Instead of opting for a $747 Board Mounted GPSDO (TCXO) (Recommended for USRP B200/B210)https://www.ettus.com/all-products/GPSDO-TCXO-MODULE/
Would it be possible just to change the original TCXO?
According to the "Key Component Datasheets"https://kb.ettus.com/B200/B210/B200mini/B205mini#Key_Component_Datasheets
The TCXO is identified as:
VCTCXO (B200mini only)
CTS Electronic Components Model 520 Temperature Controlled Crystal OscillatorFrequency Stability options05 = ±0.5 ppm10 = ±1.0 ppm15 = ±1.5 ppm20 = ±2.0 ppm25 = ±2.5 ppm (std)
Would a ±0.5 ppm from CTS work on the B200mini?