Hi all.
I know this topic was covered before but my case is somehow different. I acquired already modified LimeSdr USB for better HF performance. Modification was done by third party vendor.
Loopback test is as follows:
[ RF Loopback Test ]
->Configure LMS
->Run Tests (TX_2-> LNA_L):
CH0 (SXR=800.0MHz, SXT=805.0MHz): Result:(-13.4 dBFS, 5.00 MHz) - PASSED
CH1 (SXR=800.0MHz, SXT=805.0MHz): Result:(-15.4 dBFS, 5.00 MHz) - PASSED
->Run Tests (TX_1 → LNA_W):
CH0 (SXR=1800.0MHz, SXT=1805.0MHz): Result:(-13.4 dBFS, 5.00 MHz) - PASSED
CH1 (SXR=1800.0MHz, SXT=1805.0MHz): Result:(-16.8 dBFS, 5.00 MHz) - PASSED
->Run Tests (TX_2-> LNA_H):
CH0 (SXR=2500.0MHz, SXT=2505.0MHz): Result:(-50.9 dBFS, -0.01 MHz) - FAILED
CH1 (SXR=2500.0MHz, SXT=2505.0MHz): Result:(-14.7 dBFS, 13.63 MHz) - PASSED
->RF Loopback Test FAILED
=> Board tests FAILED <=
My concern is:
->Run Tests (TX_2-> LNA_H):
CH0 (SXR=2500.0MHz, SXT=2505.0MHz): Result:(-50.9 dBFS, -0.01 MHz) - FAILED
I noticed following elements removed from board:
MN22, MN18, MN26 and MN50
Checking LimeSDR_HF_Performance article I don’t find all of above mentioned elements should be removed from board (please correct me if I’m wrong).