yamanx1
Head Honcho
Registered: 09-2007
Location: In a world of my own
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The Aerial
This is probably the single most important bit to get right.
There are many many different shapes and sizes of antennas on the market, but in the end the bigger the better, there just is no compromise on the size. A small aerial claiming to have the performance of a big antenna aint going to happen.
Because of space and other factors like neighbours etc, most people fit a vertical aerial, again the bigger and the higher the better it will work for you. But even a simple Silver Rod can work very well indeed for DXing.
Vertical aerials are omni-directional, which means they will receive and transmit in all directions.
One of the most important things is to get your SWR as low as possible. Do not compromise here. SWR is the amount of power that is emmitted from the aerial. The higher the SWR the more power is being reflected back into the radio. SWR is measure as a ratio so even a small amount of reflection can mean a big loss of power out.
Mounted your aerial as high as you can and try and get the base at least a bit higher than the surrounding TV aerials.
Use good coax and keep it as short as you need.
For far better results when DXing and if you have the space, Horizontal aerials are best. From single element to five or even more elements. These antennas are directional and will only recieve and transmit in the direction they are facing, so usually require some means of rotating.
There are also many other types of aerial, wire, quads, loops etc. But at the beginning I would advise either a vertical (Remember the bigger you go the better) or a single element horizontal dipole such as the SY27 Shown here mounted vertical for omnidirectional use. If you go for this antenna mount it horizontal for DX work
This single element SY27 will be directional in two directions, if you cant mount a rotator, and only a cheap TV one will do the job, then North South will give you best results most of the time.
However becaue most people use verticals, local ground wave contact will best be made from a vertical. The SY27 wont work very well for local contacts, but better for DX.
If you do go for a vertical something like this is a good compromise for both local and DX work. Its easier to install than a directional beam, takes less space and is ideal for someone new to DX work. It is very big!!
Alternatively if space is tight and you still want to DX on the 11 metre band a silver rod will still get you out there when conditions are favourable.
So as big as you can, as high as you can and the SWR as low as possible. Good coax, you'll get what you pay for here.
Best with a beam or horizontal, but still good with a vertical. For local as well as DX vertical, for DX only horizontal.
There are other alternatives, but the range is immense, to get started I would advise something of the above
---
By all means think yourself big, but never think others small.... R.F.Scott
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8/Mar/2008, 11:00 am
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devondave
Registered: 03-2008
Posts: 89
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Re: The Aerial
ok just won a lincoln!!!
now which antenna?
is there much difference between the sirio megawatt 3000 and the 4000? apart from £20!
cheers
dave
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8/Mar/2008, 6:12 pm
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soundmanjim
Registered: 01-2008
Posts: 230
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Re: The Aerial
just that - £20 and its got more radials i think - i think the imax 2000 is a good idea as they are a bit more non sus than a silver rod or a sirio - but tey can whip about a bit in the wind. leave any antenna fixuing up until after monday night - theres a big gale coming!!!
--- If it Aint broke, don't fix it, and if you do, don't tell anyone you touched it
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9/Mar/2008, 10:56 am
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devondave
Registered: 03-2008
Posts: 89
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Re: The Aerial
thanks for that but its a mobile antenna?
just want something on the lid of the car i can park up somewhere high and go for it!
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9/Mar/2008, 7:13 pm
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soundmanjim
Registered: 01-2008
Posts: 230
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Re: The Aerial
oh i see.
well if its a mag mount, find a square of steel, drill 4 holes in the corners, then attatch 4 pieces of any decent electrical wire to that.
Mag the antenna onto the square bit of steel.
Place the whole thing on the ground, and stretch the wires straight out away from the square and that should work good! its how i used to do it in the 80's!
--- If it Aint broke, don't fix it, and if you do, don't tell anyone you touched it
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9/Mar/2008, 8:18 pm
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topbuzzuk
Big Cheese
Registered: 11-2007
Location: Wiltshire, UK
Posts: 2655
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Re: The Aerial
lol, i think he wants a mobile for a car jim
i have a 3000 and my friend has a 4000 one is about 30cm longer than the other, apart from this they are pretty much the same. obviously longer is better but we hear the same stations when we are sat next to each other. I think they are good antennas and if you want better, get a 2 piece 9 foot whip to just plug on adapter for magmount when you park up. i have an adaptor that converts the magmount to take a 3/8 threaded antenna so for dx use a 9 footer. (*note to self"buy a 9 foot whip"*)
--- 26FB118
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10/Mar/2008, 2:17 pm
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devondave
Registered: 03-2008
Posts: 89
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Re: The Aerial
right well i have brought a 3000 im sure i never had problems in the past when i worked a dv27! i can recall working wales on the ground wave from a hill top using just the dv27 and 4w! if i get it all set up by the weekend i will take to a hill and see who i can hear!
if anyone else is planning taking to a hill let me know when and i will do my best to get back to you
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10/Mar/2008, 3:06 pm
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soundmanjim
Registered: 01-2008
Posts: 230
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Re: The Aerial
ok dave, whereabouts in devon roughly are you?
--- If it Aint broke, don't fix it, and if you do, don't tell anyone you touched it
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10/Mar/2008, 11:13 pm
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devondave
Registered: 03-2008
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Re: The Aerial
im right down on the south coast of devon so i presume the best place to head from here will be dartmoor! its a lonely place up there though
i do know some areas where i will reach portland isle of wight that area pretty well but i cant seem to find any members of cb forums from those kind of areas so i am looking for areas to transmit northwards!
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10/Mar/2008, 11:59 pm
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topbuzzuk
Big Cheese
Registered: 11-2007
Location: Wiltshire, UK
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Re: The Aerial
you might get hold of me dave, i'm about 3 miles east of stonehenge not far from the A303. I go over Salisbury plain most weekends in the 4x4 so probably be able to get me if you was on high ground.
--- 26FB118
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11/Mar/2008, 12:10 am
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