MIMO channel sounding is essential for evaluating the MIMO transmission performance in real propagation environments. In this paper, we have developed a versatile channel sounder by using the GNU Radio and Universal Software Radio Peripheral (USRP) platform and the virtual antenna array method. The developed channel sounder is low cost and can be utilized flexibly for measurements in the UHF band. The performance of the developed channel sounder was validated through a T-junction cable connected test and an indoor channel measurement. The result showed that the performance quite agreed with the measurement of a VNA-based measurement system. The developed channel sounder is expected to be utilized for various kinds of propagation channel measurements.