Homemade Laptop Wi-Fi Amplifier Review

<!-- Generated by XStandard version 1.7.1.0 on 2006-11-13T21:54:04 -->

Amplifying your laptop Wi-Fi

I have always been frustrated with the performance of my laptop Wi-Fi. I tried many solutions to improve the signal from far away routers, but few of these worked. I'll cover a solution that I came up with that finally did yield some results for me.

Most laptops nowadays have a mini PCI Wi-Fi card hooked to an antenna which is located inside a screen plastic cover on the laptop. I was browsing eBay recently and noticed that there were some Wi-Fi amplifiers available that promoted themselves as improving the reception of the signal. Sadly most of those amplifiers are designed to be hooked to a PCMCIA type card or a router! None of them seemed to be specifically made for a mini PCI card.

I decided to buy a Wi-Fi amplifier and hook it to my laptop. I have an ASUS A2H laptop with a Dell 1470 a/b/g Wi-Fi mini PCI card inside, I bought the card for $20 off of eBay. I bought the amplifier for $118, it is a 500 mw bi-directional amplifier called &quot;turbo tenna&quot;, the amplifier was shipped from Hong Kong and I received it shortly after ordering on eBay.

The Wi-Fi Amplifier, &quot;Turbo-Tenna&quot;, purchased from eBay (view large image)

The Design:

The first problem I faced with my Wi-Fi card were the connectors, they are so small and very difficult to connect to a plug, buying a special connector for the card would have cost me another $15 plus shipping, so I decided to solder the cable directly to the card. One of the best features of the Dell 1470 is that you can select the antenna plug you would like to use -- main or aux, so I selected the main and I soldered the cable to it.

The second problem was power supply! As usual, if you have a mother board the best power supply you can get is from a USB port. I needed 6v, and the USB was giving me 5v -- close enough!

Power supply from USB (view large image)

The third problem was hooking the card to the amplifier. I had 2 options, I could either take off the circuit of the amplifier and find a place for it in the laptop, which is a nice idea, or I can find a way to hook it externally. Though I wanted to put the amplifier inside the laptop, I decided not to do that for the following reasons:

1. I wanted more liberty hooking any antenna I wanted to the amplifier.
2. It is very difficult to find a place for the amplifier inside the laptop without affecting other components.
3. Heat issues! Those amplifiers produce heat and they are not supplied with an adequate heat dispenser.
4. The amplifier was expensive ($118) and I wanted to preserve it.

I decided to hook the amplifier through the VGA monitor out port! Why? First reason, the port is strong and can hold the weight of the amplifier, plus it comes with screw holes.

The VGA plug and Wi-Fi antenna cable (view large image)

Secondly, the VGA port comes with a few pins that are unassigned, sometimes they are soldered to the ground, and in some cases they are simply soldered to nothing. So it was a matter of testing those certain pins to see if they were connected to anything else on the mother board. After testing the pins I found out that pins # 9 and #11 were free, so I used #9 for the power supply and #11 for the antenna cable from the Wi-Fi card. I used the ground for the VGA for as a common ground for the power and antenna cable.

Wires in the VGA plug (view large image)

Wires to the VGA on board (view large image)

One thing I should mention, I am a switch freak, the more knobs on the machine the happier I am. I placed a switch inside the laptop that switches all the wirings between &quot;normal&quot; and &quot;amplifier on&quot;. I have tried many Wi-Fi antennas, the &quot;spider&quot; antenna is effective but doesn't offer high gain, while the so called &quot;russian&quot; antenna gives you more gain, but it is a bit bulky. I have used the russian style antenna in this experiment.

Spider and Russian antenna examples (view large image)

Amplifier hooked to the laptop (view large image)

Testing:

Using &quot;Network stumbler&quot; as a testing software, here are the comparsions between normal and amplifier on:

Normal:

The signal is weak and intermittent, it doesn't even reach -90 dBm, which is very weak. If I get lucky, the connection is usually 1Mbps with signal strength 0-1% and sometimes no connectivity (I guess you understand my frustration). Very few signals are detected, and sometimes nothing at all.

Weak signal

Amplifier ON:

A dramatic increase in signal strength! More than -80dBm, and the speed of the connection is 24Mbps with signal strength 34% as compared to the same connection at 1% previously tested. You can also see more Wi-Fi connections around you, though of course they're all password protected.

Stronger signal

 

Signal difference chart (view large image)

Pros:

• You are never disconnected wherever you go!
• Very light and attractively built, adds style and performance to your laptop (it is fun to see other poeple looking at it and wondering what the hell is hooked to the VGA port!)
• Very mobile and removable modification.

Cons:

• Radiation, I believe this thing produces the same amount of radiation that a cell phone produces, so try not keep it on too much, especially when you don't need it.
• Power consumption! It drains your laptop battery.
• Interferes with the back of the display, unless the VGA port is on the side.
• Requires an internal modification to be used on the VGA port, the VGA port might cause probems if hooked to a monitor that uses the unassigned pins (very small likelyhood though, the switch I made saves the situation).
• Can't use VGA port and Wi-Fi amplifier in the same time.
• Don't do such modifications if you don't have the knowledge and experience...and guts.
• Every country has regulations, be careful not to break the rules when hooking such a powerful thing to a Wi-Fi card.
• Amplifier company says: &quot;Don't exceed 50 mW to the input power of the pen booster&quot;, so if your card has higher capacity then it might damage the amplifier!

Related Reviews:

Super Cantenna Review -- Extend Your Wi-Fi Range

 

Nice review, though most people will shrudder at the thought of opening their electronics!

But wow, what a difference...

 

Wow, that's one gutsy modification. Nice work there and clever job doing that. I think I'll just stay close to my router and not worry too much about modding my laptop in this way though -- I'd be sure to electricute myself or fry the laptop.

 

Hats off to you, Red Scorpion! That took some creativity, ingenuity, and more than anything--guts! Now all you need to do is get one of those 20" notebooks and do this mod with bunny-ear antennae .

 

Thank you guys, I am planing to buy a MacBook Pro soon in order to replace my old Asus A2H, I heard that the MacBook is a bit weak in wifi, so I if I find a cheap one and buy it, I will have the WI-FI amplifier built-in.

 

GJ Red Scorpian, loved the review, your workmanship is amazing!

I do have some questions and comments.

1) Can you make one for the USB port instead of the VGA port?

2) Does the antenna draw a lot of power, hence you needed to use the VGA port over a USB port?

3) How much battery life did you loose due to turning the amp on? Can you measure the difference and lets us know please?

Comments:

Awsome job, I live in Toronto too! , and BTW, I heard the opposite about the MBP, I believe they use an Atheros card in which you get the best wireless connectivity with it.

Thanks for sharing!

MysticGolem

 

Nicely done Red Scorpion!

 

Great engineering! Great ideas and good results. I have no such problems, but this is one of the best solutions I have heard. Thanks.

Ivan

 

I was using a usb for the amplifier with a pcmcia card at first, but when you need to hook it to a mini pci wi-fi card, you need a cable from the card to the amp... and this is the only way that won't damage the cosmetics of the laptop. I could have drilled a hole and made the wi-fi cable come out of it, but using the vga port unassigned pin was much better!

As for question#2, my laptop consumes a lot of power anyways... it has a p4 desktop processor, and usually it lasts without an amplifier for 1:30 hours, with the amplifier hooked it lasted for 50 min I think.

You must understand that I only used the vga as a holder and connector, the power supply was from the usb but internally.

Actually the MacBook Pro is weak in comparsion to other notebooks, I heard it from many poeple over here, I think the main reason is the aluminium cover that kind of isolates the signal from the antenna under the screen cover!
I saw once an article about someone who drilled the battery cover of his Macbook Pro and used a wire to connect the wi-fi card to an external antenna, An effective but ugly solution. What I would do if I was to buy a MacBook is to use one unassigned pin in a port for an external removable antenna instead of drilling the thing and destroying its cosmetics.

Thanx, I like your questions... they are logical and smart, I am ready to answer any other questions anyone has.

Cheers~

 

say,

you mentioned about radiation... I got that same antena for my router, and I sit by close with my laptop so...I must be dying earlier...

 

The joy of custom mods . Nicely done.

 

I red somewhere about wifi cards that consume 400 mW power like the senao EMP-8602(tried it and was a bit disappointed) and the Ubiquiti SR2, they posted a warning about radiation, there is even some cards that consume 700 mW like the Ubiquiti SR9(this is a big bazooka) lol
This amplifier is consuming 500 mW! so I guess it is not very good to be closer than 20 cm to it.

Think about cell phones, they cause a cumulative injury to the live tissues and the more you are far and less exposed... the better!

Not to worry too much, the radiation decreases in a logarithmic curve with distance, I guess 20 cm is ok.

 

Thank you for your answers, wow, this is an interesting thing.

So the amplifier definately eats the battery, i would imagine it can eat up to 45 minutes on a laptop that last 3+ hours or so.

It would be interesting if this device can be made into something as small as a USB be dongle, if that's possible.

Other than that this device is close to $150, yikes! You also mentioned in the original post, that there are 2 types of items that can boost WIFI connectivity, ones that connect to a router, and ones that connect to a laptop (or ports in a laptop).

Do you know of any small devices that would do the same as your home made amp? That would connect to either the laptop or the router?

Thanks,

MysticGolem

 

Impressive.. most impressive. But for those less willing to challenge themselves to opening up their notebooks - here's an alternative for the mBp crowd:

http://www.quickertek.com/5dBi_Ant_MBPro15.php

 

You are talking about buying an amplifier with a PCMCIA card hooked to it, in that case you don't need any modification, but it is not as mobile... too many connections, and the amp will come with its own power supply.

 

My friend, this is what I call disfiguring the laptop, what you didn't see in the picture is the hole in the battery cover in order to pass a wifi cable to the antenna.

They say in the page that you have to send the laptop to them so they can drill it "professionally", I would say taking the laptop to a dentist is better... he would drill a better smaller hole which could be more cosmetically acceptable

 

I must chime in and say that while boosting power seems like the best way to improve things, it's always secondary to better antenna tecniques... Besides being totally illegal, power boosting has other issues...

for instance, when you are powered up you are jamming your neighbors due to the overlapping 2.4ghz spectrum.... the astonishing power requirements... possible EMI issues... and possible issues with getting too close and having it not work due to front-end overloading in the receiver...

A 10db increase in signal level would have been accomplished by a $20 panel antenna at the router, or possibly a better router.

im a party pooper, I know. Sorry.

 

You are right, methodical

I never denied the issues you mentioned.

But the peoblem here is increasing the signal on your laptop(and staying mobile), I was not talking about increasing the range of a router.

I just find this modification as a practical solution for the laptop when the signal is very weak and you need it. You don't have to use the amplifier when things are ok.

Putting a turbo system on a mini car is not practical in most cases, but if there is an emergency, the turbo system will get you to the hospital and help gain critical seconds in the ER... (if you don't get an accident on the way lol)... besides the fun of it!

 

Cool! Im the type, who needs the minimalistic view, all the switches and technical stuff should be well hidden, The only thing the user(me) has to see, is the interface. So lately I included my mouse reciever in my not-so-cheap subnotebook. Although keeping all the functionality of the pci express slot(if needed).
I really like this kind of topic, but not many people have the guts to open their pcs and weld something in there...
Well, nice work. bye

adding a link: http://forum.notebookreview.com/showthread.php?t=62809&page=3

I forgot: Im planning on adding a webcamera into the lid, Im just looking for a suitable device...like an orbicam, which is used in acer notebooks or similar. So if anybody has a clue, please pm me. Thanks a lot

 

Good work, laser21

Actually I was thinking of doing the same modification on my laptop, the asus A2H has 5 USB!

There are some mini USB webcams in the market that are suitable for the job, like the Sweex USB Mini Webcam, or the FlexCam mini web cam.

Problems you might face:
-Finding enough space for the webcam in the screen cover.
-Passing the cable to the screen (internally).
-Sacrificing another USB port for the job.

You can get a usb replicator for 10$ and place it in the laptop, I have seen some very compact ones!

 

I just want to point out that using a VGA connector for 2.4 ghz RF is a REALLY REALLY bad idea.

You could be loosing a lot (perhaps most) of your signal through it.

There is a reason the antennas use unusual threaded connectors. Energy behaves very strangely at high frequency, and things that are normally good conductors start to behave like inductors and caps.

Try running the antenna straight to the WiFi card, and see how the signal improves.

Incidentially, your "Spider" antenna is actually a 5/8 wave ground plane antenna. the "Russian" antenna looks to be an unusual Dipole with a couple of center loads.

Also, 500mw rf output does not mean 500 mw power consumption. In all likelihood, the amplifier is probably drawing a few amps. Do NOT connect one to the USB port. You probably wound up connecting it to the laptops internal +5v rail. Energy-consumption-wise, it's probably drawing a few tens of watts (or more).

The rf amp project is the kind of project where you should DEFINITELY do a little research about rf engineering before just jumping in headfirst. Up above a few hundred mhz, electricity becomes completely counterintuive, and behaves very differently.

 

Fake_Name, You seem to know pretty mush about antennas and radio signals... thank you for your remarks.

They usually call it spider antenna for the fun of it, as for the russian antenna, I have to confess here about something!

The story of the antenna I made is actually an experimanetal modification of a "sector antenna" aka Russian or serbian antenna!

If you understand Francais, then read this:
http://www.brest-wireless.net/wiki/materiel:amos
It had another arm which is a replica of the arm showing in the picture, I was hooking it to a PCMCIA card (buffalo high power), I wanted an omnidirectional antenna because I don't like to aim the antenna to a router when I don't know where the router is!
So I got ride of the reflector. The results were not very different (1-2%)!
Then I rotated the two identical arms of the antenna in a V shape, and the results were even better!... In the end I removed one of the arms and the results were still as good!
The science of signal reception and antenna design is very complicated and amazing, especially digital emulation.
I can understand some stuff, but I am not a professional, it is just a hobby for me, in that situation experimenting and result is option #2!

Regarding the RF lose when passing throgh VGA, used coxial cables wherever I could, I mentioned before that I don't like to drill holes in my laptop for the sake of having a wire hooked to an external WI-FI amplifier, I believe there isn't much lose... maybe 1-2% big deal!

You might be right about the usb power supply, but I don't have a plan of the A2h motherboard to find a direct 5V source , and I would rather connect the amp to the 5V of the USB connector which is REGULATED.
As for the battery duration, I guess the drain estimation is not very accurate, my batteries are old anyways and they give a different duration everytime I use them... but still the amp consumes power, I noticed that.

I wanted something mobile and removable theat doesn't affect the cosmetics of the laptop.
If you have any suggestions to improve the project please post them.

Sam~

 

Could you please post some english links to the Russian Antenna

 

I am sorry, I don't know about english explanation...

Try to use google bar and translate the page!

 

Maybe this link will help, it was posted in the same french page! no explanation but the pics pretty much say everything!

http://www.qsl.net/yu1aw/vhf_ant.htm


"A picture is worth a thousand words" Napoleon Bonapart

 

Excellent work! Very slick design.

How did you go about making the hookup to the mini-PCI card? I've been very curious to try an external antenna (without amplifiers, just higher-gain antennae) but don't have a wireless NIC with external connector. How did you know where to hook in to the card itself? Was that unique for an amplifier, or just any external antenna?

Thanks again!

 

Choose the main connector, not the aux, and try to find out if there is a way to select the antenna connector on the card properties in device manager.

As I said before, you can either solder the coxial cable to the card directly and lose the chance to connect it to a normal connector again! (which I did)... look at attached picture!

Or you can buy a U.FL plug with its wire and hook it to the mini PCI connector onboard... look at the second attached picture.


dman those plugs and connectors... they are very difficult to handle.

 

Being the amp is a no-name chinese make I would imagine the only reason it hasn't fried your USB power is because its not really 500mw. Like most no-names its probably overstated and closer to 75-100mw.
If it were a true 500mw your USB would be complaining of to much power demand. Most USB ports are only rated for 500ma at 5v (2.5watts) max. Anything above, and the port will complain and disable power.
Typical 500mw 2.4ghz amps require at least 5-6watts and in a few cases I've seen some down near 4.2watts.

btw.. I'll take a well placed hole an petite connector any day over having to lug extra stuff.

 

It's very probably it's a good deal more than 1-2%

For the sake of experimentation, try avoiding the vga connector by just leaving the bottom panel of the laptop loose so you can just run the wire out.


Another side effect of using the VGA port is that you're probably radiating quite a bit of energy from the exposed wiring.

Also, the impedance mismatch caused by the connector could possibly damage your Wifi card. It's not likely, but it is possible.

Lookup SWR (Standing wave ratio) on wikipedia for waaaay to much math about antennae. Google might be useful too.

 

Thanx for the info. My guess... probably having that thing internal would be the high yield solution!
But I want to sell my laptop soon and I don't want to sell the amplifier with it.

 

An artist...really...an electronic artist…
I got one question: how did you configure the VGA port so that the card could recognize it.
i was thinking of connecting the same way on the VGA an external home made (myself ) yagi antenna, so could you please explain how did you configure it. i guess it would be an analogy for a usb connection aswell.

thanks

 

This thread makes me want to catapult myself into the world of electromagnetism, or else haphazardly start soldering things. Cool mod, and interesting posts saying why it's a dangerous mod. We should have more of these kinds of threads.

 

Congrats on making such an awesome modification!

I'd be waaaaay to nervous to do that myself..

 

gogo gadget antenna!

 

@ Diktator
I didn't configure the VGA Port, if you check the article again, you will notice I mentioned that VGA ports usually have 3-4 pins that have no function or contact to any component, I used those (after checking and comparing to schemes available to the port) to pass the antenna cable to the outside. As for the amplifier, it is not a card, it is simply an amplifier that connects to the internal card and is hooked to an antenna.

Cheers~

Sam

 

Cool. BUT, that is absolutely hideous, I don't see anyone using something like that. It is like dorkman 5000. You'll look like McGuyver.