I’ve spent today with Daniel Lim (SlashGear); Andru Edwards (Gear Live), Jon Westfall (Android Thoughts), Steven Hughes ( & Boston Pocket PC), Brad Sams (Neowin), at the Cedar Park, Texas location of ETS Lindgren. I’ll have a full article about the things we saw and what I learned about this fascinating company a little bit later, but I couldn’t wait to tell you about an experiment they conducted for me.
As you may recall, Larry, Dan & I recently reviewed the Element Case Vapor 4. All of us agreed that it was easily one of the most beautiful cases we had ever used, but we all experienced a significant signal drop when our iPhones were in them.
One of the things that ETS Lindgren is able to do is scientifically measure the antenna strength of a mobile phone inside one of their isolation and testing chambers, in this case the ETS-Lindgren Model AMS-8923 Over-The-Air Test Lab.
I asked them to test my iPhone without any case on, and we were able to establish a control of 26.8015 dBm as its antenna strength. With the Element Vapor 4 case on the iPhone, that number dropped to 7.706 dBm (!!!). When you consider that every three dBm is a 50% drop in signal strength, and that for every next three dBm you have to remove 50% of the previous remainder, we were told that figure roughly translates to a loss of 99% signal strength. No wonder I couldn’t make or receive calls consistently when my iPhone was in the case!
More interestingly, the naked iPhone went from 26.6917 dBm (we retested it because its battery had dropped and the phone was warmer from being in use) to 28.2659 dBm when it had the Apple Bumper case installed — which means it got an increase in signal strength of roughly 15%!
The moral of this story? Not all bumper cases are created equally. The Element may look fantastic, but I now have scientific proof that it will just about kill your iPhone 4′s antenna strength. Your best bet is to buy an Apple Bumper or another similarly designed, non-metal case; you may even see a signal improvement!
Update: Here is the video Andru, from GearLive, made of the process – complete with comments from ETS Lindgren Engineers: