Directional yagi antennas, unlike omnidirectional antennas, must be aimed in order to receive the strongest signal from your cellular carrier(s). Here are some things to know:

  • Most directional antennas can cover about 15% of the horizon (between 50 and 60 degrees), so your aiming doesn’t have to be laser-precise. Being off by a little will still work just fine.
  • In almost all situations, the antenna should be level and even with the horizon. Do not attempt to aim the antenna up over a roof or nearby obstacles.
  • You should attempt to aim the antenna before deciding where to permanently mount it.

Even if you know exactly where your carrier’s tower is located, it’s still a good idea to go through this aiming process.

Aim the Antenna

First, temporarily setup your signal booster system by running the LMR400 coaxial cables through doors or windows, connect everything together, and power on the system. To aim the antenna, you’ll ideally need two people. One person will stay inside with a cell phone from each carrier that you want to support. The phone(s) should be in Field Test Mode, so you can take decibel signal readings, which are more accurate than bars. Place the phone(s) on a table or other surface between 10 and 20 ft. away from the inside antenna and leave them in the same place until the aiming is completed. If it’s a directional inside antenna, be sure that the front of the antenna is aimed directly at the phone(s).

Measure the Signal Strength

  1. Start with the outside antenna aimed in one direction. The person inside should then wait 60 seconds and then record the signal readings from the phone(s).
  2. Next, rotate the outside antenna 45 degrees or 1/8th of the way around.  Once the antenna has been rotated 45 degrees, the person inside should again wait 60 seconds and then take another set of signal readings.
  3. Repeat this process until you’ve aimed the outside antenna in all 8 directions and have 8 sets of signal readings.

Once you have the signal readings, you’ll want to find the direction that gave you the strongest readings for all of the carriers that you want to support. If you took decibel readings, then look for the readings that are closest to 0. For example, a -70 dB reading is better than a -90 dB reading. The stronger the signal, the more coverage you’ll get from the system.

If, while testing, you find that there are warning lights on the booster, consult your owner’s manual for information on what caused the warning. 

The warning light will be on if oscillation (feedback) is present, try retesting in that direction but increase the separation between the inside and outside antennas.

If the warning is due to overload (too strong of a signal coming from a nearby tower), then the aiming process will still work correctly by helping you find the direction where the system performs the best.

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