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ripstop Profile
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Registered: 05-2008
Posts: 4
Karma: 0 (+0/-0)
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need help with antenna


hi all, what is the best mobile antenna to use . ive got a landrover defender and have problems with swr, its high tried to earth it but that did not work, anyone had same problem, need to get mobile live in built up areea and need to try new rig out ss-158EDX this is my first rig and need to get a contact, any advice would be great!!!
thanks
19/May/2008, 11:26 pm Link to this post Send Email to ripstop   Send PM to ripstop
 
yamanx1 Profile
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Head Honcho

Registered: 09-2007
Location: In a world of my own
Posts: 4894
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Re: need help with antenna


Paddy, topbuzz, is the best person here to help. He had exactly the same issues with a Landy. I'm sure he cured the problem by running earths and running the rig direct from the battery emoticon Also I think he changed from a mag mount, not sure.

What antenna are you trying to use? With which mount?

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By all means think yourself big, but never think others small.... R.F.Scott
20/May/2008, 9:40 am Link to this post Send Email to yamanx1   Send PM to yamanx1
 
topbuzzuk Profile
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Big Cheese

Registered: 11-2007
Location: Wiltshire, UK
Posts: 2655
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Re: need help with antenna


hi, i have a discovery and had a bit of fun getting swr down. yours is all alloy so probably worse.

right first i would check all the earths from the battery to the chassis and body(i added a couple of new ones to the inner wing and chassis from -terminal)try also fitting a earth strap from the chassis to the body somewhere underneath toward the rear.

next i would wire the radio straight to the battery with suitable ampage cable, also get a clip-on ferrite choke or a ferrite loop and wrap the wire round it a couple of times near the battery end(i have used a choke on anything wire in my mobile to do with radio even ext speaker as that caused rf wierdness)

antenna- well a mag mount is not an option so this will have to be fitted somewhere more permanant, if all the chassis/body earths are ok you should be able to either use a gutter mount or fix straight into roof. remember to remove paint so gutter mount screws touch bare metal, or if fitting in roof remove paint to make a good electrical contact. landrovers are all alloy and i know its not the best conductor so may or may not work its best. something my friend did in his landrover was use a roof bar and a mirror type mount, this gave the antenna something steel to be bolted to. he then ran a earth wire from the antenna mount to a good earth inside the landy, this seemed to work best for him.

i have my antenna on the roof bar on my disco and this is the best place i have found. i was having swr problems and rf feedback with a gutter mount and a mag mount, mostly it was down to bad earthing and the roof being steel while the body is alloy(made strange things happen). i guess the roof bar on the disco is fixed to a good structurel point and has a good earth.

the best antenna depends on what you do and where you go, if its hitting stuff alot then i would get something cheapish and springy(if your offroading alot). I own a Sirio megawatt 3000(baseloaded)which was good but on a magmount and i use a Moonraker SC5000, this is solid for about a foot and a half so no good for offroading but works a treat(cheap on ebay too)has standard 3/8 thread

Image

>ebay linky<

EARTHS EARTHS EARTHS <<< and stick RF chokes on the coax, power leads if you use a power mic stick one near the plug. i got em everywhere but it sorts out interference and rf feedback a treat

EDIT* oh make sure you run the coax close to the sides and floor, i found if the coax was out in the open or able to move about, so did my swr. problems got worse with more power, but its sorted now all ok, i would go down the roof bar root and earth everything lol
 emoticon

Last edited by topbuzzuk, 20/May/2008, 11:43 am


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26FB118
20/May/2008, 11:38 am Link to this post Send Email to topbuzzuk   Send PM to topbuzzuk Yahoo
 
ripstop Profile
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Registered: 05-2008
Posts: 4
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Re: need help with antenna


thanks for the info, ive got a tornado type springer at the mo thougth the roof, i will take your advice and fit ferrite clip ons,check for a better earthing point and will look at getting a more suitable antenna. not to bothered about removeing it when off roading, i might try fitting it to a bracket on front of the landy a bar to see if i get a good swr?.
i want to use mobile as a can drive up to the hills , i live in a bulit up area.
thanks agian ripstop.
20/May/2008, 3:50 pm Link to this post Send Email to ripstop   Send PM to ripstop
 
topbuzzuk Profile
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Big Cheese

Registered: 11-2007
Location: Wiltshire, UK
Posts: 2655
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Re: need help with antenna


i think on the front a bar will be quiet a good earthing point for the antenna, straight to the chassis. i used to use a tornado springer but i like the moonraker better as it is a bit more stable and doesnt whip about so much effecting signals. i havnt been serious offroading for a month or so, so havnt had to take it off. I paid about £4+postage for my antenna off the same guy on ebay, just keep watching them a cheap one always goes. emoticon

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26FB118
20/May/2008, 5:03 pm Link to this post Send Email to topbuzzuk   Send PM to topbuzzuk Yahoo
 
26fb010 Profile
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Accomplished DX-er

Registered: 01-2009
Location: BLACK COUNTRY
Posts: 574
Karma: 3 (+3/-0)
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Re: need help with antenna


the longer the physical length of the antenna, the better it will work (simple fact)
but tune it in real good... bute
30/Jul/2009, 10:24 pm Link to this post Send Email to 26fb010   Send PM to 26fb010
 
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Freebander

Registered: 06-2010
Location: Sheffield. The Steel City.
Posts: 220
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Re: need help with antenna


I run a mobile set up in the wagon,and my swr is fine,less than 1.4.
I am running at 30watts on SSB with a long coil modulater,or red devil as some call it.
I have contacted stations in Croatia,Norway,Estonia,Poland,and some more local all while driving.So once you get a decent SWR reading and a good antenna your well away.
 Dont give in,it does take time,but the rewards are good and well worth the initial boring hard work,and once its done,just check you SWR now and then,especially if your antenna is getting hammered with trees,etc.
Craig.


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"Women are like old Lambrettas,you can only push them so far"
4/Jul/2010, 8:37 pm Link to this post Send Email to CraigOWL   Send PM to CraigOWL Blog
 


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