R6800 Transmission Power max 6dBm

Installing and Using OpenWrt
1

OpenWrt SNAPSHOT, r16719-b993b68b6c

I just flashed openwrt on my Netgear R6800 but the transmission power seems to be maxed at 6dBM. I tried changing the country but it stays the same here are the results of iw list

    Band 1:
            Capabilities: 0x1ff
                    RX LDPC
                    HT20/HT40
                    SM Power Save disabled
                    RX Greenfield
                    RX HT20 SGI
                    RX HT40 SGI
                    TX STBC
                    RX STBC 1-stream
                    Max AMSDU length: 3839 bytes
                    No DSSS/CCK HT40
            Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
            Minimum RX AMPDU time spacing: No restriction (0x00)
            HT TX/RX MCS rate indexes supported: 0-31
            Frequencies:
                    * 2412 MHz [1] (6.0 dBm)
                    * 2417 MHz [2] (6.0 dBm)
                    * 2422 MHz [3] (6.0 dBm)
                    * 2427 MHz [4] (6.0 dBm)
                    * 2432 MHz [5] (6.0 dBm)
                    * 2437 MHz [6] (6.0 dBm)
                    * 2442 MHz [7] (6.0 dBm)
                    * 2447 MHz [8] (6.0 dBm)
                    * 2452 MHz [9] (6.0 dBm)
                    * 2457 MHz [10] (6.0 dBm)
                    * 2462 MHz [11] (6.0 dBm)
                    * 2467 MHz [12] (disabled)
                    * 2472 MHz [13] (disabled)
                    * 2484 MHz [14] (disabled)

Is there a work around for this? My 5Ghz only reaches about 15ft

2

Your wireless calibration data might have been relocated due to NAND bad blocks. See the topic below for a similar issue on another router the R6800 shares a platform with:

3

Thank you ill give this a try when I get home

4

Hello Borromini

I'm very new to this and I'm unfamiliar with compiling do you think I would be safe applying the image from this thread?

5

@Borromini So I'm trying to follow the forum that you posted and I believe I should use the following patch

diff --git a/target/linux/ramips/dts/mt7621_netgear_sercomm_chj.dtsi b/target/linux/ramips/dts/mt7621_netgear_sercomm_chj.dtsi
index 7a15cd1f6c..9def423387 100644
--- a/target/linux/ramips/dts/mt7621_netgear_sercomm_chj.dtsi
+++ b/target/linux/ramips/dts/mt7621_netgear_sercomm_chj.dtsi
@@ -81,7 +81,7 @@
        wifi@0,0 {
                compatible = "mediatek,mt76";
                reg = <0x0 0 0 0 0>;
-               mediatek,mtd-eeprom = <&factory 0x8000>;
+               mediatek,mtd-eeprom = <&factory 0x48000>;
                ieee80211-freq-limit = <5000000 6000000>;
        };
 };
@@ -90,7 +90,7 @@
        wifi@0,0 {
                compatible = "mediatek,mt76";
                reg = <0x0 0 0 0 0>;
-               mediatek,mtd-eeprom = <&factory 0x0>;
+               mediatek,mtd-eeprom = <&factory 0x4000>;
                ieee80211-freq-limit = <2400000 2500000>;
        };
 };

Here is where i believe my wifi is in my hex dump

*
00040000  15 76 a0 00 14 59 c0 c1  83 b0 15 76 c3 14 00 80  |.v...Y.....v....|
00040010  02 00 c3 14 15 76 03 22  ff ff 23 04 0d 02 8f 02  |.....v."..#.....|
*
00048000  15 76 a0 00 14 59 c0 c1  83 b1 15 76 c3 14 00 80  |.v...Y.....v....|
00048010  02 00 c3 14 15 76 03 22  ff ff 23 04 0d 02 8f 02  |.....v."..#.....|
00048020  00 80 0a 20 00 00 00 00  00 00 00 00 00 00 00 00  |... ............|
00048030  20 00 00 00 44 00 02 00  01 01 00 00 04 00 1e 00  | ...D...........|
00048040  00 00 44 00 04 00 00 00  00 00 00 20 00 20 e0 01  |..D........ . ..|

Im trying to apply the patch to the image but how do I go about compiling? Im trying the image builder by the ssh session doesn't understand the git command

6

You need this, your second edit is missing a zero:

diff --git a/target/linux/ramips/dts/mt7621_netgear_sercomm_chj.dtsi b/target/linux/ramips/dts/mt7621_netgear_sercomm_chj.dtsi
index 7a15cd1f6c..7f6fdfbafa 100644
--- a/target/linux/ramips/dts/mt7621_netgear_sercomm_chj.dtsi
+++ b/target/linux/ramips/dts/mt7621_netgear_sercomm_chj.dtsi
@@ -81,7 +81,7 @@
        wifi@0,0 {
                compatible = "mediatek,mt76";
                reg = <0x0 0 0 0 0>;
-               mediatek,mtd-eeprom = <&factory 0x8000>;
+               mediatek,mtd-eeprom = <&factory 0x48000>;
                ieee80211-freq-limit = <5000000 6000000>;
        };
 };
@@ -90,7 +90,7 @@
        wifi@0,0 {
                compatible = "mediatek,mt76";
                reg = <0x0 0 0 0 0>;
-               mediatek,mtd-eeprom = <&factory 0x0>;
+               mediatek,mtd-eeprom = <&factory 0x40000>;
                ieee80211-freq-limit = <2400000 2500000>;
        };
 };

You need to build a new image to use the modified DTS, with the image builder. Follow the instructions on the wiki, apply the patch to the source code, then build an image for your device (be sure to select the openwrt-21.02 branch and not master, so you get the web interface).

7

I just bought a R7200, Wich is quite similar to R6800. I have the same issue, but from my understanding, it's a NAND issue.

So does that mean I'll have to patch every Openwrt build I want to install to be able to have a stronger signal than 6Dbm ? Is it definitive ? In this case I should have better to send back this defective device ?