Stealth X6 60dB 6-Band 3G 4G LTE Extreme Power Building Booster Kit--MCT Connectors Without Antennas

STEALTH X6 4G LTE Customizable Booster

  • 60 dB gain
  • Build a kit by choosing antennas and cables with MCT connectors
  • Covers up to 4000 sq. ft.

Note: Does not support Sprint bands 26 (lower 800MHz) and band 41 (2500 MHz)

BEFORE USE, you MUST REGISTER THIS DEVICE with your wireless provider and have your provider’s consent. Most wireless providers consent to the use of signal boosters. Some providers may not consent to the use of this device on their network. If you are unsure, contact your provider. You MUST operate this device with approved antennas and cables as specified by the manufacturer. Antennas MUST be installed at least 20 cm (8 inches) from any person. You MUST cease operating this device immediately if requested by the FCC or a licensed wireless service provider.

All SmoothTalker BBUX660XH kits include

Stealth X6 60dB Amp Only With MCT Connectors

SKU: BBUX660xaa

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120V Wall Power Supply


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Description Type Link
User Manual PDF Download

Stealth X6 home and building boosters increase the cell phone or mobile device incoming and outgoing cellular signals. They can help eliminate dropped calls and increase battery life and data speeds with simultaneous boost of both voice and data services. The LED console display signal level indicators help make installation quick and easy.

The Smoothtalker Stealth X6 Building Boosters are the most technologically advanced wireless cellular signal boosters made. They feature proprietary "Stealthtech technology" that prevent shutdowns from poor antenna placement and changing environment.

This advanced technology protects the cellular towers from overloading and provides maximum signal coverage to the to the mobile device. Stealth X6 boosters are recommended for areas located up to 35 mi from the cell tower.

How it works:

First you should determine the signal strength outside the building. Then see the chart below to see how much area you can expect to cover.

In locations where the outside signal is weak, a higher gain or higher power model booster unit will be required in order to increase the coverage area.


If the outside signal is fair to good, the Stealth X660 model can cover up to 4000 sqft. However if the outside signal is poor the coverage area will be reduced and in cases where the outside signal is extremely low the coverage area could be only a few feet from the inside antenna.

(See coverage area and signal strength charts below to help determine which model you need)

NOTE: Stealth X6 boosters are recommended for distances up to 35 mi from the cellular tower.

Find your outside signal strength

Use the signal bar indicator on your cellular device to determine the approximate outside signal strength as per the chart below. Note: Even if your device shows no bars or "no service" it is possible that there is enough cellular signal for the booster to achieve communication with the network.

Assessing your outside cellular signal level

Installation and Setup

  • If mounting the antenna outside is not possible place it on a window where the strongest signal is indicated on your cellular device.
  • Inside and outside antennas require as much distance (separation) between them as possible to avoid feedback loop (oscillation). When feedback occurs the booster automatically lowers its gain which reduces coverage area. If this occurs you should turn off the unit and try to relocate the antennas to be further apart.
  • Flashing green LED lights indicate gain reduction. If the green lights on the booster are flashing, please refer to the user manual for detailed instructions on how to interpret the flashes.
  • Perform a test installation with the booster kit before drilling any holes in walls to ensure that you have the correct booster kit model which achieves the desired coverage area.



Smoothtalker proprietary STEALTH TECH® technology amplifiers and boosters automatically control power and gain to eliminate feedback loop (oscillation) and strong signal overload from nearby towers. These automatic functions can reduce gain which will be indicated by flashing green gain LED lights on the booster indicator panel. See below steps to ensure proper installation and achieve maximum coverage area.


Gain reduction due to Feedback Loop Oscillation :

a) This type of gain reduction is caused by the antennas being placed too close to each other (Figure 1 below) which creates a signal feedback loop. If you increase the distance between the inside and outside antennas either vertically and or horizontally it will increase gain and provide a larger coverage area.

Gain reduction due to Strong Signal Overload (caused when you are located close to a cell tower)

b) If strong signal is coming from your own celllar service provider, gain reduction is OK and the coverage area should not be affected. There is no need to make any adjustments to your installation.

c) If the strong signal is coming from a cellular tower which is not your own service provider, you may experience unwanted gain reduction. In this case you can try to increase your gain by moving the outside antenna to a different location which points more to your own cellular provider tower or use a Smoothtalker Beam directional antenna which points directly at your own cell tower. (Note in some cases this may not help if all the cell towers are located in the same direction or line of sight or very close to each other).

Determining if gain reduction is caused by Strong Signal Overload or Feedback Oscillation :

d) Strong Signal overload check: Turn off the booster, remove the inside antenna and turn on the booster. If the green gain lights are flashing it means there is strong signal present and you should follow the steps in paragraph b andc above.

e) Feedback Loop (Oscillation) check: once you have determined that there is no Strong Signal Overload gain reduction (per paragraph d above), then connect both antennas to the booster and turn it on. If the gain lights are flashing it means there is feedback loop oscillation present (Figure 1 below) and you should follow the steps in paragraph a above to eliminate any oscillation.