While scanner use a different type of memory, the above comparison still illustrates that the small amount of memory in today's scanners is not a significant cost of producing the radio. Nowadays even a budget computer will contain several gigabytes of memory, a 10,000 fold increase in capacity. By comparison with personal computers, when the first 300 channel scanner hit the mainstream consumer market in 1986, a typical personal computer included less than 640k of memory. The decision on how many channels a scanner will contain is driven more by marketing and usability concerns than technical or cost limitations. What Determines How Many Channels or Objects A Scanner Contains Some people may travel to the same locations for work, to visit relatives, or even vacation. He may listen to local government operations like buses, highway maintenance, and animal control only on rare occasions, but still likes the flexibility of doing so without having to reprogram the radio.Ī listener may also program in frequencies for different geographical areas. He may listen to police and fire services in nearby jurisdictions only occasionally, such as during a high-profile emergency. A person may not listen to FEMA very often, but when a disaster does happen, it is convenient to already have those frequencies and identifying information already programmed into the radio, especially when power and internet access may be down.Ī listener may have other services he listens to only occasionally. Certain frequencies are used by responders during search and rescue operations, or in major natural disasters like hurricanes, tornados, and earthquakes. The extra channels allow listeners to program in virtually every station they may want to hear, including stations used only for rare types of emergencies, or things they listen to only occasionally. Why Would A Listener Need That Many Channels? Thus, the Uniden radios do have the advantage of larger memories Basically the listener can program until he runs out of memory. As with the Radio Shack and GRE radios, bank sizes are set by the user so that channels aren't wasted. The current bearcat digital scanners, the base/mobile BCD996XT and the handheld BCD396XT scanners, both allow up to 25,000 channels in an unlimited number of banks. This prevents the listener from having to program in unrelated frequencies in the same bank or from wasting leftover channels in a bank. The main improvement is that a scanlist can be dynamically allocated – each scanlist does not need to contain the same number of objects. Just as a bank held a group of channels, a scanlist holds a group of objects. An object can hold a broader range of information. A channel could hold one frequency and some associated text. These “objects” then can be grouped as necessary into 20 “scanlists.” Think of an “object” as analogous to a channel and a “scanlist” as analogous to a bank. The listener can program in up to 1800 “objects”, which can be frequencies, talkgroup ID's, or other information. The Radio Shack handheld PRO-106 and base/mobile PRO-197 and GRE PSR-500 and PSR-600 scanners all use a novel memory management scheme. Memory Managementīoth the uniden, GRE, and Radioshack digital scanners give the listener a great deal of flexibility regarding programming and memory management. No scanners can hear digital television sound signals. Thus, the Uniden models can hear commercial FM broadcast and any unauthorized radio systems that use VHF TV frequencies. The Uniden models offer nearly continuous coverage of the 25-512 MHz spectrum, while the Radio Shack and GRE models stick to the main scanner bands. The Uniden Beacat digital scanner models cover most of the 700 MHz band, while the Radio Shack and GRE models cover very little of it. The radios coverage of 700 MHz systems varies. Frequency CoverageĪll of these digital scanners will tune both types of 800 MHz trunked systems. You may want to check on systems in your area prior to making a purchase. An APCO 25 digital scanner tends to be more expensive than similar radios that lack digital coverage. Luckily most digital systems nationwide are unencrypted, APCO P-25 systems and therefore can be heard with these scanners. Unfortunately, no digital scanner radios can monitor encrypted channels or other digital systems, like EDACS “ProVoice” Digital systems. All current digital trunked scanners can monitor unencrypted Motorola APCO Project 25 (P-25) digital systems. Monitoring digital systems is the main reason why people purchase these scanners, given that they cost significantly more than comparable radios that only receive analog systems. Trying to decide between the BC996XT or Radio Shack PRO-197? Or considering an older model from the used market? This page is intended to be your guide to picking the best digital trunking scanner.
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