[FS#557] Nexx wt3020 wifi rx sensitivity low with LEDE 17.01

[LEDE Bugs]

The following task has a new comment added:

FS#557 - Nexx wt3020 wifi rx sensitivity low with LEDE 17.01
User who did this - Rod Egan (Greybeard)

----------
Tried with LEDE Reboot SNAPSHOT r3975-97d1c49 
RX signal still poor
Also noted that with country code set to AU, TX power can supposedly be set to 36dBm!

root at LEDE:~# iw list
Wiphy phy0
        max # scan SSIDs: 4
        max scan IEs length: 2257 bytes
        max # sched scan SSIDs: 0
        max # match sets: 0
        max # scan plans: 1
        max scan plan interval: -1
        max scan plan iterations: 0
        Retry short long limit: 2
        Coverage class: 0 (up to 0m)
        Available Antennas: TX 0 RX 0
        Supported interface modes:
                 * IBSS
                 * managed
                 * AP
                 * AP/VLAN
                 * monitor
                 * mesh point
        Band 1:
                Capabilities: 0x2fe
                        HT20/HT40
                        SM Power Save disabled
                        RX Greenfield
                        RX HT20 SGI
                        RX HT40 SGI
                        TX STBC
                        RX STBC 2-streams
                        Max AMSDU length: 3839 bytes
                        No DSSS/CCK HT40
                Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
                Minimum RX AMPDU time spacing: 2 usec (0x04)
                HT TX/RX MCS rate indexes supported: 0-15, 32
                Frequencies:
                        * 2412 MHz [1] (36.0 dBm)
                        * 2417 MHz [2] (36.0 dBm)
                        * 2422 MHz [3] (36.0 dBm)
                        * 2427 MHz [4] (36.0 dBm)
                        * 2432 MHz [5] (36.0 dBm)
                        * 2437 MHz [6] (36.0 dBm)
                        * 2442 MHz [7] (36.0 dBm)
                        * 2447 MHz [8] (36.0 dBm)
                        * 2452 MHz [9] (36.0 dBm)
                        * 2457 MHz [10] (36.0 dBm)
                        * 2462 MHz [11] (36.0 dBm)
                        * 2467 MHz [12] (36.0 dBm)
                        * 2472 MHz [13] (36.0 dBm)
                        * 2484 MHz [14] (disabled)
        valid interface combinations:
                 * #{ managed, AP, mesh point }