20-521.fm Page 52 Wednesday, August 4, 1999 3:32 PM

When a Type I system is designed, the address infor- mation for all its user IDs is divided into 8 equal-size blocks, numbered 0–7, and each block is assigned a size code. When you set up your scanner to track a Type I system, you must choose a size code for each block. When you have chosen a size code for all 8 blocks, you will have duplicated the fleet map for the system you are tracking. If you have chosen correctly, you will be able to track transmissions in that system.

Each size code defines the number of fleets, subfleets, and IDs each block has. For example, you can see in the following table that a size code of S-4 has one fleet, which is divided into 16 separate subfleets, and it has a total of 512 individual IDs.

Size

Fleets

Subfleets

IDs

Blocks

 

 

 

 

Used

 

 

 

 

 

 

 

 

S-0

Reserved block for Type II IDs

 

 

 

 

 

 

S-1

128

4

16

1

 

 

 

 

 

S-2

16

8

64

1

 

 

 

 

 

S-3

8

8

128

1

 

 

 

 

 

S-4

1

16

512

1

 

 

 

 

 

S-5

64

4

32

1

 

 

 

 

 

S-6

32

8

32

1

 

 

 

 

 

S-7

32

4

64

1

 

 

 

 

 

S-8

16

4

128

1

 

 

 

 

 

S-9

8

4

256

1

 

 

 

 

 

S-10

4

8

256

1

 

 

 

 

 

S-11

2

16

256

1

 

 

 

 

 

S-12

1

16

1024

2

 

 

 

 

 

S-13

1

16

2048

4

 

 

 

 

 

S-14

1

16

4096

8

 

 

 

 

 

Each ID in the block is unique. The left-most digit is the block number in the ID. The next two digits identify which fleet is active, and the last digit(s) (after the hy- phen) identifies the subfleet.

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Image 52
Radio Shack PRO-91 owner manual Size Fleets Subfleets IDs Blocks Used
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PRO-91 specifications

The Radio Shack PRO-91 is a handheld scanner that appeals to both amateur radio enthusiasts and professionals seeking a reliable and versatile communication device. Known for its user-friendly design and wide range of features, the PRO-91 is an excellent choice for monitoring various frequencies, including VHF and UHF bands.

One of the standout features of the PRO-91 is its capability to scan frequencies in the 25-1300 MHz range, which allows users to listen in on a variety of communications. This includes police, fire, and emergency services, as well as amateur radio transmissions and aircraft communications. The scanner supports both analog and some digital formats, making it adaptable to different communication standards and ensuring users stay updated with relevant broadcasts.

The PRO-91 comes with 200 programmable channels, allowing users to store their favorite frequencies for quick access. It also features a million frequency search capability, enabling it to detect active signals within the scanning range. Additionally, the scanner includes a priority channel function, permitting users to designate a specific frequency to continuously monitor while scanning through other channels.

Another notable characteristic of the PRO-91 is its triple conversion design, which enhances sensitivity and selectivity, resulting in improved audio clarity and reduced interference. The unit is equipped with a robust speaker that delivers clear sound quality, making it easy to understand transmissions even in noisy environments.

Users will appreciate the ergonomic design of the PRO-91, which features intuitive controls and a backlit LCD display for easy visibility, even in low-light conditions. The keypad layout is designed for straightforward operation, allowing even novice users to navigate through menus and settings with ease.

The PRO-91 is powered by a rechargeable battery, offering extended usage without the need for constant battery replacements. Its compact and lightweight construction makes it portable, making it suitable for on-the-go monitoring.

In conclusion, the Radio Shack PRO-91 offers an impressive array of features, technologies, and characteristics that cater to diverse scanning needs. With its wide frequency range, programmable channels, and superior audio quality, it stands out as a reliable choice for anyone looking to explore the world of radio communication. Whether for recreational use or professional monitoring, the PRO-91 ensures users remain connected to the signals that matter most.
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