On one of my recent SOTA (Summits on the Air) trips a few weeks ago, I made up my mind to give one of these Generation X signal boosters a go. They are not expensive, but I could not really find much of value on the net about how good or bad they were.
(I should point out that I have no association with the sellers of these products – I just bought some).
Do they work? I think they do. Here is a pic with two installed in a Samsung Galaxy S2
I tried installing them both horizontally and vertically. It appears a vertical installation (as pictured) has more effect. As can be seen, I installed 2 of them. Most of the improvement was with one installed, but the second still had a small noticeable improvement. I would guess 2dB. Better than nothing!
How much effect? I would say about 6dB to 8dB. In terms of bars, this is about 1 and half bars. It is not always easy to tell the difference because there are many factors with mobile networks. The effect is most obvious in areas where the signal is very marginal, say at the edge of a service area, or well within a building. It is here where the phone and the network may be limited in choices such as handover to a better tower. The tower may already have the phone on max power level.
There is one spot in the church I go to on Sundays where the signal is right on the edge. A Bible app I use has to pull data from a server over the mobile phone network. I am generally kicked to 2G, and struggle to pull any data. With these things installed, I was able to maintain a solid 3G signal. A friend installed it in a Samsung Galaxy S3 and was able to maintain a phone call for the first time ever in parts of his house where he typically can only get SMS service. He has had to go outside or even up the street to get reliable phone service in the past.
I also have noticed improvements in rural areas. The signal is basically stronger for longer. Of course, once right out of service area, you still won’t get anything. In urban areas, I notice that it is often changing between towers at much higher signal levels than before.
Overall, at least in terms of my Galaxy S2 and my friend’s Galaxy S3, it appears that this device was worth it. As for the non SP1 Generation X, I have not tried it and cannot comment on it.