Hello friend!
As far as I know, the MRFU is not suitable for the APM cabinet.
The maximum transmit power of an RFU varies by model. A higher transmit power of an RFU indicates higher requirements for power distribution and heat dissipation of the cabinet. Therefore, low-power RFUs are applicable to all types of cabinets. High-power RFUs are applicable only to Ver.C cabinets, Ver.D cabinets, upgraded cabinets that have the same capabilities as Ver.D cabinets, Ver.E cabinets, upgraded cabinets that have the same capabilities as Ver.E cabinets, and BTS3900AL (Ver.A) cabinets.
The following describes the cabinet types applicable to the MRFU:
BTS3900 (Ver.B), BTS3900 (Ver.C), BTS3900 (Ver.D), BTS3900 (Ver.D_A), BTS3900 (Ver.D_B), and BTS3900 (Ver.E_A~D)
BTS3900L (Ver.B), BTS3900L (Ver.C), BTS3900L (Ver.D), BTS3900L (Ver.D_B), and BTS3900L (Ver.E_B~D)
RFC (Ver.B), RFC (Ver.C), RFC (Ver.D), RFC (Ver.E), RFC (Ver.D_C), RFC (Ver.D_B), and RFC (Ver.D_A)
BTS3900AL (Ver.A)
Hope this helps!