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Original post by: Craig Sherman ,

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This is an update to the never ending quest to figure out the antennas on the LG V20, and in my case specifically the H918 (T-Mobile) but the others are probably similar:

This is a list of what I know for a fact and have confirmed:

—  WiFi: 2.4 GHz and 5 GHz antennas are located inside the TOP bumper of the phone ONLY.

—  Cell Data:  There are RX antennas on both the top and bottom bumpers, and the radio is a “diversity” receiver.  A diversity receiver has more than one antenna (in this case 2), and it switches from one to another to get the best signal.  It is constantly monitoring the signal quality and strength on each at the same time and uses the best of the two for receive.

My To Do list:

— Test my theory that the TX (Cell Data) mostly uses the bottom bumper.  I suspect that one or more bands may use the top one for TX as well.  Figure out for each band (2, 4, 12, 66) if the TX is on the bottom or top.

— Determine exactly what each spring loaded terminal on the top and bottom of the phone where it connects to the bumpers is used for.  Another words, if one of them is for this band, or that band, or if its combined, etc.

I will be using a  HACKRF SDR and/or a SDR USB dongle in my quest to figure out the transmit stuff.  There is a secret menu that can be accessed if you have Android 8.0 on the phone where you can turn bands on and off.  All bands are listed, but the phone will only work on the ones that the carrier allows, even if its unlocked.  They blow “fuse bits” in the radio to disable bands that they don’t support.  That is why you can use an unlocked phone with another carrier if its the same type of service (CDMA or GSM) and then get horrible data speeds.  The voice connection will always fall back to GSM instead of LTE - just a fact I learned the hard way.

The secret menu can be accessed from the phone dialer with the following code:

277634#*#

You cannot brick your phone with those settings, but you can make it not work properly, or at all.  A re-flash using LGUP and a KDZ file will always put the secret settings back to factory default, and of course wipe all your data.

If anyone has any questions or ideas, please leave me a message here or at K4MMX.1@gmail.com

Craig

Status:

open