OPTIMOD-AM is a powerful system for obtaining the best possible quality from the AM broadcast medium. This medium includes the station's transmission system plus the listener's receiver, listening environment, and , The OPTIMOD-AM 9100A system is designed for universal application in domestic ; and international LW, MW, and SW services. While OPTIMOD-AM is ordinarily shipped with a 12kHz output bandwidth to comply with FCC (U.S.A.) specifications for the U.S. MW broadcast service, an optional 5kHz bandwidth-limiting filter card may be plugged into the system to conform its output spectrum to EBU and other ! standards, or to resolve unusual adjacent channel interference problems. 1 OPTIMOD-AM is available in two versions: a stereo version (9100A/2) which | processes by the "sum-and-difference" method to yield ready compatibility with any proposed AM Stereo system, and a mono version (910GA/1) which can be field-converted to stereo by plugging in three additional circuit cards. No "Stereo I Accessory Chassis" is required. By performing the following functions, the OPTIMOD-AM system delivers a louder, i cleaner, brighter, FM-Iike sound whose open, fatigue-free quality attracts listeners I and holds them: 1. It rides gain over a range of as much as 25d8, compressing dynamic range and compensating for gain-riding errors on the part of operators and for gain inconsistencies amongst automation tapes. The amount of dynamic range reduction is adjustable. 2. It increases the density and loudness of the program material by means of multiband limiting and multiband distortion-cancelled clipping, achieving remarkable increases in loudness and definition without audible side-effects. 3. It compensates for the high- and low-frequency rolloffs of typical AM receivers by means of a statistically-derived fully-adjustable program equalizer. Up to 22dB of HF boost can be produced above 6kHz. This extreme equalization can be readily handled by the processing without the side-effects encountered in conventional processors. 4. It reliably controls peak levels to prevent overmodulation. 5. It improves the consistency of the station's equalization texture by means of multiband limiting. 6. It compensates for inaccuracies in the pulse response of transmitters and antenna systems by means of a powerful transmitter equalizer with four adjustable correction parameters. Four complete sets of adjustments may be preset and recalled as needed by remote control. 7. It controls the bandwidth of the transmitter emissions as necessary to meet the specifications of government authorities, regardless of program material or equalization settings.