Service manual

Early scanners were crystal-controlled. These scanners had one or more internal slots for a crystal which allowed the radio to receive a single

frequency. Crystal-controlled scanners are not currently being sold. However, a number of them turn up in pawn shops and garage sales. For

example, the

PRO-25 (Cat. No. 200-0106), PRO-27 (Cat. No. 200-0108), and PRO-53 (Cat. No. 200-0122) scanners were of this type. Generally,

if you are looking at a RadioShack scanner and it does not have a keypad or program button, it is probably crystal-controlled. The disadvantage

of crystal-controlled scanners is that they were slow to tune, expensive to set-up for new frequency/channel activity, and they can not follow the

new trunked radio activity.

In the mid-80's, programmable scanners were introduced. These use integrated circuits to allow the radio to tune to a range of frequencies and

were a marked improvement over crystal-controlled scanners, which required the purchase and installation of different crystals. Programmable

scanners come with a wide range of features and capabilities and are distinguished from one another by the following features:

● The number of channels

● The frequency ranges they can pick up

● Frequency band and/or service band search

● Scan speed (channels per second and/or steps per second)

● Whether they are conventional or trunking

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Conventional Programmable Scanners:

RadioShack Scanners Features

PRO-79 Handheld Scanner

(Cat. No. 20-314)

Memory Channels: 200

Computer Interface: Scanner PC Programming Kit (Cat. No. 20-048)

Conversion System:

Dual Conversion

Size: 5 11/16" x 2 3/8" x 1 3/8"

Weather Alert: Yes

Frequency Range:

29-54 MHz, 108-174 MHz, 380-512 MHz

User's Manual Available On-line

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PRO-89 Handheld Racing Scanner

(Cat. No. 20-514)

Memory Channels: 200

Computer Interface:

Scanner PC Programming Kit (Cat. No. 20-048)

or Over-the-Air Programming

Conversion System:

Triple Conversion

Size: 5 7/8" x 2 1/2" x 1 3/8"

Weather Alert: Yes

Race Car Number On Display

Frequency Range:

29-54 MHz, 108-174 MHz, 380-512, 806-960 MHz (less cellular)

User's Manual Available On-line

Tutorials Available On-line

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