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iOS 4.1 Restores Field Test Mode


Gizmodo reports that iOS 4.1 has reincluded the Field Test mode to iOS. Field Test mode allows you to get a numerical figure for your antenna strength rather than the traditional bar measure. To get to Field Mode:

- First, upgrade your iPhone 4 -- or any iPhone -- to iOS 4.1.
- Dial *3001#12345#* into your phone [and press Call].

Pressing Home will exit you from the Field Test mode. For reference, Anandtech provides a good discussion about bar strength and signal values. Since that article was published, Apple has remapped the signal strength to # of bar ratio. More negative numbers are worse, and Anandtech reports they were surprised they were able to hold calls with signals as low as -113db.

Most customers won't care about their numerical signal strengths, but the antenna strength changes generated a lot of publicity surrounding the iPhone 4 launch due to issues with new antenna system.

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19 months ago
Users with a poor understanding of the difference between linear-scale and log-scale need not apply.
Rating: 0 Positives / 0 Negatives
19 months ago
I still don't have it and I'm on 4.1 gm I go in and all I have is blank lines, but I can still tap the bars at the top and change them.
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19 months ago
people on other blogs are saying that death grip really affects db levels. And now we finally have a valid source of information rather than just "bars"
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19 months ago
That is what I'm talking about...a specific number to use. Not bars!
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19 months ago

I still don't have it and I'm on 4.1 gm I go in and all I have is blank lines, but I can still tap the bars at the top and change them.

The GM is exactly the same as the public release. I mean they're identical. Field test only shows the numbers, there is no more info unfortunately.

people on other blogs are saying that death grip really affects db levels. And now we finally have a valid source of information rather than just "bars"

You could display the numbers if you went from a jailbroken phone running a hack to display that in 3.1.3 or 4.0 to 4.0.1. It would keep it and show you the numbers instead of bars. So this isn't anything new really. It's just a much easier way.

Also, there is thread about this on MR already.
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19 months ago
Ignore this post, I forgot the star on the end.
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19 months ago
Should refer to "dBm" not "db" :)
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19 months ago

Not working in the UK.

"Error performing request
Unknown Error"

I may be wrong..


Works for me, db on one side, battery percentage on the other :)

Incidentally, I double tapped to jump out of the field test into another app and now the meter stays up. pushing the corner changes between bars and db.

(using a 3GS, was just curious)
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19 months ago
so does deathgrip destroy this thing?
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19 months ago

The GM is exactly the same as the public release. I mean they're identical. Field test only shows the numbers, there is no more info unfortunately.


You could display the numbers if you went from a jailbroken phone running a hack to display that in 3.1.3 or 4.0 to 4.0.1. It would keep it and show you the numbers instead of bars. So this isn't anything new really. It's just a much easier way.

Also, there is thread about this on MR already.


Just to clarify this is it:


And for the second thing u said u can have it that the DBS are showing and that u can tap them at the top just to switch back to bars I do it all the time:
http://db.tt/fJoViyJ

http://db.tt/AbF2OUw
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