788 High Efficiency FM Analog/HD Digital Diplexer

ERI’s 788 High Power HD Radio FM Analog/HD Digital Diplexer is modular in construction and designed to provide close channel combining for analog and digital FM broadcasting. ERI’s innovative All Pass design allows stations to operate digitally at HD Radio power levels up to -10dBc.

This All Pass Diplexer maintains high efficiency while incurring a much smaller penalty to performance than other methods currently offered. As with all ERI products, the 788 Series use a temperature compensated design to allow the system to meet published specifications from cold start as well as normal operating conditions. All components in the RF path are copper or silver plated to maintain the lowest losses possible. The modules are designed to be or mounted and is optionally available fully assembled within a mobile frame to ease installation.

Model 788 All Pass FM Analog/IBOC diplexer. Includes cavities, 3 dB hybrids, and reject load. Convection cooled. Rated to 22 kW analog plus 3.0 kW digital power Specify operating frequency, and injection level, at time of order. Analog RF input 3-1/8-inch EIA male, digital RF input 1-5/8-inch EIA male, and RF output 3-1/8-inch EIA, male.


  • Combines High Power Analog and HD Digital FM Transmitters into one Common Output Efficiently
  • Models available to Combine up to 49 kW Analog FM Transmitters with with HD Digital Transmitters Operating at -10dBc Injection Levels
  • When Tuned and Balanced with an Antenna Load, the AllPass can Provide Greater than 40 dB Isolation between the the FM Analog and HD Digital Transmitters
  • In most instances the existing station's Analog transmitter and antenna can be used, requiring only the purchase of the AllPass Combiner and a Digital IBOC transmitter

788 High Efficiency FM Analog/HD Digital Diplexer Product Brochure

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