The RF board used in APX8000 APX8000XE is only tested during installation and has not been used. There are multiple boards that will be sent out after being tested and qualified using AEROFLEX3920 after installation. If you do not have a comprehensive test to perform calibration after replacement, you can provide your machine serial number. We can provide you with an automatic calibration adjustment file with the same serial number and save it to you. After replacing the RF board, use APX TUNER to write it in. Each launch plate will correspond to a different calibration storage file. This will ensure that you maintain the optimal working condition after replacing the launch pad, and this service is not charged separately. When you find that the machine you are using has poor reception; Various RF faults such as insufficient power can mostly be repaired by replacing the RF board. If there are other equipment issues, please consult and communicate. Sold RF boards do not accept returns or exchanges.