How to receive signal from two channal of one bladeRF with the same gain

[Daisy]

Hello, everyone!

When I try to use one bladeRF to receive two channel signal, I found even I set the same gain for the two channel by "set gain rx1 10" and "set gain rx2 10", the receiving gain is still not the same. The gain on RX2 is always much lower than RX1.

My code is
set frequency rx1 433M
set frequency rx2 433M

set samplerate 1MHz
set bandwidth 500kHz

set agc off
set gain rx1 10
set gain rx2 10

rx config file=testsc16q11 format=bin n=10M channel=1,2 timeout=60s


I don't know what the reason is. Has anyone encountered a similar situation?

Thank you very much for your help

[ve7til]

I also have the exact same issue.

For example I run this script.

rx config file=dual_test.bin n=10M channel=1,2
set frequency rx 2211.5e6
set samplerate 2e6
set agc 0
set clock_ref 1
rx start

Here's a print:
p

RX1 Bandwidth: 18000000 Hz (Range: [200000, 56000000])
RX2 Bandwidth: 18000000 Hz (Range: [200000, 56000000])
TX1 Bandwidth: 18000000 Hz (Range: [200000, 56000000])
TX2 Bandwidth: 18000000 Hz (Range: [200000, 56000000])

RX1 Frequency: 2211500000 Hz (Range: [70000000, 6000000000])
RX2 Frequency: 2211500000 Hz (Range: [70000000, 6000000000])
TX1 Frequency: 2400000000 Hz (Range: [47000000, 6000000000])
TX2 Frequency: 2400000000 Hz (Range: [47000000, 6000000000])

Tuning Mode: Host

Bit Mode: 16 bit samples

Feature: Default enabled

RX1 AGC: Disabled
RX2 AGC: Disabled

Clock reference: REFIN to ADF4002 (locked)
REFIN frequency: 10000000 Hz
Clock input: Onboard VCTCXO
Clock output: Disabled

RX1 RSSI: preamble = -96 dB, symbol = -114 dB
RX2 RSSI: preamble = -96 dB, symbol = -110 dB

Loopback mode: none

RX mux: BASEBAND - Baseband samples

RX FIR Filter: 4x decimation
TX FIR Filter: 4x interpolation

Gain RX1 overall: 60 dB (Range: [-15, 60])
full: 71 dB (Range: [-4, 71])
Gain RX2 overall: 60 dB (Range: [-15, 60])
full: 71 dB (Range: [-4, 71])
Gain TX1 overall: 56 dB (Range: [-23.75, 66])
dsa: -90 dB (Range: [-89.75, 0])
Gain TX2 overall: 56 dB (Range: [-23.75, 66])
dsa: -90 dB (Range: [-89.75, 0])

RX1 sample rate: 2000000 0/1 (Range: [520834, 122880000])
RX2 sample rate: 2000000 0/1 (Range: [520834, 122880000])
TX1 sample rate: 2000000 0/1 (Range: [520834, 122880000])
TX2 sample rate: 2000000 0/1 (Range: [520834, 122880000])

Bias Tee (RX1): off
Bias Tee (RX2): off
Bias Tee (TX1): off
Bias Tee (TX2): off

Current VCTCXO trim: 0xc000
Stored VCTCXO trim: 0x1ecf

Hardware status:
RFIC status:
Tuning Mode: Host
Temperature: 31.6 degrees C
CTRL_OUT: 0xf8 (0x035=0x00, 0x036=0xff)
Power source: USB Bus
Power monitor: 4.84 V, 0.57 A, 2.76 W
RF routing:
RX1: RFIC 0x0 (A_BAL ) <= SW 0x0 (OPEN )
RX2: RFIC 0x0 (A_BAL ) <= SW 0x0 (OPEN )
TX1: RFIC 0x0 (TXA ) => SW 0x0 (OPEN )
TX2: RFIC 0x0 (TXA ) => SW 0x0 (OPEN )


RX2 is always at a much lower gain no matter what I set it to. See:
]https://www.dropbox.com/scl/fi/uu8sk1m ... 2s7ru&dl=0

I've also tried gr-bladerf and the osmocom in gnuradio and same result.

Essentially it destroys the MIMO functionality of the BladeRF2. Any work around?

Thanks