Picture of Unleash the Power of Your Router!

In this Instructable, we will be adding fans, a heatsink, and 9dB antenna to the LINKSYS WRT54G series router for use with DD-WRT firmware upgrade!
These routers are…well…awesome.
Before we begin I wanted to provide a rundown on the router to spark your interest, especially if you’ve never caught wind of its awesomeness! J
They have been implemented in more scenarios than almost any other router on the market due to cost, ease of use, and potential abilities. With the GL being Newegg.com ‘s number one selling wireless router as well as on the sites Top Ten sold of ALL products (as of today 5/10/2010) and the GS reported in New York Times Online Top 10 Most Popular Routers worldwide(as of today 5/10/2010) , you cannot go wrong with this little wolf in sheep’s clothing.
The $50 WRT54G with DD-WRT firmware in a parabolic dish setup helped to set the 2nd place world record for unamplified Wi-Fi distance in Venezuela @ 173miles!!!! Second only to the $100 XR5 on a $190 PCEngine WRAP board at 189miles in Italy. Recap here Long Range Wi-Fi Wiki
Most versions of this router have the ability to upgrade its firmware to an open-source Linux build called DD-WRT downloadable from DD-WRT (free). If you decide to upgrade to a firmware on this site, PLEASE read ALL the directions, FAQ, Wiki and Forum EXTREMELY THUROUGHLY, as improper firmware flashing can leave you with a very expensive paperweight. I cannot stress this enough! You have been warned!
With a (somewhat) simple upgrade to the appropriate firmware, this $40 - $60 router can save you hundreds of dollars and open up a seemingly endless amount of capabilities (and void the warranty). Chances are though, if you’re confident in performing these upgrades, you couldn’t give a darn about warranties. You’ve already voided more of them than you care to keep track of. AmIright?
The purpose of upgrading this router is so that we can safely use the "DD-WRT" firmware "Overclocking" and "Increased Transmit" functions to their max without having to worry about overheating issues!
Note: I’ve heard several people arguing that adding heatsinks is not necessary; that they have maxed theirs out without any problems. I have personally burned out 2 of these units, and had serious stability issues in others due to overheating by maxing out without extra heatsinks at the very least. Please refrain from filling the comments section with “You don’t need heatsinks or fans” comments or the likes. If you don’t want to install them, keep it to yourself. Thank you! J
This type of upgrade is most useful in very large households, businesses, neighborhood-Wi-Fi, trailer parks, RV parks, campsites, etc.
With this one I’ll be using it for an ad-supported neighborhood Wi-Fi which provides both an internet source for people who cannot afford it, but also a way to reduce costs for the person who pays for the source connection- usually high speed cable service that a single household will never fully utilize; unless you have a pirate in the midst. (YaaarRrRR, I cannot condone piracy, mateys!)
In this Instructable I will not be covering flashing the router with DD-WRT, nor will I covering its configuration. That is one thing that is far too router specific for me to want to post. You can however find out all the information you need at the DD-WRT website.

Do NOT buy antenna on ebay!
I have personally purchased a pair of "9dB Antenna" from a VERY reputable seller. They did not reach anywhere near 9dB. If you follow this instructable and use antenna you got from ebay, don't complain when it
doesnt work.
Having said everything I wanted to get out of the way: I hope you and all the wonderful Instructable enthusiasts enjoy this Instructable!
Comments, suggestions and questions are highly encouraged!
Without further ado, lets mod!

beej20015 years ago
I modded my router quite similar to yours. Heatsinks on all the chips, and a small fan inside the case. I drilled all the holes top and bottom bigger, and called it good.

It sat outside on my balcony for an entire Las Vegas summer with temps over 110 with no problems.

oh, and I painted my case yellow
NostalgicStone (author)  beej20015 years ago
 Very cool man!
I like the color, reminds me of  Bumblebee!
One thing I haven't done is drill the holes larger on the bottom
(seeing as I how I no longer have holes on the top lol)
I love it
SamuelA111 months ago

guys does it upgrade the wr641g

Are you British? I absolutely love your wits all throughout this instructable...it makes it quite the enjoyable read.
Here is a picture of the router mounted on the fan.
Lol :D
Hahaha I love this
LOL!!!!! epic win :D
will this work?
imboox23 years ago
I see this has been out a long time. For anybody reading this now, there is non-corrosive solder flux available, there has been for many years. I have been in the electronics field nearly 40 years and have used it a long time. I use solder paste to keep the tip of my soldering iron clean besides keeping it tinned.
DustySeven73 years ago
You got some of your information wrong. The current unamplified record is 237
NostalgicStone (author)  DustySeven73 years ago
That's awesome! But I was referring to unamplified distance, hence the bold and underlined "unamplified" in the ible.
Read closly, it is unamplified. They used a dish reflector to shape the signal
hwally3 years ago
Great tutorial. I have a 12 volt 0.82 amp fan, would that work as far as not drawing to much power. I have a wrt54g router. Thanks
bowmaster4 years ago
what's the range on this? Could it be expanded to a mile?
NostalgicStone (author)  bowmaster4 years ago
Sure, if you use the right dish.
From 'Ible:

"The $50 WRT54G with DD-WRT firmware in a parabolic dish setup helped to set the 2nd place world record for unamplified Wi-Fi distance in Venezuela @ 173miles!!!! Second only to the $100 XR5 on a $190 PCEngine WRAP board at 189miles in Italy. Recap here Long Range Wi-Fi Wiki"
Cool. That means I won't need to know the wifi password at school, I can just use my home network.
NostalgicStone (author)  bowmaster4 years ago
While this is possible and would be pretty cool, there are many caveats you have to keep in mind. First is that when you are surfing on a wifi connection, you are both sending and receiving data. This means that your wifi card would not only have to pick up data, but be able to transmit it back to the source. Using a dish on BOTH ends would work, but you would be using directional, not omni-directional, and your "available network area" would be determined by the direction, and dimensions of said dish(s). You would have to point both dishes directly at its counterpoint receive/ transmit respectively. This would be quite a task and would mean that you could not move at all once the connection has been established, or you would have to re-calibrate your dish(s). If you decide to undertake the project in spite of the obstacles, make in Instructable!
Hmmm, good point. Surely if if can break 100miles with a dish, it could get over 1 mile with an omidirectional.
NostalgicStone (author)  bowmaster3 years ago
Possibly, if using a very powerful antenna and perhaps a signal booster but you must remember that the WIFI CARD that you are attempting to use (in the laptop) must ALSO be able to SEND the data back to the router. If you can get a wifi card to broadcast 1 mile, make an instructable! That would be quite a feat!
Hmmm, it might be possible to hack a USB wifi card to do it.
Barron1114 years ago
Great work here. Does that upgrade work on the WRT300N ?
Ale Cylon4 years ago
Hi, great guide dude. Can i ask how far OCed can it goes or how much TX power can it gets after the mod, I have my WRT54GS only with Linksys 7dbi antennas and for confrtability I use the stand on for the antenas with the 6 feet cable to place them in a better location.

I ahve only made the TX power go to 70 and clock still is on 216Mhz. How much can I go after such mod?. I was planing into only add a fan but if I can get much enough after the mod then i can try.

Thanks man.
Nice write up! One question, I have a whole tube of this stuff:


any reason why I can't use this?
pgentry4 years ago
Wow I live in Montana and I see your router on my list of network connections I think you just set the new record. I think I am going to set one of these up for every one who lives in my neighborhood I hope none of the kids grow extra didgets hay its says 2.4 right here on the side of the unit officer.
leeroper4 years ago
Nice one dude, people will have want they want, even if they can't buy it off the shelf haha!
kill-a-watt5 years ago
is this router still the best choice for the DD-WRT firmware?

Hasn't Linksys secretly reduced the amount of flash  and RAM without changing the part numbers, gone to non-removable antennas and still has the chutzpa to charge $50 each, near the same price as 5 years ago?

I'd expect them to at least put a SD card slot in the router by now.

I could really use something like this but I'd hate to encourage Linksys
I have an old PC running linux that meets all my household network needs, except if I could replace it with something that burns 30 watts less, 24/7, the break-even point for a $60 router is about a year and a half.
NostalgicStone (author)  kill-a-watt4 years ago
Excellent! Thanks for the stat.
When I mentioned that it could save you hundreds, I did not mean in electricity lol!
I should have added "in comparison to routers that come factory with these settings"
Goes to show how perception greatly varies depending on your previous experience/ interest/ needs etc.
Thanks for the post bud!
OK, I picked up a thrift store Actiontec MI424WR revC for $3.99. I probably paid too much as it didn't come with the power supply, but I have one. It's supported by dd-wrt. It boots up at a hefty 14 watts, but I'm still going to save 35 watts every hour , or 307 KWH per year (about $50)
NostalgicStone (author)  kill-a-watt4 years ago
Again, thanks for the post, but again, I am not referring to savings in electricity, and I've purchased a "bricked" WRT54G for as little as $1 that can be fixed for free, and generally speaking wardrivers power these via public power jacks, thus eliminating the need to worry about electrical costs period.
Thanks again!
NostalgicStone (author)  kill-a-watt5 years ago
I hear what yer preachin man.
If you don't want to support a company, but still like a certain product it makes/ used to make, EBAY!
I never buy new ones, theres no point.
You are correct, they have been nerfing their new routers like none other!
This router is still my personal favorite tho, and there are plenty of the old versions out on the market for close to the same price they originally sold for.
Hurray for modding!
papaduck5 years ago
Flux corrosive??????? Flux for metalwork and plumbing is but we're doing electronics not plumbing. Go to Radio Shack or even a good hardware store and get some rosin core solder made for electronics work; it's ugly if you don't clean the excess off but it won't rot your board.
it will attack the Wire and/or the solder join , ( i dont remember ).
NostalgicStone (author)  hitachi84 years ago
I do believe it's both :)
Thanks for posting!
NostalgicStone (author)  papaduck5 years ago
If you leave that "ugly" on for too long, or there is too much "ugly" the board will slowly deteriorate. I have personally had to re-issue board to companies because people in the company I worked for (I.E.C. Electronics, Newark, Ny) did not wash the flux off properly, and the boards cease to function do to deterioration. It is not terribly common but it does happen.
Thanks, I'm a retired bench tech but never had that happen. Good to know!
I have recently purchased a WRT54G-TM with the 9dB high gain antennas and I have already flashed it with DD-WRT and its running great. Sometime sooner or later I would like to do hardware mods like the glorious fans, but I'm at college and have no supplies to do it at the moment. For the time being I have a small heat sink on the CPU and I have mounted the router to my box fan in the window. The box fan makes the long antennas vibrate slightly, is this alright for the router and antennas or should I move it?
Ive been reading through the comments and i couldnt really pull out what the approximate range of wifi is on this thing or if the wifi can be recieved directly by like an ipod touch or laptop. Thanks
Hey, great Instructable, but I have a little question. Since wifi is a two way conversation, wouldent the person on the recieving end of this monster need a huge router as a network bridge? Because an average wifi card can't broadcast 198 miles or whatever this beast can do?
camp6ell5 years ago
so disappointing... i read the title and immediately thought of the new tricks i'd be able to perform on the router i have in my woodshop...
pfred2 camp6ell5 years ago
ha ha that's why I clicked on it too! I'm on my computer out in the garage now that I RJ-45 hardwired to my router in the living room. What is the big deal with drilling a hole into the foundation anyways? I mean really now, what are hammer drills for? That, and wireless sucks anyways. The wireless laptop connected to that router barely gets a quarter the speed hardwired machines get. lesson to learn, man up and just run a wire. Presently I am in the process of building myself a CNC machine for my router. I don't think it gets much trickier than that! I have my electronic sub-assemblies all finished, and am designing the machine frame now.
NostalgicStone (author)  pfred25 years ago
Clearly you enjoy tooting your know-how horn, but I suggest you read the whole post if you wish to learn why one would want to do this. It's not for home networks. Duh. I have other people paying my internet bills, and then some. Look into it. Thanks for stopping by!
@ NostalgicStone my post was in reply to camp6ell. Had I top posted to your article then it would have been to you, or about your project. But I didn't. Clearly you habitually co-opt signals. Next time I drive past a work release chain gang cleaning the side of the road I will think about you and give a little Toot-toot! Who knows, one of those brightly colored jumpsuited prisoners could be you? Don't feel bad if I don't stop though. Anyhow this is what a router looks like to me:
NostalgicStone (author)  pfred25 years ago
I have ok'd the whole thing with my ISP, so dont you fret a thing, but I appreciate the concern! I'm unsure what the photo is all about tho, as most people here were aware that you weren't referring to a networking router, but thanks anyways! Many people use wireless devices that they carry around like laptops, iPod touch, iPad, PDA's, netbooks, tweetmachines (ugh), psp's, etc. in which case hard wiring is not an option. I agree with you tho, if its a stationary machine that you don't carry around, then yea, take the initiative, save some money, utilize your full network bandwidth and just run a cable! Thank you for commenting!
First you say, "I have other people paying my internet bills," now you say, "I have ok'd the whole thing with my ISP". Which is it? I am leaning towards choice D, none of the above.

" I'm unsure what the photo is all about"
It is a picture of one of my routers. It has power to unleash. See?


NostalgicStone (author)  pfred25 years ago
Read the Instructable, and you will learn what it means when I say "I have other people paying my internet bills" because, in fact, I do. The users connecting do not pay me, but the advertising company whos ads are displayed on the users browsers, do. Also, my ISP is very aware of the situation, as I am paying for their 12mbps service with the expressed intent of rebroadcasting an ad-supported WiFi, and I have a case manager with full documentation of the entire situation prior to, and current with the set-up. All traffic is subject to filtering of sorts, and no illegal activity on the network is tolerated and blocked by mac address if and when detected. So actually it was C All of the above. Very nice router you have there! Lets be friends? : )
NostalgicStone (author)  camp6ell5 years ago
Lol! Sorry to disappoint! Thaqnks for stopping by!
desertdog5 years ago
Well done and excellently explained.
NostalgicStone (author)  desertdog5 years ago
Thanks bud!
hed4205 years ago
Hi, I want to repeat/bridge an open free signal in my neighborhood and was wondering which Linksys model I should get (WRT-G, GL, or GS) and what's the difference? How does a D-Link DIR-655 Xtreme N compare? Right now I have a small usb G adapter with a long usb extension cord attached to my laptop since my laptop's built in wireless card can't pick it up. I want to be able to log in anywhere throughout my house. I'm planning of attaching an old direct-tv sat as the antenna.
dtcmcc5 years ago
Awesome! Great job explaining & illustrating. Now, if I only knew how to solder, I might try this. This project might get me to learn! I enjoyed reading this. Simply awesome.
NostalgicStone (author)  dtcmcc5 years ago
Thanks buddy!
Check this out:
How To Solder!
Aaaaand GO!
stjeff05 years ago
My linksys came our perfect!!! You are the man Nostalgicstone. Thanks again.
NostalgicStone (author)  stjeff05 years ago
Hey thanks buddy! Post a pic!
NostalgicStone (author)  NostalgicStone5 years ago
Right on! So is the fan blowing down into the router? I ask because the filter is on top and would always suggest pointing the fans up, but thats just me :) Great pictures, congrats on your new heat-resistant more powerful cheapo-superrouter :P
stjeff0 stjeff05 years ago
OK...Here is a pic, but nooooo laughing. I had found some extra material that would make a good filter, so this is "Linksys Lady O'"...if your familiar with her pill box hat, you'll know why. I burned this same exact router up and found this one at a thrift store for $3,99, as a back up. I wanted to make sure that it had plenty of ventilation to last longer. I share my connections with a few people in this complex ( they all pay rent for the use), so I can't have paying people cranky. Since I doubled the standard power, I had to put a heat sink on the main chip. I didn't have any thermal paste, so we went with tooth paste... GRAND TOTAL=3.99 Now everyone's signal is perfect, and I have been running it stable for over a week. Thanks again Nostalgicstone.
sayton5 years ago
Thanks for this, great post, I have a WRT54G v8 so I am going to have to add the attennas :(.  A couple things I though of while reading this thread. I think while doing this part, it would be a perfect time to make it POE; right off of one of the Ethernet ports.  That way this could be stashed some where with out power. I also feel it would be better to use a solid wire; like a nice lucent silver solid 22g and terminate with two fan plugs.  It would be able to handle the voltage and would not be so cumbersome.  De-solder the power jack, make it POE, and then it would leave room for two fan plugs on board ;), with little work.  
Blackice5045 years ago

Hi i love the this brand as well i have a asus switch and a single port WAP54G access point my question is i have Some really Big External Antennea for Standard SMA Connectors but like your Linksys i have those TNC connectors but the compaired to the normal once you can get from the shop such as a convertor from TNC to SMA it does not fit because its like Linksys changed the TNC connect by putting the Male inner on the Female Connector and Vise versa so my question is Where do you get Convertor Connectors from or should i just replace some High Freq BNC connectors or SMA connectors?

NostalgicStone (author)  Blackice5045 years ago
I read over this like ten times, and I can't quite make out what you are asking..
I believe you are looking for a good place to find a TNC to SMA adapter?
If so, try here Digi-Key. They’ve got more adapters than I care to throw a stick at : ) 
Thats all well and good if you live in USA but i live in Australia and we do not have Digikey all the places i have looked to do have Adaptors TNC-

And just let you understand better its simple The Female Connector has a outer with a Screw like a CB UHF Radio Connector and on its Inside it has a Male Connector instead of a Female Connector like the Standard wich is Male PIN and male outer the Linksys Connectors are Mismatched and that is so you buy stuff from them.
NostalgicStone (author)  Blackice5045 years ago
 I sincerely apologize, but I have read it several times and do not know exactly how I can be of assistance for you.
I do not live in Australia, so I’m not exactly sure where you could go to purchase the materials required for your project :/
I suggest doing a little independent research and I'm sure you will be able to figure something out!
Perhaps you should replace the connectors on the board?
De-solder them from the mainboard and replace them with connectors that fit the requirements of your specific situation.
If you are not comfortable with de-soldering the components that do not meet your needs and replacing them with components that WILL meet your needs, then I do recommend that you do not attempt this mod in the first place! Much better to have a non modded router than a broken one!
Feel free to PM me if you would like to, and as always, thank you for your interest!
NostalgicStone (author)  User15 years ago
I did not mention the achieved overclocking because I didn’t want this to turn into a pseudoforum for DD-WRT, but since you asked, the v2-v3 go up to 300mhz, and the v4-v6 will go to 250mhz. The router used in this Instructable is no longer in my possession, but I believe it was a v3 which means its running at 300mhz.
Thank you for your support! 
elone12105 years ago
 Really great mind.
Braydenhord5 years ago
2 watts is the legal limit for personal antennae. And 1 watt can broadcast like redonkulously far...
Like, omg, your instructable is teh awesomeness and it pwns all others!! =D
More, post MORE!!
NostalgicStone (author)  stagnantpathos5 years ago
 Well hey, thank you very much!
I shall indeed post more very soon!
Zorink5 years ago
Excellent instructions!

Are there any hacked firmware variations for faster routers (like wireless N 100-300 Mbps)? If I understand this correctly, this will only boost the range, not the speed?

NostalgicStone (author)  Zorink5 years ago
I haven’t tried on any other routers, but there are tons!
Check this out: 
Compatible Routers List
The firmware upgrade unlocks a HUGE amounts of enhancements including overclocking (Speed) and TX rate (Transmit area). If your router bottlenecked before, DD-WRT could possibly provide the solution for you. 
Do some research!
DD-WRT HomePage 
Thanks for the links!
NostalgicStone (author)  Zorink5 years ago
 No problemo!
Tachyon5 years ago
Good job on this instructable. Well put together and lots of photos.

I just have a question and a few comments.
- Question: Why the heatsinks? 
   I have half a dozen of these running DD-WRT. Most used as WDS bridges using external antennas. I have not had any problems with them that I can relate to overheating. I think this is a common misconception about these routers. That they have heat related stability issues. If you have them in a reasonably well ventilated area without stacking things on them or putting them in a hot area (ie sun) then they should run pretty solid. In fact mine have run for months without a reboot.
-power issues. These units are however sensitive to unclean power and power spikes. If you plug them into a decent (ie APC) UPS that filters power they will run stable for months at a time.
- Antenna. For indoor use, upgrading both antenna's may make sense as dual antennas can overcome some indoor obstacle related issues. However in most cases, you only need to upgrade one antenna. This can not only save you the cost of two antennas, but you can put a little more into one really good antenna.
The unit normally operates in diversity mode which means it will only use the best signal from the two antenna ports anyway. Therefore two matching antennas are not necessary.
- TX power etc. I tested these units extensively before going production with them as WDS WAN bridges and I found that there was no benefit to monkeying with most of the default settings. For example, upping the TXpower setting didn't increase range but did increase error rates and caused heat/crashing. You're much better off upgrading the antenna than messing with the TXpower setting. 
- Clock speed. Same as with TXPower. You can increase the clock rate on some models, but why? It runs DD-WRT fine at the default speed and the trade-off is increased heat and instability. In fact I've had to use an icepack on the CPU to get one to boot long enough to set the clock speed back to factory as a minimal increase was instantly fatal. Causing the unit to not even boot long enough to be able to change it back.
-DD-WRT. Installing DD-WRT (or any other firmware replacement) is NOT for beginners or the impatient. You MUST read through all the info on the DD-WRT site and know exactly how to upgrade your exact model router properly and with the correct firmware version. Failure to do so may brick the router.

Anyway, if you keep it simple, and treat these units right, add a good antenna and UPS, they can do awesome things. In fact I wish they still made them. The new UFO type Linksys routers pretty much suck and are much less capable when running DD-WRT as they have small FLASH memories and can only run the mini DD-WRT version. On top of all that, no external antenna or antenna port.

Thanks for the instructable and good luck with your WRT's.

NostalgicStone (author)  Tachyon5 years ago
Some great info there!
I am sure that many users will benefit from your comment here!
This is not for the common everyday user by any means!
Like I wrote about in the Instructable:
“Most versions of this router have the ability to upgrade its firmware to an open-source Linux build called DD-WRT downloadable from DD-WRT (free). If you decide to upgrade to a firmware on this site, PLEASE read ALL the directions, FAQ, Wiki and Forum EXTREMELY THUROUGHLY, as improper firmware flashing can leave you with a very expensive paperweight. I cannot stress this enough! You have been warned!”
We could spend days and days debating on whether or not the fans/heatsink/overclocking etc is necessary, but there are tons of forums online devoted to that specific issue!
This is Instructables, and I encourage everyone to improve on each others concepts, EVEN IF IT IS OVERKILL LOL!
As posted in the original instructable, I ask that you do not fill this section with "you don’t need heatsinks" type of comments.
This is for the people who have obviously demonstrated overheating issues, and would like to install fan/s on their unit!
If people want to add them, they will.
If they don't, then they won’t!
It is always a good idea for users to do lots of research for themselves, and trial and error is one of my favorite types of said research.
As I have stated before, I have burned out 2 of these units without using the heatsinks, and stability issues with others. (especially with heavy torrenting)
Were talking at least one reboot needed every day to regain stability.
After adding an internal heatsink/ fan, I, as well as many others have seen a huge increase in the stability of the router.
If you believe that it doesn't need them, or you think that every single other user who has reported overheating issues (especially with heavy torrenting) is just making up stories then don't do it!! No one is telling you that you have to!
I am not the only one who has had issues with this unit overheating, so I am not alone when I say that it DOES make a big difference.

Wardrivers are my largest advocates of these modifications, as it was a group of them who brought up the issue to me in the first place. They rarely have a "reasonably well ventilated area” and most of them in fact DO use them out in the open sun!

Also, when turning the TX down, I lose about 5 connections from neighbors, maybe its just a huge coincidence every time I do it.
But, again, this is not an Instructable about DDWRT!
I have a great idea! You should make an Instructable about all the settings in DDWRT, their benefits and possible downfalls! I would love to learn more about the subject, and I’m sure that almost every user who is interested in this page would be more than excited to learn about all the cool features that DDWRT provides and the possible side effects of each of them from a knowledgeable Instructables community member!
Let me know when you have it up and I will be more than happy to post the link in this Instructable!

If your studies have brought you to understand that it makes no difference whatsoever, then do it how you think it should be done!
This Instructable is in response to an overwhelming amount of users who tell me about overheating issues, and I simple cannot afford the time to mod them all myself :/
I am not advocating that every user needs to do this, as the majority of home users will never benefit from such mods at all!
I agree about the newer models, they are way nerfed in comparison.
Bring back the ram!!
Thank you for the educational and experienced input!
Overheating is a symptom. It is not a root problem. It has one of three causes, which I already mentioned.
- Overclocking. It causes heat, and instability. You heatsink fan DOES help with this cause. But I haven't seen a real use for overclocking one of these routers. RAM becomes a limitation before CPU power does.
- Overpowering. Upping the TXPower causes the RF section to overheat, causing failures and crashes.
- Bad power. For example, in your wardriving scenario. How is the unit being powered? Likely it's an Inverter plugged into the vehicle and the wall wart plugged into that. Very few of these have pure sinewave output and the combination with the wall wart causes problems.
Or it's a direct rigup to the 12v of the vehicle which people assume is OK since the WRT's run at 12v as well. However, in reality, vehicle DC tends to run from 12.5v to over 15v. The WRT's onboard regulator has to do something with the extra volts. So it dumps them as heat. The unit is not designed for that. And that doesn't include the noise in the power coming from a vehicle.

As for the TXPower issue, there are two types of users. wardriver type users and regular or normal users. Wardrivers are interested in different results than normal users. Wardrivers want the most connections over the most distance. Normal users want the best speed with the least errors. These are opposite goals.

Upping the TXpower WILL get you more connections and at longer distances, but it's a trade off. The unit will see more packet errors. To compensate it will step down the connection speed. For 'normal' users this trade off is not worth it given their goal is not to reach every AP in the neighbourhood. They just want fast, clean network connections throughout their house. For them, an external antenna upgrade will always give better results than uppping TXpower IF error rate and link speed are a priority.

All that said, my comments were not meant to disparage your instructable, but to add info that 'normal' users might find useful to help them decide what route to take with their WRT based on their usage. Wardrivers will likely be all over this instructable as it's great for that type of use.
NostalgicStone (author)  Tachyon5 years ago
Most everyday household users will not need to use any external mods of any kind.
This mod is not for everyday household users.
Thanks again for the input buddy!
Anyway, you got me thinking. I'm tempted to do some of this to one of my personal WRT's. I'm thinking about just adding a heatsink to the 'CPU' and possibly some of the other chips. Then see if I can get a small enough fan to pull air into the unit and still mount inside the case.
I also want to put together a cheap DC-DC converter that does good filtering so I can use the router with crappy power sources like automobile 12v.

Finally, you might be interested in RadioLabs. I've used antennas from them in my site to site links and have been very happy with them. I've been happy with those and the D-Link 7dBi omni.
For you, the mobile antenna (only one needed) is war drive gold.
Or for sucking in every AP in the neighbourhood, their 15dBi omni is pretty awesome.

I use the Flat Panel 13's for my point to point links. One of which is 85 meters and still connects at 54Mbps unless it's rainy or foggy in which case it steps down to 48.
NostalgicStone (author)  Tachyon5 years ago
 Thanks for the advice Tachyon!
I have used a couple much larger Cisco antenna in past builds, and I was amazed at the connections they could pick up.
I personally am not a Wardriver so I'll talk to the boys about the mobile antenna and chances are at least one of em are going to want to give it a shot. It surprises me how competitive they can be!! Sometimes I feel like a corrupt banker funding both sides of the war XD

One thing I know they would totally eat up is if I stared making them with a battery switch.
I'm thinking li-ion obviously, and it's gotta charge when plugged in. Some sort of charge meter is also a must! (even 4 or 5 tiny leds would do)
Theres plenty of room in the case for it, but I've never personally done it and would love to give it a shot.
Any suggestions?
If you or anyone else has suggestions in regards to this, please send me a sketch up of your ideas!
Thanks again buddy!
cypherpunk5 years ago
you make this look really easy, but i cannot remove the shell.  is there a trick to getting the blue part off?
NostalgicStone (author)  cypherpunk5 years ago
Press your thumbs against the font pegs on the underside, while pressing the rear of your hand against the rear pegs. It sometimes takes quite a bit of force, and usually will literally shoot off once its let go. I just added captions to the photo of the removal to help.  
camintmier5 years ago
I've got a WRT54GL 1.1fw and the latest stable version of DDWRT (v24 SP1) always dropped packets for some odd reason.  Might want to try the Tomato firmware.  I'm running the latest beta of it (v1.28.1812) and it works great.  Not exactly as customizable as DDWRT, but if you need fairly bulletproof firmware for everyday use, you might want to try it out.
NostalgicStone (author)  camintmier5 years ago
Thanks camintmier,
I have heard mostly great things about the Tomato firmware.
There are several different firmware versions available for this and many other routers out there.
Depending on your own personal needs, a little research could provide the best solution for you!
I have added an additional slide in the Instructable with a list of popular firmware releases.
Thanks again!
wlohsen5 years ago
The reason commercially available antennas don't exceed 6dBi is because it is illegal. You can transmit a max of 1 watt with a max antenna gain of 6dBi in this band by FCC rules. By increasing your antenna gain and not scaling back your output power, you are technically breaking the law. just an FYI
NostalgicStone (author)  wlohsen5 years ago
 Linksys must be breaking the law on a massive scale then :/
Read the FCC rules under step1 "Legal" in the Instructable.
Thanks for the input!
They say peak gain of 7dbi. They never list whether the frequency that achieves that gain falls inside of the wifi range. ;-).  Also, you assume the linksys routers are transmitting at 1 watt. You are allowed to use higher gain antennas but you have to scale your max power output to compensate.

I posted the link to the FCC rule above. you can decide for yourself if they violate the rule or not.
NostalgicStone (author)  wlohsen5 years ago
You are welcome to view the FCC FAQ as posted in step 1
Thanks for the input!
psic5 years ago
 Hi, I'm just wondering how much you overclocked this router in the DD-WRT software?
Lance Mt.5 years ago
I'm under the impression that i could use this to run a server in my neighbour without the use of a isp? Useful.
Good info

However, the 9dbi antennas may create more drop outs and dead spots than the factory antennas.

Remember, when it comes to omni directional antennas, more gain does not mean better performance.

In order to achieve 9dbi, the beamwidth of the pattern has been squashed flat thus all signals that are coming from high angles will be much worse than lower gain antennas.
NostalgicStone (author)  WIFIENGINEER5 years ago
Ooops! Did not mean too delete my response
(Thank goodness for Lazarus)

Thanks for the info!
If I put the stock antenna back on, fewer neighbors are able to connect to the network. With the 7dbi attached a couple of them (5 or 6 houses down) report being able to connect sometimes, but not others. I assume this is because of the problem you are speaking of? I would love to learn more about this!
iamthejae5 years ago
 i like the work you have done, great job!
i have one of these routers as well but only have a customizable version of tomato linux running. i would love to have expandable options, but dont think i would be upto doing this myself.

how much are you thinking of selilng the modded routers for? and what if i were to give you my WR54Gts in exchange?
ynns15 years ago
OK I see now. It was the 'spiral' thing that threw me. Twisting multistrand wire to avoid fraying before soldering is second nature to me, so I assumed that something more than that was required :-)
Thanks for the clarification and the great tutorial.
NostalgicStone (author)  ynns15 years ago
 Thanks man!
I added the extra umph to that step because in all honesty, I forgot to do it in the picture! XD
Thanks for the imput!
meh3015 years ago
warranty well voided :p
NostalgicStone (author)  meh3015 years ago
 Thanks :P
OK well first let me say that the instructable is great!!!! and that i will be attempting this mod soon!!!!!! but one (might turn in to a few) questions? first one for now is ... if not eBay for the dual 9db antenna then where might one acquire one of these?

and would these same steps work for a wireless b router of linksys? and what effect would it be for a B router?
thanks again

NostalgicStone (author)  davidglinski5 years ago
 Yep, same process. Cisco makes some amazing antennas, but they can be kinda pricey. Their 7dB omnidirectional antenna seem to work better than some off-brand 9dB antenna that I've tried
thanks ... but one last question ... i tried finding my linksys wireless B broadband router in the link above to see if its compatible but i cant find mine on there does that mean i cant do this? btw my model number is BEFW11S4

NostalgicStone (author)  davidglinski5 years ago
Oh no!
If the router is not listed, then unfortunately it is not compatible with the DD-WRT firmware.
Try typing in your router model on this page DDWRT CHECK
showup5 years ago
Very useful instructable. What is your opinion on this antenna? Also can you post a link to the antenna that you are using? That will certainly benefit many of us.   Thanks in advance.
NostalgicStone (author)  showup5 years ago
That antenna wont fit on the WRT54G series unfortunately.
Look for a TNC connector type :)
For everyone looking for good antenna!!
The antenna in the above post were supplied to me by the end user who bought the unit. 
In my personal at-home model I use 7dB Linksys antenna HGA7T that I found in a box of computer crap at a mom and pops store for $25, and they work great! I don't have a link for you, sorry, but Google HGA7T and you should find what you are looking for!
Drewbaccaa5 years ago
With this modification combined with the firmware would it be able to capture a signal from a nearby scource and rebroadcast it in to your house... thereby capturing unprotected wifi?  
 That's exactly what I do... I can only pick up the signal in one part of my house so I put my DD-WRT router (Linksys WRT610N) there and have it configured as both an access point and a client.  I had it set up at first as just a repeater but decided I prefer it this way so that I can have secure access to the wired devices hooked into the router (Wii, NAS, etc).
MRedmon MRedmon5 years ago
 Oh, and I don't notice a degradation in speeds vs connecting directly to the host wifi signal (but I haven't run actual tests).
NostalgicStone (author)  MRedmon5 years ago
You know, I have only tried it on one network before with this set up, and I got poor speeds. It is possible that I didn't set it up correctly! Someday I'll have to do some actual tests lol!
NostalgicStone (author)  Drewbaccaa5 years ago
Yep. You can use it as a repeater. It will be much slower than the host connection speed tho. If you try it out, let me know what kind of results you have!
kronflux5 years ago
didnt take the time to read all the comments, so I'm sorry if this is a repeated comment. but it seems to me that the external fan would interfere with proper airflow with the internal one. the combination of the two would wear out the internal fan a lot quicker, and the reality is, the external fan wouldn't even really provide any benefit whatsoever. the only thing I could see being useful is to add some form of a tiny tube above the internal fan, so that it grabs its air directly from outside of the case(several PC cases have this on the side panel for the CPU fan to grab air externally)
I think this is what I'll end up doing. the external fan is definitely overkill, and will make the router sound like a jet engine.
NostalgicStone (author)  kronflux5 years ago
Yep, it sure is loud! You are right about that!
This is not a mod to add to the router you use right next to your desk.
Try your way for yourself!
This Instructable is not a "the-only-way-it-can-be-done" kind of Instructable.
If you only need the interior fan, have at it!
I just know that the ones I have worked with, when overclocking to its max, still tend to overheat after a day or so of heavy torrenting with just the interior fan installed.
When JUST using the exterior fan, I get the same results.
Each scenario is a case-by-case and everyone’s needs are unique, so do some experimentation for yourself and find out what your specific needs are, then do it!
This build was actually requested by multiple people, so I started making them and never looked back J
I've had 2 routers running with these mods for over a year now.
Router 1 is a WRT54G with JUST the internal fan, and stock antenna for the home network.
Router 2 is a WRT54GL with BOTH Fans and a 7dB antenna for the neighborhood WiFi.
Neither one is showing any signs of wearing out whatsoever!
As described in the main post “This type of upgrade is most useful in very large households, businesses, neighborhood-Wi-Fi, trailer parks, RV parks, campsites, etc.”
For home use, yea it’s definitely overkill!
Thank you for your interest!
azega5 years ago
So, if you didn't use the ebay antennas, what antennas DID you use? Do you know if they actually perform better than the stock antennas?

With the addition of fans and boosting the transmit power, you're putting a lot of load on the built in power supply. Have you thought about bypassing it with a better supply? This might also fix the issues you were having with stability.
ynns15 years ago

Given the fact that you added an active cooler to the CPU in the previous step, isn't the addition of this fan an overkill?
I'm asking because I'd hate to cut up the case of my router (I'm really attached to the thing!)

NostalgicStone (author)  ynns15 years ago
 I hear ya man.
Do some experiments with JUST the internal heatsink/ fan and find out what setup works best for you!
If you don't feel that You need an external fan, then don't install one.
I recommend trial and error personally, so give it a shot and let me know what your results are :)

Jason918875 years ago
 Great job! I am using a Buffalo Router that is DD-WRT flashed and I was wondering how it was done. I love the options I have. 
SinAmos5 years ago
The problem with dd-wrt and onion is there lack of IP refreshing.  They just don't refresh, so i can't chang my IP to save my life on these suckers.  Plus, their repeater mode sucks, which doesn't let you expand your network to wired boxes via wireless.  I hacked a t-mobile freebie with a jtag cable years ago, but I don't use it.  I think I put tomato on it, which was cleaner than dd-wrt.  I might revisit the router and check out the upgrades on the soft.  I think I have two of these just sitting.:)
ynns15 years ago
Can you please explain the need to twist the ends of the wire to create a spiral? So far it seems a 'straitforward' soldering of a wire to two pre-existing solder points so what's the need for it?
Personally, ive found that twisting the wire prevents it from "fraying" or spreading apart during soldering, when solder is applied, and heated, the wire seems to spread apart easy, ive always done it to, it just seems to keep it cleaner.
NostalgicStone (author)  tysonscott20025 years ago
Yes thats true!
When you press a non-twisted wire down on a through-hole solder point, once the solder melts, the wire does tend to "fray" as you put it, and has a nasty tenancy to slide around.
Thanks for pointing that out tysonscott2002! 
NostalgicStone (author)  ynns15 years ago
Great question!
It's a trick I learned when training for either my J-STD-001 or the
IPC-A-610, can't remember. Basically it ensures a stronger connection between the two, especially over long periods of time in units that have much vibration.
Im sure that NOT twisting the wire would work just fine, but I've been in the habit so its not really any trouble to do so.
arhodes185 years ago
 Did you make or buy the antenna? If you made it, have you thought about an instructable on it?
great 'ible btw!
NostalgicStone (author)  arhodes185 years ago
 I did not make the antenna.
I have made some in the past, but they don't even nearly match up to the professionally made ones. lol
MotaBoi5 years ago
 How far can this amplify the range to?
NostalgicStone (author)  MotaBoi5 years ago
Good question!
Read below, a couple other people had the same question :)
Thanks for the interest!

tieguy5 years ago
I've gotta say, I've been visiting this site for about 3 years now and have seen a lot of great instructables; but this has to be one of the best. It's well detailed, done neatly, and actually serves a purpose.

  I recently upgraded to DD-WRT so I could use it as a wireless adapter for my xbox and a server I'll be putting together in the future, I'm loving all the options on it and I'm totally gonna do this mod once I have the cash(I'm broke). What kind of range does it have?

Seriously outstanding job.
NostalgicStone (author)  tieguy5 years ago
Thanks buddy!
It's range greatly varies depending on your environment.
I haven't tested it in an object free field or anything, but walking away from the house with a laptop WITHOUT the overclocking, signal boost, and 9dB antenna, I only get a signal for about 50-60 yards. WITH all the mods i get about 90-110. There are also lots of trees, cars and mailboxes so it's difficult to guage but there is a definite increase!
junits155 years ago
thats a nice login screen you have, for vista or seven? and where did you find it?
NostalgicStone (author)  junits155 years ago
For 7. Not sure where I found it, been collecting sweet hi-def pictures for a couple years now. If you want any just pm me with email :)
Theres plenty of login changing tools out there, this one works on all versions of windows and its free: LogonStudio

10pound5 years ago
Wow dude, for that being your first instruct able, you grand slammed it!  Funny, informative, detailed and best practices all around.  Well done.  Ive been modding these WR54Gts for sometime now and I couldn't take issue with anything you did.  Ive been experimenting with using only the innards of them and making my own cases from lexan and such.  Now I am thinking of making my own instructable along the same lines. Cheers.
NostalgicStone (author)  10pound5 years ago
Hey Thanks!
I have been thinking the same thing!
Definitely let me know if you come up with some sweet new cases :)
BrianKT5 years ago
Nice first Instructable! Very detailed and planned Instructable. It's good that you upgraded your router hardware to support the upgraded firmware.
wsanriv5 years ago
I really like this modification because if you have a software mod on your linksys box and you raise the signal power, heat becomes a problem, but with 2 fans working inside and outside heat is a problem no more.

Gratz really cool project and tons of illustrative images.
NostalgicStone (author)  wsanriv5 years ago
 Much appreciated!
ERCBIENG5 years ago
 How much more does the signal area reach with this type of modification?
NostalgicStone (author)  ERCBIENG5 years ago
 The antenna are the only part of this mod which will increase the coverage area. I have not tested the router in an object free environment, but walking away from the house with a laptop WITHOUT the overclocking, signal boost, and 9dB antenna, I only get a signal for about 50-60 yards. WITH all the mods i get about 90-110. There are also lots of trees, cars and mailboxes so it's difficult to guage but there is a definite increase!
Phoenixmill5 years ago
so it boosts the signal of the router?  thats what its used for?
NostalgicStone (author)  Phoenixmill5 years ago
 The DD-WRT firmware replacement has TONS of features that are not available with the factory firmware. One of them is an overclocking feature which unfortunately can also increase the temperature to unstable levels in many units. This mod is a solution to overheating issues for those who want to push the envelope!
pcapelo5 years ago
good job. I liked the level of details.