QUOTE(objectifyme @ Jun 26 2010, 02:41 PM)
Okay, I don't get it. What does that have to do with the antenna? Sure, it uses a different chip. But if the antenna is the problem, it doesn't really matter what chip it uses, does it?
Note: No intention of stirring up an argument. Just looking for answers.

I saw your comments so I thought of giving you further insights into the problem. Actually the chip does play a major role in signal quality and reliability during calls/connection. With IC advancement and RF design, efficiency would be better. The iPhone 4's RF chip probably receive 1 full year of innovation since 3GS so it could be more sensitive to signals kinda like how a new GPS chip is better and more accurate than previous one.
Also new IC would allow new features or better control by firmware programming. As a result, handling of 2.5G/3.5G radios would be better especially the transition from one radio to the other when you move around. Also the handling of transfer from one cell to the other. It is typical for the phone to switch from 3G to 2G when 3G signal is weak and only to switch back to 3G when signal improves (due to power consumption and signal quality). With the typical antenna placement on the bottom of the phone (due to SAR requirements), this problem is amplified. Most dropped calls happen here when the phone switches radio. However, the base station also play a role in the handling of switching. And we all know AT&T's infrastructure is dodgy hehehe, so this is nothing new. This is also a limitation in the current mobile infrastructure we're using now.
Another factor in dropped calls is when you move from one cell to another cell. The phone needs to register to the new station and service is transferred. MOst of the time this is transparent to us. Sometimes handling isn't smooth and you will get dropped calls. Anyway going back to the RF IC, there was suspicion that the IC used on 3G/3GS was flawed. So it does play a role in this issue. The antenna design serves to improve the efficiency of the whole setup and is just one part of the problem. By the way, there are reasons why antenna 'should be inside' the case. Hehehehe... There's one way to improve signal quality via antenna design. That is to adopt a 3D plane antenna. A good example is Acer's 3D WIFI plane antenna used on most of its laptop. The isotropy of radiation and its pattern is more evenly distributed. But you need more space, something iPhone doesn't have.
Before I forget, switching policies does make a difference too. For example, 3G preferred or 2G preferred or 3G only/2G only, etc. The policies are usually set in the interest of power consumption (due to near far phenomena of GSM radios) and signal quality vs signal strength. Sometimes strength doesn't mean anything when the quality is low.
These are some of my insights and 2 cents.
QUOTE(stringfellow @ Jun 26 2010, 04:56 PM)
If your SIM is the older version, then yes, you will have to cut through the golden area of the chip. Latest simcards will have the gold chip size smaller and after trimming it down, it will still be possible not to damage any of the gold chip part.
Yes, you can cut into the 'golden area' or otherwise known as the module tape/contact patch as long as you don't cut into the module hidden underneath it. The contact patch is just a larger area and can be trimmed. The SIM friction pins in the phone is electrically compatible and only needs a small area of contact to work. There is a lot of tolerance to play around.