[Discuss-gnuradio] questions about calibration examples in UHD utility

[gang li]

Hi, guys,

I am reading the codes for uhd_cal_rx_iq_balance.cpp.
When doing calibration by setting the RX and TX antenna as "CAL", is
the signal from TX directly switched to RX?
And I noticed that in the function set_optimum_defaults(), the tx_gain
is 0 but the rx_gain is 25! Is that too high? I heard that when
directly connecting TX and RX, we should use attenuators. So why does
it set 25 rx_gain? Thanks.

Best,
Gang