Trunk Tracking, Types of Trunking Systems

Radio Shack PRO-90 owner manual Trunk Tracking, Types of Trunking Systems

20-520.fm Page 32 Wednesday, August 4, 1999 3:06 PM

TRUNK TRACKING

Your scanner is designed to track transmissions on Mo- torola Type I, Type II, and hybrid analog trunking sys- tems, which are extensively used in 800 MHz communications. Remember these important points when tracking transmissions:

•Your scanner monitors Type II systems by default. However, you can change this if the system in your area is different (see “Types of Trunking Systems” below and “Scanning Type I and Hybrid Trunked Systems” on Page 44 for more information).

•Your scanner cannot track transmissions on non- Motorola trunking systems.

•Your scanner cannot track an 800 MHz trunked sys- tem and scan frequencies in conventional mode at the same time.

•The frequencies for many of the 800 MHz public safety systems are listed in the separate “National Public Safety Trunked System Frequency Guide” included with your PRO-90.

TYPES OF TRUNKING SYSTEMS

Your trunk tracking scanner can monitor two basic types of systems — Type I and Type II. Instead of selecting a specific frequency to transmit on, a trunked system chooses one of several frequencies in a 2-way radio us- er’s talk group when that user presses PTT (push to talk). Thus, trunking systems allocate a few frequencies among many different users, but the way Type I and Type II systems do this is slightly different. One important distinction between these systems is the amount of data transmitted by each radio when its push-to-talk button (PTT) is pressed. In a Type I system, the radio’s ID and its current affiliation (the trunk system it belongs to) are both transmitted. In a Type II system, only the radio’s ID is transmitted.

Why the difference? In Type I systems, each radio in the trunk group individually transmits its own affiliation, while the trunk system maintains a database that determines each radio's affiliation(s) in Type II systems.

Another difference between the systems is that Type I systems are arranged in a fleet-subfleet hierarchy. For example, it is possible for a city using a Type I system to designate 4 fleets, each with 8 subfleets.

PRO-90 specifications

The Radio Shack PRO-90 is a compact yet powerful handheld scanner that has garnered attention from both hobbyists and serious enthusiasts of radio communications. Introduced as a versatile scanner, the PRO-90 is designed for ease of use while providing a myriad of features that enhance the scanning experience.

One of the key characteristics of the PRO-90 is its advanced scanning technology. The unit boasts a 100-channel memory, allowing users to store and quickly access frequently used frequencies. The scanner supports a wide range of frequency bands, making it suitable for monitoring everything from police and fire frequencies to aviation and marine channels. With programmable scanning capabilities, users can effortlessly create their own scanning routines tailored to their interests.

The PRO-90 also features a fast scanning rate, with the ability to scan across frequencies at remarkable speeds. This minimizes the wait time for users who want to listen to different bands or channels, ensuring they never miss critical transmissions. Additionally, the scanner includes a dedicated "Hold" function that allows users to temporarily pause on a specific frequency for extended listening.

In terms of ease of use, the PRO-90 is designed with an intuitive interface. The scanner includes a backlit LCD display, making it easy to read in low-light environments. The keypad is arranged logically, enabling quick access to functions such as volume, squelch, and memory management. Users can also program the scanner via PC, thanks to its compatibility with programming software, making it easier to manage and transfer frequency lists.

Another standout feature of the PRO-90 is its ability to decode various digital signals. This includes some types of Motorola, GE, and other digital technologies, which are commonly used in modern communications. This capability extends its usefulness beyond traditional analog signals, making the scanner relevant in today’s digital landscape.

Moreover, the Radio Shack PRO-90 is designed with portability in mind. Its compact size and lightweight construction make it an ideal companion for outdoor activities, road trips, or simply enjoying the local communications landscape. Whether you’re a seasoned radio enthusiast or a newcomer to the field, the PRO-90 provides a rich set of features, advanced technology, and user-oriented design that enhance the scanning experience. It stands out as a worthy tool for anyone looking to immerse themselves in the world of radio communication.