5-Minute Project Video: The Coffee Can Cellphone Antenna



Cellphones have been around for quite some time now; you would think that, by now, the technology would have evolved to the point where our homes would no longer be subject to cruel, phantom areas of poor reception. But alas, dense concrete, wire-mesh stucco and some kinds of metallic siding can still render your home an annoyingly cell-free zone.

Here, How 2.0 solder-meister Mike Haney shows you a quick and cheap method of using your phone's hidden antenna-out and the garbage from your coffee and cookie consumption into a workable solution for improving your cell reception at home.

13 Comments

Comments

Anonymous (imp...

Or you could get a new phone with a better antenna.

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GPE (imported)

The www.electrocom.com site mentioned in the video doesn't appear to be correct. It goes to some consulting firm.

Anonymous: I have a newer phone and where I live has very poor reception with the provider I use. An other provider has good reception at my home, but not elsewhere in the city, which is were I use my cell phone more. Tradeoffs.

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sherlock (imported)

Couple of comments:
1. You start out by removing the bottom of the coffee can. Then you show a different coffee can with the bottom in, and the Pepperidge Farm can with its bottom out. What happened?

2. Perhaps if you cut down on the lead-in diddly-bop stuff you would have had time to show us the Pepperidge Farm can for longer than 1/2 second so we could see the label and hear the name of the product.

3. Maybe the diameter of the hole in the side of the can is important? Never said what it was or how to make it.

You know, most people looking at this are not 14 years old. Think about it.

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The_Dark_Knigh...

Sherlock,

Which seems a fitting name,

some tips to help you on your way:

Question 1:
He says you must remove the bottom of ONE of the cans. so pick one. it doesn't seem to matter which.

Question 2:
The beauty of these internet videos are that if you don't catch something the first time you can go back, watch it again, and pause it if necessary. We can assume by the end of the video that the ""Mystery Pepperidge Farm Pirouettes" tin needs to be the same diameter as the coffee can. So when you are assembling these items just keep that in mind.

Question 3:
I would say the diameter of the hole is very important. I would say that it should be roughly the same size as the piece you are fitting into it. So if you have that piece, which you WILL need in order to complete this project, you can measure it and make the hole accordingly.

and finally, if you aren't 14 years old why would I, a 14 year old, need to tell you all of this?

ps. good work guy. The "electrocom" link does seem to be wrong but all in all an interesting project. I even enjoy the lead-in Diddly-Bob stuff. Gives it a lil flair! :)

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Marc (imported)

Neat video! You should link to a write-up of the science of how it works. How important is the can size? The hole location? Why? A supplementary in-depth discussion would add a lot to the video.

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Ford (imported)

If the copper is being used as the actual antenna and the can is just being used as a waveguide, then how long should the copper be? This is a pretty important bit of information that's not given.

0 out of 0 people found this comment helpful
Luby Sawkiw (i...

Good project! I used to be involved in ham radio and commercial broadcasting, so I can understand how the antenna can offer a signal gain. However, did Mike Haney say 97 millimeters from the end of the can? Did the 97 mm distance come from a formula or by experimentation? Using wavelength (meters) = 300/Freq. (mhz), wouldn't a distance of 97 mm work out to a frequency of around 1550 mhz? Didn't he say cell phones are up around 1900 mhz? I believe the idea is to put the pickup stub 1/2 wavelength from the closed end of the can, so that the reflected wave will reinforce the next arriving wave. Using 1900 mhz, I get a wavelength of 158 mm and a half wavelength puts this distance at 79 mm, not 97mm. I am not sure of the exact range of cell frequencies being used, but in my radio days working with antennas, I sure enjoyed figuring, measuring and tinkering and then finding out that some other solution worked better in actual practice. The project is a great idea.

Lubi

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mike (imported)

Ugh - you guys are right - the link was supposed to be shown as http://www.electro-comm.com - I think I only said it out loud and the producers just put it in that way. Sorry.

For a full parts list and diagram, see here: http://www.popsci.com/popsci/how20/4003b56ed315e010vgnvcm1000004eecbccdrcrd.html

Also, this project originally came from Mike Outmesguine, the wireless guru behind SoCalWUG and the author of Wi-Fi Toys. I can attest that he's done the math and tested the design.

Finally, Sherlock, sharp eye: we did do a switcheroo in filming -- because of time and production constraints we soldered together one set of cans and then switched to another set that had the hole pre-drilled. Such are the limitations of video.

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Breather Guy (...

Mike:
Eye protection is important when soldering.
For 900 Hz or 850 Hz phones what would be the best distance?

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jd (imported)

Couldn't a piece of metal ducting be used instead of the cans? The length can be cut, and the diameter altered. Is the diameter critical? Does it have to be metal? I'm guessing the reflecting bottom might need to be???
I'm thinking of building one for my apartment dwelling daughter. Nice video, but an article explaining why it works would have been nice. This is popular SCIENCE magazine - not popular tinkering! haha

0 out of 0 people found this comment helpful
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