Introduction: Increase and Extend the Range of a USB Bluetooth Dongle!

Picture of Increase and Extend the Range of a USB Bluetooth Dongle!

This modification is something I came up with after struggling to get a reasonable range from my Nokia N82 to my computer in another room.
The victim was a $8 USB Bluetooth dongle, with a usable range of about 10 metres (less through walls).
Being a radio ham, I am familiar with antennas, and know how critical it is to get the CORRECT antenna length, if your signal is going to be efficient.
I was surprised to find other 'range extender' mods on the net, which did not mention this important fact! (One site had someone who had attached a "foot long piece of wire" onto his USB dongle and was wondering why it didn't work very well!!!)
There is a recognised formula for calculating antenna length/frequency, which is (without going into detail) 300/frequency - i.e. 300/150(MHz) will give you 2 metres.
As Bluetooth devices work at frequencies of around 2450MHz, the formula will give you an antenna length of +/- 12cm.
This figure then has to be divided by 4 to give us a quarter wave antenna, which will be 30mm in length - THIS LENGTH IS CRITICAL!!!
25mm or 35mm will just make it less efficient (Lower range).
Your old CB antenna WILL NOT WORK!
So - if you are happy to try something (at your own risk), and want to get a significant increase in usable range for you dongle, go to the next step, but remember, the end result doesn't look pretty, but performs brilliantly!

Step 1: Opening Up the USB Bluetooth Device

Picture of Opening Up the USB Bluetooth Device

To get started, we obviously have to get inside the dongle.
The picture shows the dongle with the 'antenna' on the side removed.
Don't worry, this antenna is just a plastic dummy, and performs no function at all!
The plastic case then has to be prised open, using either a flat blade screwdriver, or a blunt knife.
There are no screws.

Step 2: Inside the Bluetooth Dongle

Picture of Inside the Bluetooth Dongle

OK, so now we're inside, and you should be looking at a small PCB (printed circuit board).
Having second thoughts now?
If you aren't confident with a soldering iron, simply pop everything back together again, and forget this mod.
If you are ok to continue (a small glass of whiskey will help!), then we'll move to the next stage.
On the side of the PCB with the 2 chips and a 13MHz crystal, you will see a hook-shaped silver line at the top of the board (I've marked this in YELLOW on the picture).
This is the antenna which you're using at the moment.
Now you can see why the range is somewhat limited!!
Ok, bite the bullet, because this has got to come out, and you're gonna remove it.
It is easier than you think, all you have to do is find a sharp utility/hobby knife, and simply SCRAPE IT OFF THE PCB.
Be very careful to scrape towards the edges of the PCB to avoid damaging the other smd components on the board.

leave enough of the old antenna on the board to give you something to solder you new antenna onto.
I've marked the STOP area in RED on the pic.
DO NOT remove all of the old antenna (leave about 3-5mm)

Step 3: No Going Back Now!!

Picture of No Going Back Now!!

Right - The old antenna is now removed. The Yellow shows where it was, and now you should have a small left-over piece of the old antenna to give you something to attach (solder) your new antenna onto.
For the new antenna, I used a 30mm (CRITICAL!!!) piece of rigid copper wire (earth wire etc), which gives a better bandwidth, but is also liable to pull the old antenna track away from the PCB if soldered directly onto the track.
For this reason, I made a small hole in the PCB, using a small watchmakers' screwdriver (you can use a dremmel or 1mm drill bit).
Whatever method you use, make sure you support the PCB on a firm surface, to avoid stressing the board while you're making the hole.
The antenna is then threaded through the PCB from the other side.
Now it gets tricky, because you cannot hold the wire while you're soldering it to the track (it's too hot), so you need to find a way to support the board while you're soldering it.
Also remember to 'tin' the wire, before you solder it (it gives a better connection, and also solders quicker so you don't overheat the other components).

Step 4: New Antenna Is Now Attached.

Picture of New Antenna Is Now Attached.

When soldered in place, the antenna will now stand up vertically from the PCB, and is likely to come unattached, or break the old track (antenna), if you try to play with it (bend it straight etc), so LEAVE IT ALONE!
At this point, it would be wise to check that you have soldered it correctly, and have a good joint (connection).
HOLDING THE PCB BY THE EDGES, plug it into your USB socket (I use a short extension lead), and see if the LED lights up, and the device is recognised.
Don't touch the components while you're plugging it in, because you are almost certain to short something out, and totally wreck your new improved dongle.
You should already have a good idea what range you had before, and should now be able to see a significant increase in the operating range.
If you live in a well populated area, do a device scan to see if any phones etc are in range (you'll be surprised).
If all is ok, then you have another problem - how do I get it back into the plastic case?
I just used my still hot soldering iron to make a hole in the case for the antenna to poke through (I never said it was going to be pretty!!)
The hole should be in the plastic case which does NOT have writing on it, and is located level with the little plastic 'ledge' inside, where the PCB sits - on the opposite side to the hole for the 'dummy' antenna.
If you don't get the hole position quite right, DO NOT try to bend the antenna to fit through, make the hole bigger - you will avoid ripping the track up on the board.
As you can see from my picture, I got the position wrong, so just made a bigger hole. (ugly, but practical)

Step 5: That's All Folks.

Picture of That's All Folks.

With the case back in place, you're now the proud owner of probably the worlds ugliest looking USB Bluetooth dongle!
BUT on the positive side, you now have a Bluetooth dongle which will outperform anything for less than $50!
The range of mine is now a lot more than the 10-15 metres I got previously, with every room in the house being in range, and a 'line of sight' range in excess of 200 metres!
You could, of course, add a parabolic reflector (aluminium wok etc) to get ranges of more than 1 or 2km, but for practicality, I find the range more than adequate for my needs.
The same mod can also be applied to WiFi dongles, with similar increase in usable range, but I don't want to experiment with my $35 WiFi adaptor just at the moment (I'm poor!)
Also remember that Bluetooth operates a 'handshake' protocol, where it needs to recieve a signal, as well as transmit it, so if your phone has a naff bluetooth system, then don't expect to get much increase in range.
For sniffing out other devices in the neighbourhood though, you should find signals you couldn't detect before.
There are other antenna designs which you could also try (co-linear etc) which will improve things even more, but this design is a quick and cheap (free?) method to get the most from a cheap Bluetooth device.
Apologies for the terrible soldering in the picture, but I used a soldering gun for the job (yikes).
Any comments or questions can be sent to me at:
Good luck, and thanks for viewing.


billb (author)2009-04-09

Please excuse my ignorance!!!!! If your antenna radiates 360° how is by turning it on its side will change its radiating properties. If vertical is 360° horizontal should also be 360° I'm clearly missing something. This is a SUPER COOL hack which I'd like to try but I'm missing something on the radiating pattern thing.

Nottslad89 (author)billb2011-03-21

I always say, 'only a question unasked, is dumb', so no worries.

Sorry for the late reply (2 years!), and no doubt you already know the answer.
Anyway, the 360 degree radiated pattern is formed around an antenna in a 'doughnut' configuration, and not like a sphere or ball surrounding the antenna.

Most of the signal is generated within this 'doughnut', with very little at the end of the antenna (the signal doesn't go up or down, only around).

If the antenna is horizontally polarized (laid down), the least amount of signal will be wherever you 'point' the antenna.

The signal degradation between a vertical and horizontal antenna is also a key factor, so if the TX antenna is vertical, then the RX antenna should also be vertical, or visa-versa...

Hope that cleared it up.



et1nusn (author)billb2009-06-15

if one antenna is vert and the other is horz. you lose 3db (which is 1/2 the power) in which is called polerization mismatch. hopefully this is the answer you were looking for.

BenjaminJ2 (author)2017-11-10

I recently bought a usb bluetooth dongle from ebay for $2 with free shipping for my dad, it only worked at a maximum of 10 feet, so I popped open the plastic cover and cut a three inch strip of tin foil and folded a tiny area at the end of the foil strip and wedged it under the printed circuit antenna and put the cover back together and now I can get the bluetooth speaker to work 200 feet direct line of sight, it even worked in my dads walk in closet on the other side of the house.

ToddW71 (author)2017-11-10

Is there an optimal gauge size for the solid core copper wire antenna? Since the length of the wire is important and your calculations are precise to the mm, it would seem as though the wire gauge might also have an impact on performance. Thanks for the great post!

ArgleB (author)2017-06-11

Well whaddya works! Amazing
what a little theory does. I just tried it on a cheapy $2 ebay dongle
that wouldn't get more than 1 metre range before the signal started to
break up and crackle. Now I've got about 5 metres! I did accidentally
pull up the remainder of the trace but my solder joint held. A little
dab of hot glue should hold it firm.

Also, don't bother picking
out all the existing antenna, simply make a wide cut in front of where
you will solder and the antenna is not connected anymore.

The original was ~45mm long

Thanks Josh

fcampbell (author)2009-11-25

I appreciate the formula for calculating antenna length but I have a few questions.  You place a lot of emphasis on the correct length of the antenna but what about the conductor and wiring leading to the antenna?  If you solder a 30mm length of wire to a 4mm remnant of the old antenna, doesn't that leave you with a 34mm antenna?  And then, what if you folded the wire into a fractal shape.  Should a fractal antenna be made from the 30mm wire or should the final antenna be 30mm across?

JoeF4 (author)fcampbell2017-03-30

The conductor between the antenna and the transmitter/receiver only matters in that it should be properly sized for the length required(antenna to transmitter/receiver) at the frequency which will be used.

In the sixty seconds I spent looking up "fractal antenna", I didn't find any made from wire.

FernandoMelo made it! (author)2014-12-20

Nice Instructable! I've made this, but I made a bit different... Instead of USB Dongle, I've used a JY-MCU Bluetooth module, like those ones we can find at Also, I did not choose a quarter wave antenna, I've picked up the full length of 12cm (300 / 2450 ~ 12cm), hard wire (telephone wire, like network cable wire). To finish, I have left my original antenna in place (just cut off about 1mm with a sharp blade to disconnect from the rest of zig-zag printed antenna), so if it don't work, all you have to do is solder the old antenna again.

The results is very impressive. Before this mod, my module was able to give about 8m of range, now is giving me clearly 30m.

NeemeN (author)FernandoMelo2016-11-14

I have similar zig-zag antenna built in, about 40mm lenght in total. How do you calculate additional antenna for that? Interesting, how come this doesn`t work in the first place? Range is miserable 3-4 meters.

Dashing Rainbow Dash (author)2016-05-11

Could I do this to my bluetooth headphones?

you can yes, just make sure the end result of the antenna is about 30mm in length, for the best results.

if the antenna on the board is about 15,, long, add a single wire that is about 15 mm long, and it should work just fine.

MarcusR31 (author)2016-05-18

I have bought 6 bluetooth audio receivers and I would like to increase their range, although when I open them, they seem to have printed their antennas inbetween layers of the PCB. Is there a way to increase it anyhow? Best regards

Peter2011 (author)MarcusR312016-08-03

i have ones with a similar design, where i bought a small handful to try out different methods..

the one that works best so far, is to use old ribbon cable, make the length about 15mm and add it to the end of the antenna on the board(the red part, yoinked your image, hope you don't mind)

i got a good 10 meter range boost from it..

BradE5 made it! (author)2015-11-13

OK I did it. Works WELL actually...Un-bul-LEEV-ubool!

From about 6 feet to easily over 50 feet. Coyote fugly, but who cares!

wrecche (author)2015-10-13

Nice work ! I am too jittery to solder efficiently, but the upside is the bluetooth dongle I have is a $2 gadget from china lol, so what is there to lose. :)

Actually, for the price and size (it's as big as a large dudes thumb nail) it's actually quite powerful already, it just doesn't play well with any interference.

Hoping something like this can resolve it, and if done properly, well it can't hurt aye !

hieunguyengmx (author)2015-04-09

Mrinny (author)2009-11-12

I don't understand how this works.
With this bluetooth hack the usb dongle range has increased from say the default 10mts to either 20mts or above but other devices like mobile phones etc. will still have 10 mts range.
So how would the 2 devices communicate if the mobile phone is say 15mts away from the dongle?
That is only the pc dongle would be able to reach the mobile phone but not the other way around, isn't it?
Am I going wrong here?

Nottslad89 (author)Mrinny2011-03-21

The whole concept of this instructable is based on modifying the ANTENNA, leaving the actual power settings of the device unchanged.

Your phone/PDA etc does not need to be altered in any way, as the antenna on the dongle does all the work, enhancing both the transmitted and RECEIVED signals.

Bluetooth relies on a 2-way communication between devices, and is configured to work when a 'handshake' with a device has been established.

Since I wrote this article, there have been many advances in bluetooth technology and the modification of the new devices is easy, with a simple firmware hack/update changing power levels of the TX.
That still leaves you with the problem of receiving a low power device, and an antenna is the only solution, short of modding the device itself.

In any case, bluetooth was and still is only a SHORT RANGE communication medium, but I enjoy pushing the limits!


THX 1138 (author)Nottslad892015-01-19

Easy with simple firmware attacks? How do I go about that?

I've got a Kinivo BTD-400 and it's super compact and puts the pitiful antenna in the middle of a three-layer PCB! It's impossible to find a Bluetooth 3.0 or later dongle that doesn't use this compact format. The future is truly dystopian!

madtaurus.z (author)2014-10-09

1. Is it posible to do it in a bluetooth headphones using a copper wire from a network cable?

arkid77 (author)2014-07-10

Another tip is to extend the distance of the bluetooth usb device to where you need it on the end of a usb extension cable, assuming your using a computer thats fairly fixed to one location. They can be a few meters long, even longer with usb hubs inbetween I believe.A site I found that helped me with issues of bluetooth reception (http// suggest I do this to improve my reception which worked.

sdobbie (author)2012-07-10

You can easily overcome the problem of the antenna ripping off. Encapsulate the solder joint in Araldite extra strong and it will not be moving anywhere. Also, it does not matter if you touch the components, I have handled the insides of spy pens and memory sticks and they have always worked afterwards.

LiquidLightning (author)sdobbie2013-03-19

Not very good advice... It is like saying, "It does not matter if you look down a gun barrel, I have done it before and I'm still here." ESD damage does not always happen, but it is real and will occasionally destroy sensitive components.

ematson5897 (author)2012-05-20

Couldn't you just cut the antenna trace with a hobby knife instead of scrape the whole thing off?

mcutee (author)2012-04-19

Its very informative post.I have tried it on my device.There is improvement.

suicidal.banana (author)2011-09-19

Nice tut, finally some actual insight!
Thanks, will prolly do this to my dongle(s) soon :D

rushatrout (author)2011-04-25

is it compulsary to remove the internal antenna????

admunt (author)2009-12-04

it very good to do that but i need to make more than 100M from antenna by bluetooth and the antenna  signal can run follow cable around my country (mean use cable substitute antenna, if u can do please email tell me i pay u my mail:

TripleHelix (author)2009-09-01

I Love the smell of modification in the morning !!!

Pazzerz (author)2008-11-24

Now that I see the case to give me a reference for the antenna mod position, it looks like you could have forgone the hole in the case and just soldered the antenna horizontally, leaving it entirely inside the case. Was there enough room for that, or did you have other diabolical reasons not to?? =)

Nottslad89 (author)Pazzerz2008-11-24

Hi Ken, Yeah, the vertical antenna gives omnidirectional (360 degrees) coverage, while a horizontal antenna, radiates from its sides, with almost no signal radiated from the ends. That's the reason for the vertical config. As I said in the article, the end result of my experiment is as ugly as sin, but it works well. If you spend more than the ten minutes I spent doing this, you can obviously get a neater looking result. Good luck :-)

Pazzerz (author)Nottslad892009-01-13

Here's an idea: The little hole in the side looks like a great place to put an antenna out that rotates to fold along the side of the case. ???

woody123 (author)Pazzerz2009-05-21

would it not be possible to use the rotating and folding link from the bottom of a radio antenna?

cornflaker (author)Nottslad892009-01-13

Hmm ok, I might make mine come out the side though as I had previously tried to solder my own antenna on and made a very neat hole in the side of my case (looks like it came with it :D) although that didn't work very well as i had no idea about size requirements etc so I had a rather thin approx 10-12cm bit of insulated copper wire half of which I coiled around a pencil then left the rest straight. It looked pretty good, but didn't work so well... I ended up just ripping it off because it didn't virtually nothing and it was annoying trying to not bend it

cornflaker (author)Pazzerz2009-01-13

Yea, good idea. Just use a bit of electrical tape to stop it from shorting stuff... But those diabolical reasons sound kinda fun ;)

themonkeyz (author)2009-02-14

Great Instructable! I did this for my Bluetooth dongle and where I was getting almost no signal it now stays at "Good" level. I didn't test it extensively but it seems to have at least doubled it range. I applied the same technique to a Wifi dongle. The circuit was a little different but it worked the same way. I had trouble soldering it and it became quite hot but nothing broke. I now see a lot more networks. I even see the AP of my WISP, wich is 2.5km away, from my basement! Ok, it's at -88db, and it probably wouldn't hear me but I didn't see it before. Next step would be to get my hands on that useless dish hanging on my apartment building's wall.

spiritiak (author)2008-12-07

is it save for pc? !If i do mistake can it damage my pc?

cornflaker (author)spiritiak2009-01-13

Don't worry you would have to mess up really bad for anything bad to happen to your comp, I've even run a little motor out of an old camera straight off my usb (without even using a connector! XD) it sucked so much power that all my other usb devices simultaneously disconnected, and reconnected when I quickly stopped lol no permanent damage was caused though so yeah if that didn't wreck anything I don't know what will.

decades (author)cornflaker2009-01-17

this is a quarter wave antenna (one fourth of the wave at 2.4gigahertx is 30 mm. The speed of light divided by the frequency in megahertz if you like knowledge..

cornflaker (author)decades2009-01-18

Um... what does that have to do with my comment??? lol

adamsdead (author)2009-01-15

ROFL I'll bet that smelled for a while afterward (I've melted plastics with my soldering iron before NOT a good smell hehe)

cornflaker (author)2009-01-13

Um, can I use some coat hanger for the antenna? I currently don't have any other kind of thick solid core wire...

cornflaker (author)cornflaker2009-01-14

Ok, I have some kinda thick solid core copper wire now (not quite as thick as yours but I'm sure it will do) But if I solder it on like in this picture, will it still work well? The dongle will be sideways when in use so the aerial will be pointing up vertically.

cornflaker (author)cornflaker2009-01-14

Damnit the jpg compression has made it so you can read the small writing, it just says that the yellow and red is the existing aerial and I'm going to remove the red.

etlerd (author)2008-12-27

Why is 30 mm a critical measurement for the antenna?

etlerd (author)etlerd2008-12-27

And how long was the original antenna track?

etlerd (author)etlerd2008-12-27

I wish I could delete this comment, as I just read the explaination :( But instructables is throwing errors.

fez_uk (author)2008-12-23

I like the idea of this and nearly bought the same dongle for the external antenna but thought it might unscrew like a wifi dongle. To my disbelief looking on the net it's actually a dummy antenna... Makes you wonder if this make of dongle is also really class1? Anyway as I said I like the idea but who wants a copper spike sticking out of their dongle. If knocked the track will come off the pcb and might stab yourself. I still will buy one of these due to the space thats inside the casing for adding extras. I'll probably make my own instructables showing what I plan. Cya around. Im also a Ham op.

spiritiak (author)2008-12-07

Hmm it's really work........i am noob but i did it successfuly.......realy good tutotial....realy thx.

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