How to Make a DAB Radio antenna

Discussion in 'How To' started by scotjimland, May 5, 2011.

  1. scotjimland

    scotjimland Funster Life Member

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    We live on the very fringe of DAB radio reception and have tried several indoor antenna with little success and was resigned to having to fit a roof antenna but decided to search the net for a home made one..

    When I read the instructions, I was to say the least a tad skeptical .. but as it was only a few minutes to make and cost next to nothing decided to give it a try and bingo .. perfect reception all DAB stations, including my fav Planet Rock .. :Cool::thumb:

    So, here are the instructions..

    You need.

    about 3 mt 75 ohm coax aerial cable.
    one F plug or whatever your plug fits your receiver


    1. Strip both outer insulation and the braided shield from 300mm/12ins of one end of the cable, just leaving the insulated inner core.

    2. Carefully strip the outer sheath from the next 230mm (9ins) of the cable, making sure the braid isn't broken. Wrap a little tape around where the shielding braid meets the stripped inner to stop it unravelling.

    3. At that point, where the cable is fully insulated, make a coil of two turns of the remaining fully sheathed cable. The diameter of the coil should be 50mm (2ins).Secure the coil to stop it unwinding with insulation tape.

    4. Attach the 'F' or UHF/VHF plug to the untouched, longest end. Tape a loop of string or whatever to the top thin end, so you can hang the finished aerial vertically from a nail or drawing pin in the wall as per aesthetic preference.

    Don't ruin it by letting the uninsulated braid touch anything metallic; and don't coil the long end of the cable!

    Plug in to your tuner's DAB antenna socket. You will probably now receive all your 57 or whatever stations at a much higher signal level than using a dipole or 'T' aerial. And probably better than a pricey amplified set-top gizmo.

    That's it.
     

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    Last edited: May 5, 2011
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  2. Jim

    Jim Ringleader

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    Not a single DAB station where we live.:Sad: We can and do transmit stuff all around the world and beyond, but not to Wales:RollEyes:
     
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  3. Dodgey

    Dodgey Funster

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    Awsome, PR, err rocks:thumb:

    Jim, PICTURES, come on:BigGrin:
     
  4. scotjimland

    scotjimland Funster Life Member

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    pictures of a piece of coax ? .. or were you thinking something more ...err erotic :Laughing:

    but.. in the name of science I will oblige ...

    Now where's me Box Brownie ... and no funny remarks either ... :Wink:
     

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  5. Dodgey

    Dodgey Funster

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    :Rofl1: As the saying goes, a picture says a thousand words:thumb:
     
  6. Chris

    Chris Funster Life Member

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    My parents live in Pembrokeshire Jim. A few years ago I thought I would treat them at Xmas to a stonkingly expensive DAB radio. No reception:Sad:

    Still Mum thinks it picks up medium wave better than her old one - Bless her.
     
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  7. Douglas

    Douglas Read Only Funster

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    If you put your dipole antenna into a plastic tube making sure its stretched out stright, seal both ends with mastic, you will be able to use it out side, even on the MH.

    Doug...
     
  8. scotjimland

    scotjimland Funster Life Member

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    Good idea Doug.. :thumb:

    I might just do that for the house and stick it outside rather than hang on the good wallpaper.. :Laughing:
     
  9. octopush

    octopush Read Only Funster

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    Antenna

    I bought a dab radio for my shop and was disappointed that i could not receive any stations.

    so i went on a search and found this.

    As i read it i thought there would be no way it would work as it was to easy and simple to make in just 5 mins.

    So i gave it a go and was ready to be disappointed BUT NO it actually worked not just ok but perfect.

    So thank you for posting this a long time ago.

    It was handy it bought me to this site as we are just starting to look for a camper.

    Thanks
    Rob

     
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  10. scotjimland

    scotjimland Funster Life Member

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    Thanks for taking the time to thank me.. glad it was a success.. :Smile:

    and good luck in your search for a camper, you will get plenty of good advice on here .. well worth the ten quid subs :thumb:

    here is a pic of mine fitted inside a piece of plastic tube and mounted outside..
     

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    Last edited: Sep 29, 2012
  11. hilldweller

    hilldweller Funster Life Member

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    Would any of our hams like to verify that (2) is nonsense.

    Stripping the insulation makes no difference, radio waves penetrate it.

    Doug mentioned "dipole", it looks like a dipole but it isn't.

    Dipole would be......
    [ ignore . and __ these are just spaces]
    This is horizontal, rotate 90 deg. + = screen, - = inner

    ==================__==================
    ......................................+__-
    ......................................+__-
    ......................................+__-
    ......................................+__-
    ......................................+__-
    ......................................+__-
    ......................................+__-
    ......................................+__-
    ......................................+__-
     
  12. octopush

    octopush Read Only Funster

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    Before i had found this post i tried it without stripping the outer and found i could not get a signal .

    So for me it worked stripping it.

    Anyway if it works without stripping it why bother with an Ariel at all as you could just run the wire straight up your wall

     
  13. buttons

    buttons Funster

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    My prob is my expensive DAB has no aerial socket. Just a thin black wire that hangs and does little:Sad:
     
  14. octopush

    octopush Read Only Funster

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    If you get no reception and if it was me i would attach a socket to it or just strip the wire and twist some coax on to them and see what happens you have nothing to loose.


     
  15. hilldweller

    hilldweller Funster Life Member

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    You didn't read it properly, No.2 deals with stripping just the plastic outer.
     
  16. scotjimland

    scotjimland Funster Life Member

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    I appreciate what you are saying Brian ..

    I see no reason why taking the lower part of the outer sheath off would make any difference and in my final version the whole lot is sealed inside a PVC pipe..

    To be frank, not being a 'ham' never gave it much thought .. but the main thing is it 'works' .. and a year on is still performing well.. the same design could be used for a camper van ..
     
  17. Pigwam

    Pigwam Read Only Funster

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    well I know all the theory and made many aerials over the years and always thought that aerial making is a bit of an art form, although for some its a gift and everything they make just works.

    Brian's right it doesn't look like a Dipole to me and I don't see why the outer insulation makes a difference unless its due to the screen is now acting as a reflector.

    However overall its a tuned circuit and it seems to work well, so for less than a fiver you've got nothing to lose.

    maybe this is one for 'Peteac' to answer as he seems to be very knowledgeable with aerials.

    I do remember when the BBC were first doing trials on DAB and improving reception they noted that by placing the radio on a large metal tray - or even aluminium cooking foil it can act as a sort of reflector and add something to the signal strength.

    but for me I just added a length of wire to the telescopic aerial and reception improved, obvious i needed to strip back the outer and just wrapped the bare wire around the top of the aerial.
     
  18. reader

    reader Funster

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    I have both vertical and horizontal coax dipoles (in plastic tube with capped ends) that I use on the 4m band and the dipole ends are not stripped. I do have the feeder going through a balun at the feed point.
    I have worked various regions in the UK and parts of Europe with these aerials which were all made from scrap!

    Must admit though our DAB broadcast radio uses a bit of light gauge wire out the back of the set.
    My amateur digital transceiver works through a 70cm band co-linear at around 30ft above ground level
     
    Last edited: Sep 29, 2012
  19. philw111

    philw111 Funster

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    You have to experiment.

    Officially (according to the various websites) we don't receive a DAB signal here at all. If I fully extend the aerial, sure enough, the signal is very poor. If I put the aerial partly down, retracting the thinnest part at the top (this is obviously important) I get excellent reception.:Eeek:

    I haven't tried to make one of these aerials, mainly cos I've just bought an internet radio:thumb:

    Phil
     
  20. camper

    camper Read Only Funster

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    short wave

    I've given up on digital.
    Mainly I live in manchester and I have tried 3 differentDAB radios and finally bought a Roberts one which i was assured was one of the best.It has lots of nice features but is often "bubbly" even on bbc radio.If I tune into fm with same radio all channels are perfect.So I don't bother travelling with it.
    Generally in the lake District reception is poor- usually Classicfm only with lots of interference.Is a short wave radio worth investigating?
     
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