Multichannel Transcranial Magnetic Stimulation is an emerging technology for non-invasive stimulation of the human brain. Combining this technique with fMRI offers the unique benefits of studying the causal relationships between the cortical and subcortical nodes of large-scale brain networks. For this reason a whole head 28-channel RF coil array was developed to be integrated with the first 3-axis-TMS multichannel system. We have analyzed how the SNR of the constructed array changes when placing the stimulation units. Additionally, we compared the SNR/g-factor maps with commercial available 32/20-channel RF coils. The results show that the RF coil is performing as expected.