Introduction: Emergency Signal-Boosting Cellphone Antenna

This simple, cheap and easy to make antenna can boost your cellular phone's signal enough that you stand a better chance of getting help in a bad signal area. All you need to make it is:

Some thin, solid-core copper wire (easily found inside phone wire)
Wire cutters
Tape measure or ruler
Drywall screw
Solder and soldering iron

Comments

author
Takelababy (author)2013-02-05

I just tried this with a 4 year old clam phone by joining 3 twist tie wires together and duct taping it to the upper half of the back of my phone. Went from no bars to one bar. The better indicator went from two bars to three. Reception in my yard is spotty and I'd wondered if this would work in an emergency. Will this screw up the phone?

author
Guy61 (author)2010-07-14

Hi I joined up to share some insite about ant.s as a ham radio operator it's manditory to learn about the way ant.s can harm your equipment the mesurment is the SWR signal "all antennas must be matched to the frequncy they transmit on" !!! It will also inprove reception so you cut the antenna useing a formula for the perfict SWR ratio if you don't the power radiation comes back down the wire and frys your front end. Most ham operators learn how to trim there antennas for this problem as it's very costly not to. As it's a simuar tech these rules must apply in this case. Also you must take resistance into the factor as even a T.V. Only works with a matching resistance. Hope this helps some of you.

author
luvit (author)2010-05-17

 it was like having a 7 foot antenna connected to my phone.

author
fourxguy (author)2007-12-11

Hey Hoopajoo thanks for the tip... went from 1 bar to three bars and can now make calls from my downstairs bathroom. Could not do that before making this antenna. Only have one problem... when I take out the antenna I can't get any bars and my phone says " Searching for Service". Even in an area where I used to get three bars it still says " Searching for Service". It seems that the phone is dependent on that cool little antenna now. With out the antenna my phone is just about useless? Any ideas how I can get it back to my original state before using the antenna mod? I am using a LGVX8600 on Verizons network in So Calif.

author
seventenths (author)fourxguy2007-12-11

I tried this project last night... After a quick stop into the local verizon shop, I wanted to jump online and post a warning. Well, Fourxguy beat me to it with the exact same problem except my phone is an LGVX8100. With two months to go before my "free" upgrade, I'm now sitting down to try and wind the wire antenna inside the battery compartment as a temporary affair. JF

author
Briguy9 (author)seventenths2009-07-16

um, just use wire cutters and snip most of it off.

author
Hoopajoo (author)fourxguy2007-12-11

According to my neighbor who is a tech for Alltel (named Chad, NO CRAP), the cmos for many LG phones has this buggy 'feature' that remembers the use of an external antenna and will default to it until the cmaos is reset. This is done py powering off the phone, removing the battery, holding the power button for 10 seconds with the battery out, replacing the battery and then powering on. He said that this should fix it. Sorry for any trouble. I tested this on my wife's LG and nothing happened, but hers is a LG Wave.

author
fourxguy (author)Hoopajoo2007-12-13

I tried this and it did not work :{ Thanks for your reply!

author
seventenths (author)fourxguy2007-12-13

Ditto...

author
konablue (author)2008-05-29

WARNING: Do not try this with ANY Treo smartphone unless you want to screw it up. There have been two identical instances already. As a precaution I would not try this with any phone unless you have found an example where someone else has already done it.

author
burning_feather (author)konablue2008-08-07

how about a moterola razr?

author

so... does it work on the Motorola razr?

author
konablue (author)burning_feather2008-08-07

You can try at your own risk. Maybe if you use smaller gauge wire it'll work better. I won't be trying it ever again unless it's an old phone. But people have apparently done it easily sooo.... your call!!! Good luck

author
burning_feather (author)konablue2008-08-18

thanks

author
obamafan (author)konablue2008-05-29

I have a Treo 700 that I have used this on. It worked well and didn't even mess up my phone. I was stuck on the side of the road when my Nissan broke down and when I went to call for help, I had no bars at all. I had made this antenna in advance and kept it in my toolbox for just such an emergency. With it I went from zero bars to 3 bars and was able to get a tow. I followed the instructions to the letter and found the telephone wire to fit perfectly without the solder. What gauge wire did you use? Also, how deep did you stick the wire in? Common sense says not to shove it in hard and deep. Besides, the title says EMERGENCY signal boosting cellphone antenna. What was your emergency?

author
konablue (author)obamafan2008-05-29

14 gauge copper. I am getting one bar now so my phone isn't completely useless. I get no bars inside and one or two outside. I was testing it so I'd know if it would work in an emergency. I did not shove it in very far. Glad to hear it worked for you. All I know is that my phone doesn't get the reception it used to and neither does the guy's in the other post. Hopefully it will come back somehow.

author
obamafan (author)konablue2008-05-30

14 GAUGE!!! That's WAAAAAAAYYYYY too big! No wonder you screwed up your phone. Phone wire is about 24 gauge and solid copper. What you did is like using automotive jumper cables to connect a watch battery to a circuit board. Yikes!

author
konablue (author)obamafan2008-05-30

So I halfway fried the internal antenna?

author
obamafan (author)konablue2008-05-30

Probably only has a partial connection on the board. The antenna on most models run through the external plug, so you probably partially damaged the external plug and the internal antenna doesn't have a good, solid circuit. If you are good at micro-solder, you could probably bypass the plug and fix it that way.

author
Exitao (author)2008-12-04

I believe it's actually a switch inside the antenna socket that disables the internal antenna. Problem is, the wire didn't have the right shape and the switch didn't reset. Same thing can happen if you use the wrong GPS antenna.

author
Iresuqay (author)2008-10-16

Yeah... the antenna works, but after I took it out of my VX8300 its like the normal antenna is disabled and it only wants to use the external one. Would a bought external antenna do the same thing?

author
davethegiant (author)2007-12-19

Yep I am pretty sure this screwed up my Treo 700p. I get no service with or without my little homemade antenna. Crap. Any help?

author
Hoopajoo (author)davethegiant2007-12-19

I'll speak with my friend who works for Alltel in the morning. I'll see if he has any other ideas and will let you know ASAP.

author
davethegiant (author)Hoopajoo2007-12-20

I am going to try a hard reset and see if that works.

author

Nope...

author

hehe, well 50 bucks on my deductible sucks, but hey I get a new phone, eh?

author

OH I did get the home made antenna to work though, so I am not without phone.

author

My Treo hasn't been the same since I tried to stick an antenna up it's butt, now I am working with a mid 1990's Nokia. ugh

author
konablue (author)davethegiant2008-05-27

how exactly did you screw it up? i have a 680 that i was gonna make one for just for kicks since i dont need it. did it break off or something?

author
davethegiant (author)konablue2008-05-29

I think it automatically disabled the internal antenna, or at least that's all I can assume. It wouldn't work without it after I made and installed it. I walked around with this wired monstrosity for a couple of weeks. Don't be the butt of a joke by trying this if you have a Treo.

author
konablue (author)davethegiant2008-05-29

Too late I frigged it up big time. I havent been able to get the external one to even work. I doubt I have insurance or warranty. I found one website that's selling the back housing including an antenna. I wonder if that would fix everything for 40 bucks. My guess was that I somehow shorted out the original antenna. But if it's just disabled there must be some way to turn it back on...

author
davethegiant (author)konablue2008-09-02

So, did that ever work for you or did you just junk your Treo?

author
creative zen (author)2008-05-15

jeez this guy should narrate for a living

author
Hoopajoo (author)creative zen2008-05-16

Thanks!

author
i make shooting things (author)2008-05-15

sweet. I always wondered what that little thing was for. You can just poke a hole in the rubber with the tip of antenna

author

On average this lowed my reception by 2-4 bars (i was looking froward to excellent results)

author

You might need to tweak the coil spacing to suit your particular part of the band

author

I verizon service is that significant?

author
lmaoguy (author)2008-03-05

whats phone wire? im dumb XD

author
xrobevansx (author)2007-12-08

didn't work. Bummer. I was hoping it would.

author
Hoopajoo (author)xrobevansx2007-12-08

Is your phone CDMA or GSM? There is a bit of a frequency difference between the two that can be conquered by playing with the coil spread. Also hold it close to your body as all antennas need a good ground-plane.

author
xrobevansx (author)Hoopajoo2007-12-08

Sprint...so......CDMA?

author
Hoopajoo (author)xrobevansx2007-12-09

Probably. Are you using the MCX plug? If so, then you might want to tin it for a more snug fit and better contact. That may overcome it.

author
Weissensteinburg (author)2007-12-06

Cool! I don't think my phone has a plug for it though =[

author

It can still work for you. When you make it, strip off 4cm instead of just 1cm from the bottom and don't make the bend. Take the antenna and move it about the back and sides of your phone while watching the signal meter. Eventually you will see the meter jump in strength. That means the new antenna is over the internal one which is receiving signal through the case from the external one. It doesn't work as well as the process in the video, but then some gain is better than no gain at all.

author

Cool, i'll have to try it out some time

author
ninjapants (author)2007-12-07

This looks a lotlike this wireless antenna hack on metacafe.
Obviously the lenghts are different for the different wavelengths, but otherwise it's pretty similar.
I'm not trying to complain, just think that some people who get to this instructable might like that video too.

author
Hoopajoo (author)ninjapants2007-12-07

Yeah, I was inspired by that video of Babblin5's. Basically, I used his idea of the screw to form the coil, but other than that the measurements are completely different. If you want to increase your WIFI range, definitely check out that video. I used it to increase the WIFI sensitivity on my work PC, and it works magnificently!

author
GorillazMiko (author)2007-12-06

cool! looks easy :)

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Bio: USAF - Spec. Communications, Telemetry & Data Networking, Microwave Networks, Aeronautics Interests: Metal working, Electronics and Botany (especially wild edible plants, "Feed the world with weeds") More »
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