I have the bladeRF x40 board and I have issues setting TX Gains using osmocom sink in gnuradio-companion. I have a rtl-sdr as a "signal analyzer" to monitor the output (and some 20db attenuators just in case).
In the sink block there are the RF / IF / BB Gains that supposed to be matched to (according to GrOsmoSDR wiki):
Setting "sink -> RF Gain" does nothing - no change of the output (no matter what value I input)Sink:
BB Gain: TX VGA1 [-35, -4]
IF Gain: N/A
RF Gain: TX VGA2 [0, 25]
Setting "sink -> IF Gain" does nothing - no change of the output
Setting "sink -> BB Gain" works from value of 16 to roughly 72 (I can see aplitude change of the signal)
Setting BB gain below 16 throws [INFO @ fpga_common/src/lms.c:1015] Clamping TXVGA2 gain to 0dB
I was trying to see into the libbladerf and lms code looking for the gain values and it seems to correlate to above values. The bladeRF-cli works OK, so it is something on the grc->osmocom->libbladerf conenction I guess, but I am quite new to the GRC internals and couldnt find the reason for that.