The 8185A Stereo Generator is a high-performance BTSC-standard stereo generator having superb audio quality and exceptional stability. Although the 8185A will work with any audio processor, it is designed to be especially effective when used in conjunction with the Orban OPTIMOD-TV audio processor. The 8185A far exceeds BTSC requirements, delivers unimpeachable subjective audio quality, and uses extremely high-performance low-pass filters to achieve excellent high-frequency response and the industry’s best aliasing rejection. The 8185A Stereo Generator has a digital baseband encoder, group delay equalization, and upgraded noise reduction circuitry for better overall performance and tighter specifications. • Digital baseband encoder generates BTSC-standard stereo subchannel and composite baseband. Fig. 1-2 shows the very clean baseband spectrum produced by the Hadamard Transform Baseband Encoder™ • Separation performance exceeds all BTSC specifications. • Works with any audio processor. (Has +10dBm active-balanced left and right inputs, and can accept flat or pre-emphasized input.) • When used with the Orban 8182A OPTIMOD-TV Audio Processor, a special interface allows interleaving of circuitry to get the brightest sound with the lowest distortion. • Easy to install and operate. • Built-in Bessel null calibration tone. • Built-in peak-indicating meter for input, circuit, and output levels. • Sharp filtering protects pilot and prevents crosstalk between the main channel and subchannel (see Fig. 1-3). • Excellent protection from aliasing. • Group delay equalization of low-pass filters to minimize overshoots (see Fig. 1-4). • dbx® noise reduction encoder. • Built-in dbx noise reduction decoder, de-emphasis, and de-matrixing for monitoring audio up to the baseband encoder. • Optional 8185A/PRO Professional Channel Generator circuitry. • Input port for separate Second Audio Program channel generator. • Optically-isolated remote control inputs for switching between stereo and mono operation, for monitoring sync lock status, and for controlling the optional 8185A/PRO Professional Channel Generator.