The Hark PPM-8 Base Station RF Power Monitor is an intelligent transmitter power failure-sensing unit for use with two-way and trunked radio systems. By monitoring the transmit channel activity and power, a weak or failed transmitter can be detected. This failure is automatically signaled to the base station controller in order to remove the channel from use by the system.

Each PPM-8 will sample up to 8 channels and uses power sensors to detect low power, no power and SWR levels to the microprocessor-based unit. The PPM-8 has an automatic learn function to set the existing power output as normal. The PPM-8 then computes the failure margin selected and sets this value as the limit for failure. The PPM-8 is compatible with both high power and low power transmitter models