I was this close in returning this product. I installed it up on the highest point on my single story house, probably 13 feet or so. From there I had a direct line of sight to a cell tower on a building about a mile away and got 4 to 5 constant bars on my cell phone, (in the house I'm lucky to get 2 bars and sometimes none for a few minutes). I used the supplied RG56 coax, and attached the antenna on my eve, which I was a little worried because there was metal flashing for my roof probably 9 inches from the antenna. Hooked everything up, placed the main unit in my central A/C closet, and fired it up. Nothing! Absolutely no improvement whatsoever. I opened up the A/C closet door, and yes I did get improvement, 4 bars when my cell phone was 2 feet from the unit. Closed the door, walked 5 feet away, went to 1 bar. Complete disappointment.
Upon reading all of these reviews, I decided to give it one last chance by upgrading the RG56 to some dual shielded RG6 I had left over while running my DirecTV. I also decided to put the antenna on some PVC pipe, so it was the recommended 2 feet from all metal (my flashing). I went to Lowes, got some 1/2 inch pcv pipe (which I cut to 2 feet), bought two end caps which I drilled two holes on the top of each using a 3/8 drill bit. I also went to the lamp section and purchased a Portfolio item # 045598 1" brass hollow core pipe. It turns out that RG6 perfectly fits through this small threaded pipe. I used this part to attach to the bottom end cap which I drilled out, to the supplied mounting bracket. I used some locknuts they had a Lowes to connect the parts (Portfolio unit # 036272). For the antenna, I just used one of the same Portfolio locknuts to secure the antenna on top which turns out to be the same thread size. Run the RG6 though the pipe, cut and crimp a connector, and attach to the antenna. From there, just prime and glue the whole attachment together using standard pvc primer and glue. Installed the antenna, ran the coax as before and attached to the unit. As soon as the units light turned green, 5 bars. I closed the A/C closet door, walked 10 feet away, still 5 bars! Amazing. Went 25 feet away way to the garage, at 4 bars with an occasional 5.
All I can say is DO NOT use the supplied coax, it's complete junk. Use at least dual shielded RG6. And installing the antenna on some pcv pipe was only 6 bucks worth of materials, so it can't hurt. I'd give the unit 5 stars if they knocked off a few bucks and just said to use some RG6. I'm a happy customer now.