Analyzing Apple’s iOS 4.0.1 Signal Fix & Antenna Issue
anandtech.com
anandtech.com
"there’s more dynamic range in these numbers too. Previously, the absolute lowest value any iPhone would report was -113 dBm. With iOS 4.0.1/4.1, the value is now a shockingly low -121 dBm. In the iPhone 4 review, I talked a lot about how although the phone is prone to dropping signal from being held wrong, it was measurably more sensitive in weak signal areas. I was shocked that calls and data worked seemingly unfazed at -113 dBm. It seems as though this increased 8 dBm of range below -113 dBm was meant to show really how much more sensitive the radio stack is - it undeniably is more sensitive. Both Anand and I were able to hang onto calls all the way down at -121 dBm."
On another note, I posted this article to HN 13 hours ago. Since this was my first submission I am wondering... does anyone know why my submission withered away, and this one rose to the top?
Here is my submission: http://news.ycombinator.com/item?id=1518958
Yes, human body can conduct electricity, but your conductivity will depend on amongst other factors, your gender, age, body fat percentage, hydration level, etc. A piece of copper wire is not going to have these problems. So show us once and for all what's going on.
paperclip vs iphone 4
The results of doing a bunch of measurements like this could make it much easier to answer questions like: What is it about your hand or your grip or whatever that determines how much you impair reception on your iPhone? How much of the problem would go away if you put various things (kapton tape, rubber bumper, etc.) between the antenna and your hand?
Just playing around with actual human hands can give some information of that sort, and if you're only going to do a small amount of investigation you probably get more information that way. But for a deeper understanding of what's going on, you'd want to be more scientific and try harder to decouple different failure mechanisms.
(Of course talk is cheap. I haven't done any of that. Not least because I happen not to have an iPhone.)
It is, without doubt, #1. Any confusion stems from the variety of ways in which it can fail to happen (variable conductivity of people, for one), or fail to have dramatic results (being in an area with strong signal).
If you're sufficiently conductive, there's a good chance you can reproduce the problem by walking into an Apple store and trying your hand. That's what I did, and there was a dramatic difference between bridging both antennas with just an inch of finger vs covering the left antenna with as much palm as possible. That wiped out any remaining skepticism I might have had.
EDIT: Also, we don't know if the steel is insulated. Has anyone tried to measure its resistance? For all we know it is insulated and the problem is (2).
“Gizmodo reported (and iFixit followed up) on some users claiming that newer iPhone 4s had a different coating on their stainless steel band that mitigated the signal attenuation issue caused by tightly holding the phone.”
“We found an iPhone 4 produced in week 28 of 2010 (digits 4 & 5 from the left of the iPhone 4’s serial number indicate production week) and took a multimeter to it. There was no measurable difference in resistance between it and our older iPhone 4s. In other words, the band was just as conductive.”
But, of course, even if you do something that fixes #1 completely, there will always be people saying "Boo, Apple hasn't fixed the problem! When I hold my phone like this, I get less signal, just as I did before!" -- when in fact the same would be true whatever phone they used.
I've banged on about this on previous threads (sorry), but a free bumper is my least preferred resolution.
Since I dislike phone cases, it's essentially saying I can't have the phone I wanted. Instead, I have to choose: faulty or ugly.