I have the same question that if I should pay for the calibration reference design .there are 2 bit files,one is 089_ml605_fmc126 ,and the other is 192_ml605_fmc126_cal ?? from the log.txt ,I find the calibration need almost 1 minute, i want to know if I should calibrate it every time or just for one time ? if I change the sample frequence to 3G, should I calibrate again?