How does the Cel-Fi Pro Booster work?

The Cel-Fi Pro consists of two units. There is the "Window Unit" and the "Coverage Unit".

The Window picks up the weak mobile signal from outside, either using it's own built in antenna, or from an external antenna connected to the unit by a cable.

The Window unit then sends this to the Coverage unit located further away and indoors. Normally the connection between the two units is by built in 5GHz WiFi, but there is an option to connect the units by cable.

Once the Coverage Unit receives the signal from the Window Unit it re-transmits this as a strong mobile signal - getting you from 1 bar (or even less at times) to 5 bars!

A mentioned the Cel-Fi Pro can work in two ways, using ir's own internal antennas, or being fed a signal from an external antenna.

The internal antennas of the Window unit are a high tech "Fractal" antenna and are really good at pulling in a weak signal. So if you have a spot in the building that get's "some" signal, simply locate the Window unit of the Cel-Fi Pro there.

The best place for the coverage unit is as far away as possible, whilst still maintaining a good link to the Window unit. This is easy to figure out as the display on either unit will tell you how good this link is.

It's amasing how often we find people convinced they will need an external antenna only to find the built in antennas are good enough to get a boost up to 5 bars.

Of course if there's no spot in the building with enough strength simply place the Window unit where you can bring a cable indoors from outside and connect up!

If using an external antenna there are 3 "options".

Where the reception is pretty good up on, say the roof, use an Omni (picks up all around) antenna. But if the signal is weak use a directional antenna like the LPDA to really focus in on the mobile signal available. In really weak signals a "Yagi" directional antenna may give better results.

To get the best "Boost" it is important that there is as much separation as possible between the antenna picking up the signal (The Window unit, Omni, LPDA or Yagi antenna) and the coverage unit. The coverage unit will push out the best signal when the Window Unit doesn't pick this up along with the external signal.

But as mentioned, most people are pleasantly surprised to find they don't need an external antenna in buildings with slight/marginal reception in one or two spots, and then find a convenient location for the coverage unit.

In some respects it's easier to place the coverage unit where an external antenna is used, so whilst needing an antenna and cabling the end result is often more flexible.

1 bar to 5 bars in 5 minutes - it really does happen!




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  • Hi guys I live in the mountains of Victoria and I am one of the 3% that does not have coverage. My phone and iPad are with Telstra and they work on the windowsill but don’t move them. If it’s cloudy forget it. Does you system require power and I can mount it outside on the veranda post or done the shed on the wall, maybe two units.
    I also don’t have tv cause of the same reason.
    If you like to look at the coverage map I am at the 3nd of wintles road mount best 3960 vic
    Not desperate but it would be good to have a usable system. Can these units also be mobile cause nothing works in the car either whilst traveling the hills.
    I await your responce kind regards Geoff

    Geoff monson on
  • Reception at 163 Wonga Road==a piece of that part of outback Australia that does not get(ever get) reception. One Chap that lived here was on emergency medical call and even with a booster had to leave to get reception from his hospital of employ … Alan Stone

    Alan Stone on
  • Hi to all at Boosters for Mobiles
    Just wanted to say thanks for your great product and equally great customer service.

    I purchase my Celfi Go with the Yagi antenna in December 2017. We were going to camp on the western beaches of Fraser Is where the mobile phone service ( even Telstra) is notoriously unreliable – varying from 1 to no bars most of the time.

    When we arrived I set up the system in about 20 mins. Less than 5 mins later my iPhone 6 and my iPad both had 4/5 bars of service. Incredible!
    And amazing every other Telsta phone used within about 10 m also benefited from the improved signal. But I’ve saved the best to last. When we got home the poor mobile service in our home was also a thing of he past.

    Thanks guys, your equipment has changed our lives.

    Cheers Dave

    David Olds on

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