Digital Operation. Radio Shack PRO-96, PRO-2096

Digital Operation

Your scanner is equipped with advanced Digital Signal Processing circuitry to receive and decode Phase 1 APCO-25 C4FM (four level FM) digital voice transmissions. This section of the manual will help you understand the differences between traditional analog and digital modulation.

For ease of use, your scanner is designed to automatically detect digital modulation on any conventional channel programmed for FM/Digital (FM) modulation. It is not necessary to configure individual channels for digital operation.

Many digital trunked radio systems are actually mixed mode systems that support both analog and digital modulation. Certain user groups on these systems may use analog modulation, while others use digital modulation. Your scanner will automatically detect the type of modulation being used and switch to the correct modulation mode without special programming or user intervention.

Your scanner also features Intelligent Adaptive Digital Tracking for optimal reception of digital signals from a variety of digital conventional and trunked radio system types. No special sound quality settings or adjustments are needed for different C4FM system types.

Digital modulation represents a breakthrough in public safety communications technology. Digital modulation typically provides a clear, distortion free audio signal throughout the service area of the system you are monitoring. However, there are some important differences between analog and digital voice performance that you should be aware of while scanning.

In most cases, digital voice transmissions will be surprisingly crisp and clear, and without noise or distortion, even when corresponding analog signals from the same system contain some static. However, if you are in a location with marginal reception, you may find that the voice quality of digital signals deteriorates very rapidly, resulting in missing syllables or entire words. If this happens, try reorienting the scanner or antenna for better reception. You may also try pressing the ATT key and apply attenuation to reduce the overload effects of nearby strong transmitters.

Under certain very weak digital signal conditions, the scanner may lose synchronization with the digital signal and briefly revert to analog FM, resulting in the reception of the raw,

88