Conway, Z.A. Anderson, R. Brutus, J.C. Hernandez, K. Holmes, D. Mernick, K. Narayan, G. Polizzo, S. Seberg, S.K. Severino, F. Sowinski, M. Than, R. Wu, Q. Xiao, B.P. Xu, W. Zaltsman, A. JACoW Publishing Geneva, Switzerland 2673-5504 978-3-95450-234-9 10.18429/JACoW-SRF2023-WEPWB061 English 718-720 cryomodule operation coupling cavity HOM Contribution to a conference proceedings 2023 2023-09 https://doi.org/10.18429/JACoW-SRF2023-WEPWB061 https://jacow.org/srf2023/papers/wepwb061.pdf Pre-installation test results for the RHIC 56 MHz superconducting RF system are presented here. The 56 MHz quarter-wave resonator achieved a stable accelerating potential of 1.1 MV with 13 W of RF loss at 4.5 K demonstrating its viability for increasing the luminosity of sPHENIX collisions. The new 120 kW travelling wave fundamental mode damper and dual 6 kW combined-function fundamental power couplers perform as expected at 3 kW but remain to be operated with the expected ~40 times greater power achievable with the RHIC sPHENIX beams.