GSM signal B210, unwanted frequency

[kielcondi]

I am operating a GSM signal with B210 and osmocom. My carrier signals are at 942.4 MHz and 959.8 MHz. There is an unwanted frequency observed at 951.1 MHz, which is exactly in between the two carrier signal. I tried to change the combination of frequencies, but still the problem persists and it was still exactly in between the those carrier signals. I suspect it was the transceiver chip of B210 because the TXA and TXB share the same LO. Is there any way or calibration I need to do first to eliminate this unwanted frequency? Thank you. 

[altenbach]

I don't think that has anything to do with "signal conditioning" and probably belongs here. If you agree, I can move this tread.

[kielcondi]

Hi. Thank you for informing me. Kindly move this thread. Thank you so much.