Wireless virtualization aims to support concurrent experiments on shared wireless network resources. This research is based on efforts to enhance the control structure of the wireless test bed 'ORBIT' through different forms of virtualization. The focus of this paper is virtualization in frequency or frequency division Multiplexing (FDM), and more specifically using multiple wireless interfaces per node and splitting the wireless medium by assigning a different channel frequency to each interface. A wireless node is virtualized through User Mode Linux (UML), with each sliver or experiment using a different interface. Extensive experimental results are presented that analyze the effectiveness of this method of virtualization in terms of different types of traffic. We examine cross-coupling effects of coexisting virtualized experiments and investigate proof-of-concept virtualization for one typical usage scenarios. This research provides practical guidance for the use of this type of virtualization for simultaneous wireless experiments.