Make a cell ‘cantenna’

Boost your signal using only metal cans and a few inexpensive parts.
A diagram for making a cellphone "cantenna."
It's a fairly simple process.

This story has been updated. It was originally featured in the November 2006 issue of Popular Science magazine and involves outdated technologies and services. For current advice, check our regularly updated stories about how to fix spotty cell service in your home or how to get internet to every corner of your home.

Savvy wireless-web surfers have long built antennas out of Pringles cans to increase faint WiFi signals. Cell calls also travel by radio waves, so I modified the cantenna design to work with cellphones. Pulled together from tin cans, copper wire, a radio-frequency connector ($10; electro-comm.com), and a phone-specific cable ($15; alternativewireless.com), the cantenna works like a loudspeaker, directing waves through the wire inside to your attached cell.

  • Project: bump up your bars
  • Time: 1 hour
  • Retail cost: $44
  • Difficulty: easy | | | | | hard (Editor’s note: 2/5)

The can’s dimensions tune the antenna to 1,900 megahertz, a common cell frequency. (The others are 800 MHz and 850 MHz.) To find out if there’s a 1,900 MHz tower near you, go to wirelessadvisor.com. Then simply attach your phone and point the open end of the cantenna toward the tower, with the connector facing the bottom. Move the can around for the best signal—you should get at least an extra bar or two. Use a Bluetooth headset to roam your house freely, enjoying cleaner calls with some cookies and a cup of decaf.

Parts

  • MJB Coffee: $3.50
  • Pepperidge Farms Pirouette: $6
  • Copper wire: $1
  • N-female panel connector: $10 (RF Industries part No. RFN-1022)
  • Connector adapter (if needed): $8.50 (RF Industries N-male to FME/TNC/etc., depending on pigtail type)
  • Cellphone pigtail: $15 (depends on phone model)

Instructions

1. Attach two cans 100 millimeters in diameter (one bottomless) with solder or copper tape. The total length should be 310 millimeters.

2. Solder a 39-millimeter copper wire to the connector, and drill a hole for it 97 millimeters from the closed end of the cylinder. Screw it in place.

3. Attach the phone-specific pigtail to the cantenna and plug it into your phone’s antenna jack (usually in back, covered up by a piece of rubber).