# Mussels makes some crappy wifi cantennas!

#### jsfitz54

Question: with regards to the tv issue I brought up previously, with a picture mount, could a narrow parabola shield behind the tv (lined up with the internal adapter) help gain reception?

Samsung: http://www.amazon.com/dp/B0078LN0K6/?tag=tec06d-20

Would I be wasting time trying due to such a narrow curve? (math not right)

I think the repeater would be the solid way to go but in theme of trying to do more with less, what do you think?

#### Mussels

##### Moderprator
Staff member
ok so all this math stuff is new to me. explain whta you mean about the distance/size of the parabola properly and i'll test it out.

#### mlee49

Question: with regards to the tv issue I brought up previously, with a picture mount, could a narrow parabola shield behind the tv (lined up with the internal adapter) help gain reception?

I think the repeater would be the solid way to go but in theme of trying to do more with less, what do you think?
A standard backplane can increase the gain by as much as Half the power or 3 dB. Your parabola might help direct the internal antenna's reception towards the router, but the difficult part is isolating the internal antenna.

You might get away with changing out one of the antennas on the router to a directional one and pointing it at the TV for a better connection.

ok so all this math stuff is new to me. explain whta you mean about the distance/size of the parabola properly and i'll test it out.
Here's one that is easy enough:

http://www.freeantennas.com/projects/template2/

http://www.freeantennas.com/projects/template/

More on the Parabola: http://mathworld.wolfram.com/Parabola.html

http://en.wikipedia.org/wiki/Parabolic_reflector

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#### Steevo

The wavelength of the frequency should be the the distance to the phase center of the antenna from the reflective surface in a arc equidistant from said point.

Or, if the center of your antenna is the center of the circle the distance to the reflector should be equal to the wavelength of the frequency used to reflect and create a focal point of energy in the antenna. Much like using a parabola to light something with sunlight by focusing a larger cross section of the energy radiated by the WAP you will increase signal level.

#### Mussels

##### Moderprator
Staff member
The wavelength of the frequency should be the the distance to the phase center of the antenna from the reflective surface in a arc equidistant from said point.

Or, if the center of your antenna is the center of the circle the distance to the reflector should be equal to the wavelength of the frequency used to reflect and create a focal point of energy in the antenna. Much like using a parabola to light something with sunlight by focusing a larger cross section of the energy radiated by the WAP you will increase signal level.
stop speaking alien.

#### Steevo

Cut 10.2 inches of aluminum foil. Tape the ends to a piece of paper. Cut two or four bamboo skewers to 5.1 inches, less half the thickness of the antenna. Tape or glue the skewers to the antenna and the corners of the foil on the paper so that it forms a half circle.

#### jsfitz54

A standard backplane can increase the gain by as much as Half the power or 3 dB. Your parabola might help direct the internal antenna's reception towards the router, but the difficult part is isolating the internal antenna.

You might get away with changing out one of the antennas on the router to a directional one and pointing it at the TV for a better connection.
The new router was able to provide signal to the tv (for the first time) when it was stand mounted approx. 2 feet from the wall. When picture mounted, slightly higher, it lost signal.

Router: ASUS RT-AC66U

Room has always been an issue. I changed the Tx power from stock 80mW (no reception) to 175mW on both bands (worked while stand mounted). Max is 200mW.

Also changed stock 5dbi antennas for 9dbi ones.

I assume the wireless adapter is located on the logic board of the tv but am not sure.

#### mlee49

Most likely, so it sounds like the antenna on the TV is just getting grounded by the wall.

Is there any room to move it away from the wall? Even 5 inches could help at 2.4GHz.

#### Ahhzz

you're gunna need a bigger wifi dongle.
that's what she said.....

what?! Someone had to say it....

#### jsfitz54

Most likely, so it sounds like the antenna on the TV is just getting grounded by the wall.

Is there any room to move it away from the wall? Even 5 inches could help at 2.4GHz.
A change of TV mount might work. Will have to try when he is home (abroad currently). Thanks for the tips.

The picture mount I gave my friend was almost free. A bad bait and switch from an Amazon seller that I lost the mailing cost on(had to fight for refund of purchase price).
Bad taste in my mouth so I gave it away.

#### FreedomEclipse

##### ~Technological Technocrat~
I made my own 'parabolic' out of some old cardboard packaging from Amazon, all i needed was tin foil and some tape. sadly I didnt obtain the results that I wanted. It didnt make the signal any stronger and ive positioned it right behind the antenna's on my AmpedWireless repeater. I'll probably play about with the positioning a little more and see if it helps..

#### remixedcat

Really AMPED WIRELESS!!!!!!!!!!!!!!!!!!!!!!!!!

#### Geofrancis

I have used and abused every piece of wifi hardware out there for research into building a wireless isp. when i first started my quest i built a 1 mile wifi connection between me and a friends house. this was back when very few people had wifi so there was very little interference from other routers so with just a pair of routers with ddwrt @ 100mw and some cheap Chinese 14dbi panel antennas i was able to get a stable 2mb connection. this lasted for about 6 months before the speed started dipping to 1mb during the day then cutting out intermittently due to the popularity of wireless routers the noise leval was just going up and up until it was unusable. then i started playing with the cheap 1W 2.4ghz bidirectional amplifier. it helped slightly but it had the problem of amplifying interference so it still dropped out now and again. then i started looking into the ubiquiti 5ghz 300mbit routers(nanostation, Bullet, RocketM5). these things are amazing 100mbit stable at over a mile! and also has a built in RF spectrum analyzer for finding interference.
the wifi adapters i have used for testing long range setups are the Alfa 500mw usb adapter, ubiquiti Airstation 1W usb and my laptop currently has a 400mw PCIe Ubiquiti SR-71E so anything my laptop can pick up i can connect to. i want to build this

i bet i get funny looks getting the bus with it.....

#### mlee49

This is what you need:

Staff member

#### a_ump

didn't feel like going through 4 pages so here's mah question.

I have wifi but my router/modem is on one side of my house and my room is completely on the other side of it. I get enough internet for my laptop to pick up 1 or 2 bars, but my smartphone struggles to keep connected to my network.

Would building one of those design idea's behind my router/modem's antenna help the signal? Since its an omni-directional antenna i thought maybe putting a metal shroud between the Ant and the wall would help bounce the signal more towards my side of the house

#### mlee49

didn't feel like going through 4 pages so here's mah question.

I have wifi but my router/modem is on one side of my house and my room is completely on the other side of it. I get enough internet for my laptop to pick up 1 or 2 bars, but my smartphone struggles to keep connected to my network.

Would building one of those design idea's behind my router/modem's antenna help the signal? Since its an omni-directional antenna i thought maybe putting a metal shroud between the Ant and the wall would help bounce the signal more towards my side of the house
Yes, directing the antenna(s) will help. I posted a couple links on simple ways to create a 'reflector' on omni-directional antennas.

The wavelength of the frequency should be the the distance to the phase center of the antenna from the reflective surface in a arc equidistant from said point.
stop speaking alien.

wavelength = the speed of light / (2.4 gigahertz) = 12.4913524 centimeters

If frequency is 2.4 GHz, best results are when receiver is at focal point of a curved reflective surface which focal distance is 12.4913524 centimeters.

... if I remember alien math correctly

#### FreedomEclipse

##### ~Technological Technocrat~
Speaking of dodgy ass antenna's I had a bit of extra money to throw around and i purchased

and

for shits and giggles testing with my AmpedWireless SR1000

I also picked up a really really cheap small yagi antenna off ebay but that was just beyond terrible.

I have to say that the flat panel antenna is definitely serving me better the the long omni one.

#### Geofrancis

Speaking of dodgy ass antenna's I had a bit of extra money to throw around and i purchased

and

for shits and giggles testing with my AmpedWireless SR1000

I also picked up a really really cheap small yagi antenna off ebay but that was just beyond terrible.

I have to say that the flat panel antenna is definitely serving me better the the long omni one.

That tp link omni is a nice antenna I have one Hooked to a 1w ubiquiti Bullet2HP on the top of a block of flats and I can connect with my iphone 1/4 mile every direction. But the problem with it is it also gets interference from every direction so it's not ideal for urban environments. I'm going to me moving to a pair of mimo radios with diversity and 2 antennas each to try and get around the problem.

#### FreedomEclipse

##### ~Technological Technocrat~
The problem is - If i stick the omni on a long pole outside my garden - people will get suspicious of what im doing lol. I dont think the police here take unauthorised wireless network usage seriously here but it will still turn some heads if people see it sticking out of the ground - Its always about being discreet to avoid attention.

I'll definitely have a little fun with it though.