ut level The IPA and its power supply shall have redundancy incorpor- ated in the design. The IPA shall be provided with an output ferrite circulator for protection against excessive VSWR or an inadvertent disconnection from the IOT amplifier. Exciter System Each exciter shall include all necessary switching, control, and status monitoring. The 19.39 Mb/s transport stream input to the exciter will comply with SMPTE 310M or DVB-ASI standard. The exciters shall convert the 19.39 Mb/s transport stream to an 8VSB-modulated car- rier. Exciters shall perform frame data randomization, Reed-Solomon encoding, data interleaving, Trellis coding, segment and field sync insertion, pilot insertion and filtering, and be fully compliant with ATSC A/53 Standard and applicable FCC Regulations. The exciters shall include automatic signal processing for the pre- correction of the signal to compensate for linear and non-linear errors in the transmitter amplifier stages and to provide group delay cor- rection for group delay errors introduced in the output RF system, as well as an RF combiner when present. RF Output System The RF system shall be of coaxial and/or waveguide construction, and RF inputs and outputs shall be standard EIA coaxial flanges. A low loss, constant impedance-type band-pass filter shall be sup- plied with each transmitter to meet the FCC Mask requirements. The filter shall be supplied with reject and ballast loads. 7 SPECIFYING EQUIPMENT AND SERVICES The RF system shall be supplied with a motorized antenna/load RF switch, liquid cooled test load, and calorimeter power measuring equipment. The switch shall be provided with integral interlocks as a part of the transmitter control system to permit easy connection of the transmitter to the test load. Two precision calibrated directional couplers shall be provided on the output of the RF system ahead of the antenna/load switch for station use. One indicates forward power, the other reflected power. High Voltage Supply The high voltage supply shall be oil filled and se