How not to make a WLAN-antenna

This is a re-edit of my first 'Ible. Since I am now older and wiser and the comments are really useful I'm making this an anti-instructable.

Step 1 Don't do it like this ..

I originally tried to improve the existing antenna .. it broke. These are the pieces.

Comments

[Shadetree Engineer]

Well, we can either calculate the most efficient design using the least amount of materials, or do it the long-wire way. This would appear to be a form of 'long-wire' antenna, where the radiating element has multiple wavelengths. This can work very well if you ignore the extra loading on the transmitter from a mismatched antenna. It's all about getting a connection, and if you have a notable improvement in your net surfing, then don't worry. You could try using one of those rabbit ear antenna's from an older tv set. That would give your rig a retro classy look.

[WIFIENGINEER]

Ok this is kinda scary

You havn't made anything even close to being resonant and the only thing keeping the router from being burned up is that it has so little power.

The lesson here is NEVER try and "improve" on a factory antenna.

[m3lvm]

I must express some concerns as to what one is doing by placing a large length of cable on the end of your wifi sma socket.
You are dealing with a radio transmitter between 2400-2500 MHz. I must stress that it is important no matter what frequency us use in the radio frequency spectrum the antenna is tuned to the frequency you wish to use!!!!
There are three types of antenna that one can use dipole, vertical or beam (yargi). If we look at the antenna thats provided with your wifi its a classes a vertical and in this case its most probably a quarter wave antenna. There are four type of vertical antenna you can have quarter wave, half wave, seven eights wave and full wave. So if you want an antenna for your wifi you must calculate the length of the antenna mid frequency 2450 MHz of the wifi range E.g for a seventh eights antenna the length of the vertical would be 4 inches and 1 thirty second. I have added a link to a calculator and if you scan ham radio sites you will find many ways of building different antennas.N3NO's

[omnibot]

Very true.

[waterppk]

Yeah, your primary problem with this system is that your antenna isn't just where you strip the wire, it's the whole length of the cable! So you actually made an antenna tuned to really really low frequencies because it's so long! The wireless spectrum waveform is about 4.84 inches long, so your antenna you pulled apart and broke is a 1/4 wave antenna, at exactly 1.21 inches (which is what you want).

[omnibot]

Yep. It sucked alright. But it worked for that night.

[Body4Change.com]

I've been reading a LOT of this WiFi stuff here on our extraordinary Instructables.com and was wondering if anyone has tested the strainer method against the coffee can or pringles method and also against using an old directv satellite and such. Which one would give me the best reception? I'm guessing the satellite dish but I am new to this. TIA!

[omnibot]

I agree with previous posters .. this is a bad idea in the long term. For something lasting and much more elegant this should prolly not be a permanent solution. In my defence this was my first instructable, it was 2 in the morning, the wifi was driving me crazy and it worked ;v) I'm already replacing it with a nicer doodah.

[bleachworthy]

ok, so this is what I use to get my wifi out to my gazebo http://www.freeantennas.com/projects/template2/index.html it's a parabolic reflector, you place on the antenna, it boosted my signal by (get this) 9 DECIBELS!! that's an AMAZING ammount for being constructed out of paper, and tin foil. I highly advise it. (btw, this is a uni-directional antenna)

[wombat7]

if you have a usb port this may be easier

[zm634]

Agree with bleachworthy. Antennas (especially wifi) are meticulously designed to maximize efficiency and minimize space. On radio receiver box, "Do not modify antenna length as this will degrade performance." Cantenna FTW.

[bleachworthy]

Wow, dude. umm, that antenna is so puney for a reason. the material, and gage of the wire used, is ENGINERED to be that small, because it is made to recieve 2.4 ghz signals at maximum efficiency. if you're going to mod an antenna, to make it get a signal where you KNOW where it's located, build a cantenna! I'm really surprised you got any signal at all with that giant clumsy cat5 cable wire. also, another trick I've done with my laptop is, I added a pigtail, exactly like the one you yanked, and replaced one of the 2 antennas mounted in the screen's frame. it boosted my reception by about 75% (as in I now get 175% worth of performance) Now, other than the extreme design flaws, it's a nice instructable. lots of pics, that's what makes a good instructable, along with descriptive text, I think.

[omnibot]

A word of caution before someone else says it : It's possible this could do harm to the computer or something and it's not the most elegant sollution but it sure beats getting some expensive pice of rubber.