Digital Hybrid Wireless is a new design that overcomes channel noise by involving the patent-pending process of combining digital audio with an analog FM wireless link. This proprietary method eliminates the artifacts of a typical compandor design. SmartSquelch technology in the UCR401 avoids the compromises of conventional receiver designs, adjusting squelching behavior dynamically under varying conditions to deliver acceptable audio quality from otherwise unusable signals. The algorithm waits for a complete word or syllable before squelching, assesses recent squelching history and RF signal strength, and assesses audio content to determine available masking. A DSP-generated ultrasonic pilot tone from the transmitter controls the receiver audio muting (squelch) and eliminates thumps, pops and other transients by sensing the pilot tone and incorporating brief delays when the matching transmitter is turned on or off. The pilot tone frequency is unique for each of the 256 frequencies in the tuning range (frequency block) of a system, which simplifies the coordination of multi-channel wireless systems. The use of DSP further offers increased reliability through the elimination of the fragile, shock-sensitive crystal designs of older analog pilot tone systems.
Proprietary SmartNR noise reduction increases the effective dynamic range of the system by removing hiss without sacrificing the coherence of high-frequency transients and speech tones. SmartNR offers significantly increased transparency over the sophisticated variable low pass filters used in previous designs by attenuating only those portions of the audio signal that fit a statistical profile for randomness or "electronic hiss." Microprocessor-controlled antenna phase combining keeps the UCR401 receiver small yet still able to deal effectively with multi-path dropouts. Lectrosonics' adaptive SmartDiversity(tm) analyzes the incoming RF level and the RF level's rate of change to determine the optimum timing for phase switching and the optimum antenna phase and anticipate dropouts before they occur.
The system also employs "opportunistic switching" to analyze and then latch the phase in the best position during brief squelch activity. Like the UCR211 and 411A before it, the UCR401 incorporates a menu-driven graphic LCD. This provides a convenient means of viewing and altering user settings and allows the user to view a graphic scan of the local-area RF conditions for ease of finding a clean operating frequency. Balanced audio output is via an industry standard XLR connector. The UCR401 may be operated using two internal AA batteries or external DC power.