Runboard.com
Слава Україні!
Community logo


runboard.com       Sign up (learn about it) | Sign in (lost password?)

Page:  1  2  3  4 

 
topbuzzuk Profile
Live feed
Blog
Friends
Miscellaneous info

Big Cheese

Registered: 11-2007
Location: Wiltshire, UK
Posts: 2655
Karma: 12 (+12/-0)
Reply | Quote
Wire antenna questions


hello, i was just wondering what the best kind of wire is to use building, probably a 1/4 wave antenna in the loft. also how do you go about gettin as good a bandwidth you can(low mid high)? anyone got any links to diagrams or info? cheers

Paddy

---
26FB118
11/Mar/2008, 9:00 pm Link to this post Send Email to topbuzzuk   Send PM to topbuzzuk Yahoo
 
yamanx1 Profile
Live feed
Blog
Friends
Miscellaneous info

Head Honcho

Registered: 09-2007
Location: In a world of my own
Posts: 4894
Karma: 40 (+41/-1)
Reply | Quote
Re: Wire antenna questions


I can do this for you, just give me a good idea of the size of your loft, and I'll work something out for you emoticon

---

By all means think yourself big, but never think others small.... R.F.Scott
11/Mar/2008, 9:05 pm Link to this post Send Email to yamanx1   Send PM to yamanx1
 
topbuzzuk Profile
Live feed
Blog
Friends
Miscellaneous info

Big Cheese

Registered: 11-2007
Location: Wiltshire, UK
Posts: 2655
Karma: 12 (+12/-0)
Reply | Quote
Re: Wire antenna questions


i'll have a measure tomorrow dave, i think its about 9-10 foot high and the room to play with is 20 x 20 foot give or take a few low bits in roof space.

---
26FB118
11/Mar/2008, 9:27 pm Link to this post Send Email to topbuzzuk   Send PM to topbuzzuk Yahoo
 
soundmanjim Profile
Live feed
Blog
Friends
Miscellaneous info



Registered: 01-2008
Posts: 230
Karma: 4 (+4/-0)
Reply | Quote
Re: Wire antenna questions


your just about ok. one vertical element made out of stripped back mains wire, 4 9 foot radials out of more stripped wire, something heavy on the bottom and hang it from a hook at the apex, spread the groundplanes out, solder the inner of the coax to the upright and join the g/plane wires together and solder the outer to taht - should work a treat. vertiocal bit should be about 9'6"

---
If it Aint broke, don't fix it, and if you do, don't tell anyone you touched it
11/Mar/2008, 10:48 pm Link to this post Send Email to soundmanjim   Send PM to soundmanjim MSN
 
yamanx1 Profile
Live feed
Blog
Friends
Miscellaneous info

Head Honcho

Registered: 09-2007
Location: In a world of my own
Posts: 4894
Karma: 40 (+41/-1)
Reply | Quote
Re: Wire antenna questions


I think the best performance for space and for indoors is going to be a loop antenna. A wire one of these will only take a couple of hours to make and minimal materials required.

Theres loads of weird and wonderful loop antennas here, if you fancy building one I'll help where I can, I can certainly lay my hands of the bits emoticon

Clicky link


---

By all means think yourself big, but never think others small.... R.F.Scott
21/Mar/2008, 6:57 am Link to this post Send Email to yamanx1   Send PM to yamanx1
 
Hot Fusion Profile
Live feed
Blog
Friends
Miscellaneous info

Management

Registered: 03-2008
Location: South West England
Posts: 1389
Karma: 7 (+7/-0)
Reply | Quote
Re: Wire antenna questions


Tips on improving bandwidth.

Two ways this can be done:

Increase the diameter of the vertical element drastically - I'm talking about using a piece of aluminium scaffold/antenna mount tubing or metal drainpipe for the element. Can be done, and works well. Bit of a bugger to fine tune though due to the cutting bit...

The other is to use two verticals next to each other, both connected together to the inner of the coax at the lower end and slightly separated at the top. Cut to slightly different lengths to reflect the frequencies you wish to cover.

---
Andy - FB107
24/Mar/2008, 11:56 am Link to this post Send Email to Hot Fusion   Send PM to Hot Fusion
 
yamanx1 Profile
Live feed
Blog
Friends
Miscellaneous info

Head Honcho

Registered: 09-2007
Location: In a world of my own
Posts: 4894
Karma: 40 (+41/-1)
Reply | Quote
Re: Wire antenna questions


Found this:

Loft wire antenna, simple dipole, but with a bit more detail of how to build it for 11m

clickerage to wire dipole


---

By all means think yourself big, but never think others small.... R.F.Scott
25/Mar/2008, 7:47 am Link to this post Send Email to yamanx1   Send PM to yamanx1
 
topbuzzuk Profile
Live feed
Blog
Friends
Miscellaneous info

Big Cheese

Registered: 11-2007
Location: Wiltshire, UK
Posts: 2655
Karma: 12 (+12/-0)
Reply | Quote
Re: Wire antenna questions


cheers dave, that is one of the easieest explanations ive read on the net. i'll have to get some wire sorted and have a go

---
26FB118
25/Mar/2008, 10:41 am Link to this post Send Email to topbuzzuk   Send PM to topbuzzuk Yahoo
 
topbuzzuk Profile
Live feed
Blog
Friends
Miscellaneous info

Big Cheese

Registered: 11-2007
Location: Wiltshire, UK
Posts: 2655
Karma: 12 (+12/-0)
Reply | Quote
Re: Wire antenna questions


howdy, ive been puting a wire antenna up in the loft and really want some help. i could of made a simple 1/4 wave but decided to try and make a 1/2 wave(2x17'ish elements). now swr seems to be a problem unless i only have the center pin of coax plug connected to swr meter, this tells me there is a short but both patch leads are fine and so is the coax to the antenna. ive been reading about 1/4 dipoles and something to do with the ohms at feedpoint. any ideas help or pointers that may help me out apreciated emoticon

---
26FB118
16/Apr/2008, 3:15 pm Link to this post Send Email to topbuzzuk   Send PM to topbuzzuk Yahoo
 
Hot Fusion Profile
Live feed
Blog
Friends
Miscellaneous info

Management

Registered: 03-2008
Location: South West England
Posts: 1389
Karma: 7 (+7/-0)
Reply | Quote
Re: Wire antenna questions


Is this antenna for 11 metre use? If so, the lengths are wrong. You need to have two wires of approximately 8'6" long, one attached to the coax outer, the other to the inner.

You SWR the antenna by trimming EQUAL amounts off the ends (or adding it...).

Ideally you should include a choke balun to eliminate RF on the coax outer and to force the antenna to act in a balanced manner. I expect there's a bit of info on choke baluns about if you google for it.

For the record, I'm about to fit up an inverted 'V' in the loft - no idea yet how it will perform due to the slate roof, but I suspect it will be easily as good as anything else I can get up there.

I'll take some photos when I do it and post them if anyone's interested. emoticon
16/Apr/2008, 8:06 pm Link to this post Send Email to Hot Fusion   Send PM to Hot Fusion
 


Add a reply

Page:  1  2  3  4 





You are not logged in (login)