 580
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    edited March 2016 #2

    I think you are saying that the TV (receiving normal terrestrial digital TV) works when you are plugged into EHU (even though the TV is working off 12v), but not otherwise?

    If so, you have  inadequate signal strength, and adding an earth connection via the EHU just happens to result in a slightly better signal at the TV .....not unusual at RF frequencies. (Remember, that with digital you either get a picture ...or nothing at all).

    By coincidence, only the other day I was investigating why one TV socket on my (new to me) 10year old van didn't work. I found the outer of the coax to that socket was not ... and never had been ... connected. Obviously previous owner(s) had never used that particular socket.  I can well imagine that causing the symtoms you have.

     

     

    I suspect you are either in a poor signal area and the aerial is inadequate; or you have a fault in the aerial/wiring/amplifier(if any).

  • suandrews999
    suandrews999 Forum Participant Posts: 8
    edited March 2016 #3

    Thanks for your reply. So is there a solution to this problem? If I was to run a socket from my solar panel controller would that do it?

  • peedee
    peedee Club Member Posts: 9,395 ✭✭✭
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    edited March 2016 #4

    So what you are saying is it works fine when you are on EHU but not so when not. If this is correct then it is not an aerial problem. I think it is more likely the TV. If it is not a travel TV designed to work from a battery and is in fact one designed to work from 230volt rather than 12volt it probably cannot cope with the range of voltage experienced from a fully charged 12volt battery (12.6v) to that of a one which is fully discharged (11.8v) I would suspect your battery voltage is the cause of the problem. Have you checked it is fully charged?

    peedee

  • suandrews999
    suandrews999 Forum Participant Posts: 8
    edited March 2016 #5

    Thanks for your reply I don't think it is a TV problem as I have tried another, avtex, TV. It is a cello 12v TV so is designed to run off a battery also the TV works in a friends van. The battery is fully charged and brand new

  • Boff
    Boff Forum Participant Posts: 1,742
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    edited March 2016 #6

    As the DVD works it obviously isn't a voltage problem.   

    I have no solutions only a couple of observations.  

    We have realised that our TV looses signal when a specific spot lights are switch on. We have 4 seamingly identical spotlights and two cause this problem.  This would be a major problem but as one light is at the front where my wife sleeps and the other
    is her side of the bed, it's not a problem for meHappy  But maybe you should switch as much 12v off to see if it is something specific. 

    Secondly we were on a site where the tv reception wasnt great there was a power cut and we couldnt get a signal during the power cut.  I think that the power supplied to the signal booster was reduced.  It might be worth checking that the power supply to
    the aerial is working correctly and I suppose that the power supply was from the 12v supply and not via a transformer on the 230v line.   But it would be really weird if that was the case. 

  • suandrews999
    suandrews999 Forum Participant Posts: 8
    edited March 2016 #7

    I was actually outside our house getting the van ready for easter! I literally only had the TV on nothing else! I'm getting more confused!! If I plug into the ehu is the 12v plug socket not still 12v?

  • peedee
    peedee Club Member Posts: 9,395 ✭✭✭
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    edited March 2016 #8

    The only thing I can suggest is you check the voltage at the 12v socket both when on EHU and when not. Is there any wide difference? Its odd the DVD works on 12v and the Avtex doesn't work either except on EHU.

    peedee

  • Boff
    Boff Forum Participant Posts: 1,742
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    edited March 2016 #9

    I was actually outside our house getting the van ready for easter! I literally only had the TV on nothing else! I'm getting more confused!! If I plug into the ehu is the 12v plug socket not still 12v?

    Sorry I didn't explain myself very well.  The 12v sockets should be arround 12v whether pluged into ehu.   The exact voltage depends on the state of charge of your battery or what voltage the ehu is putting into your battery.  But I can't see why a voltage
    diffce would effect Tv's reception but not the DVD working. 

    What I mean  about the power supply. The aerial should have a built in booster that needs a power supply, I am only familiar with the status Ariels but I assume they are all similar.   This power supply should be 12v. This should be wired into the vans 12v
    system normally directly.  However if the 12v for the aerial is supplied by a plug transformer IE something that converts 230v to 12v then this would be a possible explanation.  It is most unlikely but should be easy to check by either, tracing the power lead
    that goes into the aerial.  Or if there are any lithat that light up  on the aerial / booster when plugged into ehu but aren't lit when you are aern't.  Logical the problem has to be related to the aerial and not directly to the Tv  

  • suandrews999
    suandrews999 Forum Participant Posts: 8
    edited March 2016 #10

    Thanks all I think I've got some further investigating to do!!

  • commeyras
    commeyras Club Member Posts: 1,853 ✭✭✭
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    edited March 2016 #11

    Boff has explained a possible solution very well.  Basically you need to turn the aerial on!  You should find this magic box in a cupboard near where the aerial enters the caravan it will have aerial leads coming in and going out;   if it is a Status aerial
    it will have 2 switches on the bottom one on/off and the other low/high power - try high power.

  • suandrews999
    suandrews999 Forum Participant Posts: 8
    edited March 2016 #12

    Yeah it was on maybe it is the way it's wired in?! And I've tried it on high and low.

  • Vicmallows
    Vicmallows Forum Participant Posts: 580
    500 Comments
    edited March 2016 #13

    The simple and definitive way to establish if it is a 'van aerial/wiring/amplifier related problem is to get hold of a basic standard TV aerial, a length of coax and a plug. Connect this aerial DIRECTLY to the TV. (Obviously you must be somewhere where you know you would normally get a reasonable signal, and point it in the right direction).

    If the TV now works OK, you can work forwards along the installed wiring until you find the problem.

    Basic aerials can be bought for about £10, and will also be useful on a pole if you are in a poor reception location.

     

     

  • peedee
    peedee Club Member Posts: 9,395 ✭✭✭
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    edited March 2016 #14

    I would still eliminate any possibility of the problem being 12v voltage differences betweem mains and battery. It is simple enough to check this before considering more complex issues.

    When you eventually get it sorted, I hope you will let us know what the problem was.

    peedee

  • peedee
    peedee Club Member Posts: 9,395 ✭✭✭
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    edited March 2016 #15

    Yeah it was on maybe it is the way it's wired in?! And I've tried it on high and low.

    Did you ever find out the cause of the problem?

    peedee

  • suandrews999
    suandrews999 Forum Participant Posts: 8
    edited March 2016 #16

    Not got to the bottom of it yet hopefully gonna look at it this weekend

  • Boff
    Boff Forum Participant Posts: 1,742
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    edited March 2016 #17

    Could you please keep us updated.  It is always nice to know how a problem is resolved.  Even if the solution is to trade the caravan in for a new one. Laughing

  • suandrews999
    suandrews999 Forum Participant Posts: 8
    edited March 2016 #18

    Quick update.....I've tried the TV with a stand alone Ariel and......it worked so I guess the status booster is wired up incorrectly but as long as I know I can use the TV I'm happy. I'll just get them to have a look at the booster next time the van is serviced!
    Thanks all for your help and advice

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