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Scanner decision


One of the most often asked questions on the Radio Reference forums is actually a set of questions dealing with what scanner should someone buy. They often take the form of, "What is the best scanner for where I live?" or "What is the cheapest digital scanner I can buy?".

Hopefully this article will address these concerns and answer some of the questions the potential scanner user (and some new scanner users) have about what they must have to get into this hobby. This article will restrict itself to answering the basic questions that need to be addressed and will not deal with additional accessories that you may have heard of or are contemplating such as outside or mobile antennas, external speakers, computer programming of the specific scanners, etc.


Contents

Overview

  • What is a scanner?
    • It is a frequency agile radio that will allow you to program in various radio frequencies and then it will scan those frequencies looking for activity allowing you to listen to that activity.
  • What sort of stuff can I hear?
    • Scanners are typically used for monitoring Public Safety communications such as Fire, Police, Medical services, etc. They can be used for monitoring business activities, Family Radio Service (FRS), Citizens Band (CB), etc.
  • Are all scanners alike?
    • All scanners share some common characteristics, they are all radios and they are designed to scan a set of frequencies; however, each scanner model is different from other scanner models. In addition some hobbyist radios are not really scanners but they may scan; for example an amateur radio transceiver may be able to scan, but that is not its prime function.

Definitions

To help you make your decision as to what type or model of scanner you need, we have to define some common terms used in the scanning community. You must keep these in mind when deciding on your needs and considering your purchase.

Configuration

Scanners come in two basic configurations:

Hand Held

These are portable scanners, designed to be carried around by hand, clipped to your belt, or in some cases slipped into your pocket. These are battery powered and are of course therefore limited in the amount of time they may be used before the battery power is diminished. Several hand held scanners do use rechargeable batteries and usually include a recharging circuit in the radio to recharge the batteries. Most experienced scanner users carry extra batteries with them and also do not recharge the batteries in the radio but use some sort of external battery charger.

Mobile/Base

These are scanners designed to operate from vehicle power (usually a nominal 12 volts DC) or in the case of Base Only scanners, from house power. Most of these base class of scanners are really mobile scanners that use a 12 volt "wall wart" power supply to supply the needed power. In most cases there is usually a hand held model that is the sister to the mobile/base model; typically in this case the radios are exactly the same, the only difference being the case and the size of the speaker inside the radio.

Types

Scanners are roughly divided into two types:

Conventional

A conventional scanner is designed to follow sets of discrete frequencies, each one carrying separate types of conversations. Conventional scanners are not capable of properly following trunked conversations (see next topic.)

Trunk Tracking

A trunk-tracking scanner is designed to allow the programming of a set of frequencies that are used among several channels or agencies on a shared basis. See the Trunking Basics article for an overview of how trunking works. All trunk tracking scanners are also conventional scanners.

The most common trunking system types are:

  • Motorola
  • EDACS
  • LTR
  • Project 25

Scanners are available to work with all of these types of systems, but not all scanners can receive all types.

  • Note: Receivers - Receivers are not normally considered scanners, they may be able to scan, indeed some are very good at it; however, receivers are typically used to cover sections of the RF (Radio Frequency) Spectrum in finer detail. Most are designed to cover a greater amount of spectrum than the typical scanner. They are typically used for Utility Monitoring and/or Short Wave Listening (SWL) in the high frequency (HF) band. No receivers are trunk-tracking capable, and most receivers can receive only analog signals (AM, FM, SSB), not digital ones (AMBE, IMBE, etc).

Frequency Coverage

Not all scanners cover the same frequencies. Most scanners currently on the market cover the most commonly used public safety and business bands. It is important to determine what bands or range of frequencies interests you so you can make sure the scanner you buy is equipped to receive those bands. A common mistake made by the new scanner purchaser is to have an interest in, for example, military air communications (MilAir), and discover only after purchase that their chosen scanner does not cover that band -- or receives it poorly.

Modes

All typical scanners have the common modulation methods (such as FM and AM) used in public safety or aircraft, but there are many newer modes, and not all scanners can receive them.

Analog

This is the most common type of transmission method currently in use; however, it is giving way to the digital modulation age. All scanners are capable monitoring analog transmissions. In regards to public safety monitoring, this typically means FM type of transmissions. In aircraft monitoring, this is normally AM transmissions. Some scanners, and many receivers, can also receive the Wide-FM signals of FM broadcast stations.

Digital

This is where it becomes a little more involved. Over the years various methods of digitally encoding voice to send across the airwaves have been developed. In public safety use today there are two main ones you need to be concerned with, one is P25 CAI and the other is ProVoice.

The important thing to remember is that there are no scanners capable of decoding ProVoice. Scanners are made to decode P25 digital modulation, but that capability comes at a premium price. There are other digital modes that you may run across during your research, for example: VSELP (not monitorable) or OpenSky (not monitorable). The thing to remember is today the only digital mode used that is monitorable by today's scanners is APCO-25 (P25 CAI). (Don't confuse the P25 Common Air Interface, which is just the audio encoding method, with Project 25 which is the entire trunking system, with a 9600bps control channel.)

Memory Management

New scanners have two basic memory management schemes:

Banks & Lists

The banks and lists scanner is the most common scanner on the market. It consists of a fixed number of banks with a fixed number of slots in each bank into which frequencies may be programmed.

Dynamic Memory

The dynamic memory scanner is the wave of the future in scanners. Introduced in scanners by Uniden with the SC230 scanner in 2004, it is quickly becoming the prime method of managing memory in today's scanners. In this system the number of slots for frequencies and trunking talkgroups is flexible. This enables programming small systems into their own bank and not wasting the remaining empty slots in that bank, as fixed memory scanners do. Instead those slots may be used in another bank for a larger system, one that may be too large for a bank on a fixed memory scanner. Some of these scanners allow a frequency/talkgroup to be used in one or a multiple number of banks, avoiding the need for memory wasting duplications. Dynamic memory capability has been offered in commercial grade transcievers since the late 1980's or early 1990's. GRE has a related system that's referred to as 'Object Oriented'.

Information Needed

The first task that you should perform is to determine what there is in your area that you are interested in monitoring.

Sources

RR Database

Fortunately you have access to the most comprehensive database of such information, right at this site. The Radio Reference Database provides the information you need to make a decision what your scanning needs are. When looking at the RR Database please remember to look to see if you need to have trunking support and/or digital needs. If looking at a Trunking System, please make note of the System Type and the System Voice lines at the top of the page, they provide the information as to what type of trunking scanner you need.

Other Web pages

There are several well-known websites (such as the CARMA website for the Chicago area) that list frequencies and other information. If you don't find what you are looking for in the database, check the United States and Canada articles for these. There are also numerous mailing lists (many are on Yahoo groups) that cover specific states and/or regions. These are also linked on the above articles.

FCC Database

You can search via the FCC's data base for your area if you are in the United States or one of its territories. The FCC database does not tell you what type of trunking system might be in use. It is possible to do a geographical search at the FCC site.

Others

There are other methods of finding out what is local to you including Internet searches and indeed you can buy the information; however, the above two are free and will provide you with a fairly comprehensive list of what is used in your area and certainly enough information so that you can decide what your scanner needs are.

What's Available

Using the information you have gathered thus far, take a look at the various scanners shown here on the RR Wiki by looking at the Radio Models linked from the main page. You should concentrate your efforts on GRE, Radio Shack (most of whose scanners are OEMd by GRE), and Uniden; the others listed are typically not scanners as defined here.

Budget

This is where you must make a decision on how much you want to commit to this hobby. This will generally be more than your wife would prefer.  :-)

New

A good analog-only trunk tracking scanner can be had for less than $200; however, if you need to be able to monitor APCO P25 Systems, you are looking at the $500 range.

Used

The used market provides (with some judicious shopping) an attractive alternative to the new hobbyist. The caution here is to ensure that you understand the product you are buying will meet your scanning needs, and of course the watchword whenever dealing in used products is "buyer beware."

Decision Time

Now is the time to apply the information gathered above to what your individual needs are. Obviously each person reading this article will have different needs, wants, and budget. Only you can provide the answer as to what the "best scanner" is for you. However, armed with the information above, use the RR Regional Forums to ask your neighbors what they are using and/or recommend.

Welcome to the hobby!



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