Amateur Radio Antennae

Discussion in 'Motorhome Chat' started by tobytenblue, Mar 16, 2013.

  1. tobytenblue

    tobytenblue Read Only Funster

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    Hello All, :BigGrin::BigGrin::BigGrin:

    Anyone out there using a 2 meter rig mobile. I'd like to install one in the cab of my CI Carioca but can't see how I'm going to fit an antenna (to essentially plastic bodywork). Not a lot of accessable steel on the wings or bonnet to be able locate one either.

    I suspect that someone out there knows how to do it and I look forward to your suggestions.

    Thanks,

    Brian. :BigGrin:
     
  2. Wildman

    Wildman Read Only Funster

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    use a handheld
     
  3. tobytenblue

    tobytenblue Read Only Funster

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    Re handheld

    Thanks for that Roger, :Doh:
    I want to use it mobile, so h/held not much cop, 5 watts into rubber ducky doesn't do it for me. Apart from which I'll have the steering wheel in my hands!
    Brian. :Smile::Smile:
     
  4. Gromett

    Gromett Funster

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    Speak to your local metal guy. Get as much sheet steel (1mm) as you can and use sikaflex to glue it to the roof.

    You can then attach whatever magmount you want.

    Disregard this advice as I am a bit tipsey and will realise the error of my way tomorrow no doubt :Rofl1::Rofl1::Rofl1:
     
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  5. Southampton

    Southampton Funster Life Member

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    Try a dipole construction similar to this link, that way you don't need a ground plane. http://www.comrod.com/getfile.php/Datasheets/Norway Antennas - Marine/AV51BI4.pdf

    Just a thought. I am in the Defence Comms area and we use these dipole style antennas on all non metallic vehicles, but in the military spectrum.
     
  6. cbrookson

    cbrookson Funster

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  7. reader

    reader Funster

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    Feed a coax out of the cab via a grommet under the plastic cover in the cabdoor step and feed to the rear of the van and use a S0239 type mount on the cycle rack. From this take a feed back to the chassis somewhere for a ground plane.

    If you havn't got a cycle rack then either a gutter mount or mag mount on the bonnet ( if you use a long aerial may need a kink in it ) but a small dual
    bander around 18/24ins should be ok

    Other than that a marine type aerial and mount on the body. If you cant get one for around 145MHz a Marine FM band will be close enough through a small atu
     
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  8. tobytenblue

    tobytenblue Read Only Funster

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    Mobile Antennae

    Thanks for the suggestions chaps,

    Glueing steel to the roof doesn't appeal at all so that's out the window! :Laughing::Laughing::Laughing:

    Have considered the chassis ground plane idea but that seems like too much hassle, I can't be doing with that.

    The glass mount seems a better idea, certainly easier, so I've just ordered one. I'll let you know how I get on with it. :thumb:

    Thanks.

    Brian. :BigGrin::BigGrin::BigGrin:
     
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  9. bigfoot

    bigfoot Funster

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    I have one which has a ground plane that screws to the base of the aerial and then into the base mount.
    The one I have is a Wilson Firestik bought from the states. The mobile rally season is about to start one of the dealer may have them. The Northern show is in Blackpool at the Norbreck castle on April 7th.
     
  10. G8WVW

    G8WVW Read Only Funster

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    I have a Panoramic 5/8 PMR aerial mounted into the front wing. Very much a compromised as any installation is in a coachbuilt motorhome. Merc Sprinter base vehicle manual states that the vehicle is designed to cope with fields created by 25W VHF/UHF transceiver and never have any problems there. Philips DAB radio however looses lock during every transmission!
     
  11. Reallyretired

    Reallyretired Funster

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    I have just mounted a CB antenna and a dual band 2m/70cm antenna on the bike rack (well to be honest steveutwg did it)

    thick wire from base of antenna to chassis in each case.

    CB is great, mini springer with SWR of 1
    2m SWR 1.2
    70cm don't ask. (5plus)
    I thus have a theory that when using a ground plane a lot lower than the antenna base the effectiveness in inversely related to frequency.

    If really vital to use 70cm (our local repeater is 70cm) then I think a steel plate glued to the top of the back box and a mag mount will be the answer. I would expect thick enough paint would stop any rusting and anyway you'd need to be 8ft tall to see it.
     
    Last edited: Mar 21, 2013
  12. f1lby

    f1lby Read Only Funster

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  13. Wildman

    Wildman Read Only Funster

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    why not have 2mtr one side and 70cm on the other. Each will act as the others groundplane.
     
  14. Jaws

    Jaws Funster Life Member

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    I simply use a lip mount on the near side of the bonnet
    Allows me to use a choice of antenna I have depending on what rig(s) I have in the motorhome at the time, a
    decent 7/8th wave or dual band triple 5/8th or even swap it over for a chicken box antenna that it currently has on it
     
  15. Jaws

    Jaws Funster Life Member

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    Intersting idea.. and I guess the 2mtr one might well act as a ground plane ( providing it is not on the same access as the 70cms ) as it is a third harmonic, but methinks visa versa may be a bit of an issue LOL !!
    There is also the point that using one to balance the other may well encourage a transmitted harmonic too
     
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  16. Wildman

    Wildman Read Only Funster

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    worth a try a similar arrangement is used in a log yagi antenna
     
  17. f1lby

    f1lby Read Only Funster

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    Using the lower element as a radiator wouldn't be much good as it will effectively be an upside down dipole.
    You could use one of these - http://www.moonraker.eu/amateur-rad...ri-band/mr700-2-70-38th-thread-mobile-antenna

    This is 3/8 thread and dual band - much simpler...
    The initial query was for 2M - I also don't use 70cm in the motorhome so 2M only is good with me.

    I am in the process of changing my antenna configuration with a pole mounted on the bike rack with the mount on the top of the pole, thus ensuring the radiator is above the roof of the motorhome with the intention of increasing forward tranmission coverage (with the antenna in its current position it's shielded by the motorhome).
     
  18. f1lby

    f1lby Read Only Funster

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    And on a side note - Only my MPV I have a roof rack with a sheet of galvanised steel peppered with holes in it - all my aerials attach to this - no holes drilled in the vehicle - the whole lot of antennas attached to the sheet of steel inc 80M and top band.
    I've got aerials & relays for switching all on the roof rack. Works great - if you've an option to fit a roof rack this will give you loads of scope!
     
  19. Wildman

    Wildman Read Only Funster

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    Photo?
     
  20. Jaws

    Jaws Funster Life Member

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    Not a lot of good for me.. I would LOVE to get the antennas up there but with a MH the size of ours that would mean they would catch on over head fone lines ( I know all about this.. Nearly lost an 80 stick to a fone line once ( and that was in the car !! LOL !! )
     
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