Building your own antenna in no time!

[P0tenc]

First read this:
http://www.freeantennas.com/projects/template/index.html
http://www.freeantennas.com/projects/template2/index.html

Reflector should be 120mm(high)x240mm(Wide) Focal point is very important...so experimant.

You can find some pics on the freeantennas website....here is a example of one I built quickly that provides a -6db Gain from -83db to -77db(sometimes -75db).

http://img423.imageshack.us/my.php?image=p0tencparabolicreflector14jw.jpg
(Note antenna is pointing wrong direction for pic)
http://img427.imageshack.us/my.php?image=p0tencparabolicreflector25iy.jpg

Gain can be much higher if you have a weak signal....and point it in the direction of your tower. I recommend using iconnect to see the difference.
http://mybroadband.co.za/vb/showthread.php?t=28356

I hope this helps some ppl.

 

[Freddo the Frog]

Worth a Try

I built one of these as well.

Unfortunately the window of my office does not face the right tower, and towers in that direction are too remote to give a decent signal. There was definitely an improvement but not enough to be worthwhile.

I am sure it will help under the right circumstances and is definitely cheaper than an external antenna. I recommend trying one - it's fun to build and the price is right.

I had to buy a yagi in the end so I could point it over the roof. approx. 12dB of gain which got me from <-90dB to >-80dB.

 

[Ekhaatvensters]

This sounds great but I already use a antenna and still want to increase my signal strength, anyway thats possible? I'm geussing none of your solutions would help.

 

[P0tenc]

Nope......the freeantennas are only for ppl who want a better signal but don't want for spend money on buying a external 1.

I think the only way of increasing gain in your situation Ekhaatvensters is to buy a bigger meaner antenna.

 

[seburn]

Height helps a great deal

 

[noswal]

click my sig, no maths involved

 

[P0tenc]

omw......that the funniest and ugliest antenna I've ever seen.

 

[seburn]

Did you use tin foil or aluminium

 

[P0tenc]

Tin foil

 

[GRES]

This "antenna" has 3dBi Gain in theory. 2-2.5dB in practice. Instead of 360 degree it sends signal to 180. 2 times more specific energy per same angle.

 

[vukko]

Height helps a great deal

It certainly does. This is my solution: Mount the unit inside a weatherproof box and attach it to a pole on yer chimney (or other high point). See http://www.aquamanta.co.za/pics/dscf0102s.jpg for a pic.
Power is also carried over the ethernet. Don't go longer than 30m or your voltdrop will be too high.

The antenna is a GSM triband from poynting: http://www.poynting.co.za/antennas/gsm.shtml OMNI-A0039 (R126 ex. VAT).
You may notice the OMNI-A0047. Don't bother, it costs around R2,600 ex. VAT - I think they're crazy.

Even though this antenna is only supposed to provide 1.5dBi gain, I found it to be about double that, even with the 3m of cable rolled up. I imagine if I trim that it will improve further.

Total gain for this rig (form having the UTD indoors, as high as possible), a whopping 25dBi!
Total cost, approx. R700 - the most expensive bit is the pigtail, R280 ex. VAT from miro.co.za.

I refuse to use the Yagi antenna because in my mind, that defeats the purpose of iBurst being able to switch from one tower to another. You'll battle to aim it accurately anyway.

I'm working on a prototype omni colinear antenna which will provide approx. 7-8dBi gain - will let y'all know when I'm done.