mrochester
macrumors 603
Hi all
It's finally occurred to me that the iPhone 4 now has a field test mode which actually gives you a more useful reading when it comes to comparing signal, and as I have another phone sitting right next to the iPhone on the same network, also with a field test mode, I can compare.
Without touching either device I have 3G signal, and both are around the -97dBM mark.
When I pick up and hold the iPhone as in this picture http://******************/assets/images/resized/0001/9797/19797v1-max-250x250.jpg (which is how I hold my phone as I'm navigating around it with my right hand) the signal strength goes down to -120dBm, and at this point drops to 'no service'. When I hold the iPhone 4 in the same way, but in my right hand, the signal drops to about -106dBm and retains services.
When I hold the other device in the same manner (the antenna on this other device is also at the bottom of the phone), the signal strength drops to -103dBm, and it retains service.
So consistent with Consumer Reports' findings, when held with the lower left seam covered, the iPhone 4 drops considerably more signal that other competing devices.
In addition, without even holding the iPhone 4, if I put a fingertip over the lower left hand seam, the signal drops to the same -120dBm as when held.
It really can't be anymore conclusive than that. The left hand seam on the iPhone 4 is a major weakness in the antenna design. The signal deterioration by touching that one spot is so severe that those of us in marginal signal areas will be left with 'no service' if that spot is touched at all.
Based on the iPhone actual signal to number of bar graphs, the iPhone 4 can go as low as -121dBm before loosing signal. With touching the seam on the lower left causing a loss of 20dBm, this means people who are in the -90dBm or better range probably won't be able to make their phones lose signal completely.
It's finally occurred to me that the iPhone 4 now has a field test mode which actually gives you a more useful reading when it comes to comparing signal, and as I have another phone sitting right next to the iPhone on the same network, also with a field test mode, I can compare.
Without touching either device I have 3G signal, and both are around the -97dBM mark.
When I pick up and hold the iPhone as in this picture http://******************/assets/images/resized/0001/9797/19797v1-max-250x250.jpg (which is how I hold my phone as I'm navigating around it with my right hand) the signal strength goes down to -120dBm, and at this point drops to 'no service'. When I hold the iPhone 4 in the same way, but in my right hand, the signal drops to about -106dBm and retains services.
When I hold the other device in the same manner (the antenna on this other device is also at the bottom of the phone), the signal strength drops to -103dBm, and it retains service.
So consistent with Consumer Reports' findings, when held with the lower left seam covered, the iPhone 4 drops considerably more signal that other competing devices.
In addition, without even holding the iPhone 4, if I put a fingertip over the lower left hand seam, the signal drops to the same -120dBm as when held.
It really can't be anymore conclusive than that. The left hand seam on the iPhone 4 is a major weakness in the antenna design. The signal deterioration by touching that one spot is so severe that those of us in marginal signal areas will be left with 'no service' if that spot is touched at all.
Based on the iPhone actual signal to number of bar graphs, the iPhone 4 can go as low as -121dBm before loosing signal. With touching the seam on the lower left causing a loss of 20dBm, this means people who are in the -90dBm or better range probably won't be able to make their phones lose signal completely.
