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iOS 4.1 Restores Field Test Mode

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Original poster
Apr 12, 2001
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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. 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.

Article Link: iOS 4.1 Restores Field Test Mode
 

anubis

macrumors 6502a
Feb 7, 2003
937
50
Users with a poor understanding of the difference between linear-scale and log-scale need not apply.
 
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Dr Kevorkian94

macrumors 68020
Jun 9, 2009
2,139
34
SI, NY
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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chaosman

macrumors newbie
Aug 26, 2010
1
0
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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QuarterSwede

macrumors G3
Oct 1, 2005
9,492
1,574
Colorado Springs, CO
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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iZac

macrumors 68020
Apr 28, 2003
2,149
1,423
Shanghai
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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Dr Kevorkian94

macrumors 68020
Jun 9, 2009
2,139
34
SI, NY
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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coolfactor

macrumors 601
Jul 29, 2002
4,894
5,216
Vancouver, BC
iPhone 3G.

Oddly, the battery percentage doesn't show for me next to the battery icon.

My dBm is -90 where I am (inside a building).
 
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DigitalLifeDad

macrumors newbie
Nov 19, 2004
12
0
TIP: During Field Test Mode...tap the numerical figure to switch to the regular antenna strength, the traditional bar measure.

This only works during Field Test Mode.
When you hit the home button and it closes, that functionality no longer works.
 
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iShorty

macrumors regular
Jun 23, 2010
110
18
Nottingham, UK
TIP: During Field Test Mode...tap the numerical figure to switch to the regular antenna strength, the traditional bar measure.

This only works during Field Test Mode.
When you hit the home button and it closes, that functionality no longer works.

There's ways to keep the field test mode while using your phone.
http://twitpic.com/2mjo4u
 
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smileyborg

macrumors 6502
May 12, 2009
267
0
Yes go into Feild test tap the bars at the top so they change to DBS and then respring (hold the sleep button till it says slide to power off then Letgo and hold the home button). now the DBS will be at the top and just tap them any time to switch back to bars.

Excellent tip! Will keep it as a numerical measure for a few days and see how things look in different situations.
 
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VenusianSky

macrumors 65816
Aug 28, 2008
1,290
47
I just updated from 4.0 to 4.1, so I never had the "fixed" bars until now. From my apartment, it use to display full bars. Now I have only 2-3. Boy, was I deceived the whole time. I entered field test mode and get between -95 and -101. Oh well, calls work fine and that is all that matters.
 
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