| Explained: Frequency Gain, Cell Phone Signal Distance, | | | | Your Frequency : To determine whether you need a |
| Cell Phone Frequencies, Finding your Cell Phone | | | | 800 or 1900 MHz yagi, go to and click "Find Your |
| Tower Location | | | | Frequency". |
| The Cellular Yagi Antenna | | | | Your Tower Location: Since the yagi antenna needs |
| One of the most frequent questions we get is about | | | | to point towards your service providers tower, you |
| the cellular yagi antenna, which is used in rural/remote | | | | need to know where it is. There are three easy |
| locations to get a strong cell phone signal, extend cell | | | | ways to find the cell phone tower location. They are: |
| phone signal, and works with most cellular wireless | | | | 1. If the location where the yagi is to be used is not |
| repeater systems for buildings. | | | | blocked by trees or taller buildings around it, just walk |
| Like a lot of things on the internet it gets confusing | | | | around the building's perimeter with your cell phone. |
| going from site to site with each one seemingly | | | | The side of the building with the strongest signal |
| giving different information and claiming there's is the | | | | reading is usually the direction of your tower. |
| best. We've taken the time to explain it, without | | | | 2. Call your service provider's customer service and |
| trying to make an engineer out of the reader. | | | | ask. If they won't give it to you, don't argue. Simply |
| This will allow you to compare yagi's "apples to | | | | hang up and radial. The next person is likely to say |
| apples". | | | | they are happy to give the tower location to you. |
| The yagi antenna : The most common directional cell | | | | 3. Mount the antenna, connect it into the cell phone |
| phone signal booster antenna is known as just the | | | | or laptop air card's external antenna port, if it is |
| yagi or yagi cell phone antenna. It is named after its | | | | equipped with one. Then turn the yagi in 10 degree |
| inventor, who created it in 1908. It is the antenna of | | | | increments until you have the strongest signal. To do |
| choice with most cellular signal professionals when | | | | this you will need the correct adapter that allows the |
| needing high, consistent performance. | | | | antenna's cable to plug into the cell phone or air card. |
| Yagi Antennas are generally used as outside, or | | | | To find the correct antenna adapter or to view |
| "donor" antennas. Yagi's for cell phone use are | | | | examples of cell phone external antenna port |
| normally single band, meaning they are engineered | | | | locations Click Here. |
| and made to work for 800 MHz or 1900 MHz, but | | | | NOTE: You cannot hold a yagi antenna to attempt to |
| not both. Some Internet sellers claim to have dual | | | | tune it in. To tune the yagi antenna, it should be |
| band yagi antennas, but the ones tested by two | | | | mounted on a metal pole where you plan to |
| major antenna manufacturers we deal with have | | | | permanently use it. You must completely remove |
| found that one of the two signals suffers. This is | | | | your hand each time you turn the yagi and wait 5-10 |
| because antennas for lower frequencies need more | | | | seconds before looking for a signal strength change. |
| surface area than higher frequencies. | | | | Using the phone test mode can help you to find your |
| A yagi antenna is made with a number of vertical | | | | cell phone tower location / direction as well. |
| bars, or elements mounted onto a longer horizontal | | | | Phone Test Modes : Many cell phones can be put into |
| bar. A drawing of a typical yagi antenna is shown | | | | "field test" mode for signal strength testing. This |
| below: | | | | allows you to read the signal strength in decibels |
| | | | instead of bars. You can get to "field test" mode |
| Yagi antennas cannot receive or transmit a signal | | | | with just a few key strokes. |
| from the side or rear, only the front.dBi vs. dB: These | | | | NOTE : The signal strength is shown as a negative |
| are designations used in describing the amount of | | | | number; it will have a minus sign in front. Therefore, |
| gain an antenna offers above the current signal | | | | the lower the number, the stronger the signal. So -75 |
| strength of the device to be used, like a cell phone. | | | | indicates a stronger signal than -85. |
| dBi is always two numbers higher than dB. Therefore, | | | | To find the menu to put your cell phone or PDA into |
| a 13 dBi antenna has the same gain as an 11 dB | | | | field test mode go to then click "Technical Support". |
| antenna. The designation used is simply at the | | | | Signal Distance : If mounted properly, with |
| discretion of the user. This is important to know so | | | | line-of-sight to the signal (not necessarily the tower) |
| that you can compare "apples to apples" when | | | | you seek a high gain yagi antenna will send and |
| comparison shopping. | | | | receive signals for miles. |
| Gain: Because of the nature of radio frequency | | | | You can expect even higher performance when a |
| signals most yagi antennas generate a maximum of | | | | high gain yagi antenna, like the 13 dBi gain Wilson |
| 13 dBi gain. Additional gain achievement quickly | | | | 301111 is used with a Wilson direct connect 3 watt |
| reaches a point of diminishing returns. | | | | amplifier . |
| Example: A typical 800 MHz 13 dBi yagi is about 32 | | | | Example: Our customers successfully use the type |
| inches long. To achieve a 2 dBi increase, to 15dBi, the | | | | applications 25-30 miles offshore in the Gulf of Mexico |
| surface area (length) has to be approximately | | | | and for numerous other remote applications. |
| doubled. | | | | Yagi antennas are often the antenna of choice when |
| Therefore, beware of claims of more than 13 dBi for | | | | using a wireless repeater system like the Wilson |
| yagi antennas made for use at the 800 MHz and | | | | 801245 Small Office Home Office System and the |
| 1900 MHz frequencies. | | | | Wilson 801106 wireless repeater system for large and |
| Applications: Yagi antennas are generally pole | | | | or weaker outside signal applications . |
| mounted and elevated, to get over obstacles that | | | | Type of Coax Cable Needed: The type and length of |
| block the line-of-sight. One reason they are so highly | | | | coax cable that should be used with any cell phone |
| recommended is that the high gain allows them to be | | | | signal booster antenna, air card and/or amplifier is |
| elevated without causing significant gain loss do to | | | | dependent upon the frequency that the antenna |
| the use of longer lengths of coax cable usually | | | | operates. The factors to determining the type and |
| needed to pole mount the antenna. | | | | length of coax cable that should be used are as |
| Example: LMR400 coax cable (Wilson 9913) loses four | | | | follows: |
| tenths of a dB per ten feet at 850 MHz. So a fifty | | | | 1. RG8X Coax should not be used in 1900 MHz |
| foot length loses a total of 2 dB's. 9 dB is still available | | | | applications. It should not be used in lengths of over |
| to the connected device (cell phone, etc.) as the net | | | | forty feet when used at 800 MHz. It is double |
| gain from a 11 dB gain antenna. | | | | shielded, is considered low loss cable, but it still loses |
| The extra gain of the yagi is necessary for many | | | | 7.7 dB per one hundred feet at 800 MHz. |
| rural and remote applications. Most repeater systems | | | | LMR400 Coax should be used with all 1900 MHz |
| use this cable to get as much signal to the amplifier | | | | applications, most wireless repeater (booster) |
| as possible. | | | | systems and lengths of over forty feet at 800MHz. |