Last week I tested — and lambasted — the Griffin ClearBoost case as the offspring of those “cell booster” stickers of yore. This touched a nerve at Griffin HQ and will encourage me to research this further with a fresh iPhone and a case. While I stand by my assessment that this is an RF interference device rather than a “booster,” I’m glad the folks at Griffin, the founder included, are giving my opinions a fair shake and performing further tests to ensure you, the readership, that their product works as advertised. In a sense, my opinion doesn’t matter. I just don’t want folks buying something that, if not all it claims to be, is at best a placebo and at worst a cause of RF interference.
Here’s some feedback from Griffin:
T-Mobile did say that if there is no 1900 MHz service available it will switch to 850 MHz without any roaming charges. Apparently they have cut deals with other carriers to allow for this. So you are correct there. However, it looks for its 1900 MHz service first. You’ll notice from your photo in the review (below) the number to the right of FQ is around 600 for all seven readings. If it were on the 850 service the FQ reading would be in the 100-200 range.
Here’s the link at the Griffin site that explains it further:
“If your iPhone is currently on the 850 MHz band, the FQ value will be in the 100-200 range. If the FQ value is in the 500-700 range, you are in a 1900 MHz area.”
As an aside, we’ve had a case for a little bit and notice improvements anecdotally (YouTube videos downloaded faster, calls with no bars, etc), but after your article I went on a quest this weekend. I travelled over 100 miles in urban areas, mountains and suburbs. In the 15 tests I did – on average – the case improved the signal by 24.6 dBm (or 3.5 dBm per tower) per test (that’s taking the seven readings in field test mode in 15 tests and averaging them). The stronger the signal the less it improved it, but when the signal had readings of over 100 without the case, it showed much bigger improvements. If you look at your photo below none of the readings are above 100, so you have a pretty strong signal. Of course, I’m just a PR guy and not an engineer, but I wanted to pass along that what you wrote really motivated me personally to test this case all weekend in all environments.