Radio Scanner Guide
Part 9B: History of Scanner Radios
Curiosity has long motivated hobbyists to buy or build radio that can hear two-way communications. Radio scanners have evolved to store and scan hundreds or thousands of radio frequencies and receive exotic communications like military aircraft and digital systems. However, the first scanners had much more humble begginings, designed mainly to hear local police.
The first scanners were crystal-controlled, like most two-way radios of the day. A separate crystal was needed for each frequency the radio received, at a cost of $5 or more! Most listeners bought less than a dozen crystals, usually to scan their local police or fire department. Hobbyists wishing to collect such receivers for posterity can readily find them used on auction service like eBay.
The first keyboard-programmable receivers became widely available in the early 1980's and quickly replaced crystal-controlled scanner for all but the most limited users. Throughout the 1980's and early 90's, most lower-end scanners only had 8 to 20 channels and often lacked even a search mode! Several portables only displayed the channel number - not even the complete frequency was displayed! Higher-end models set a new standard in scanning. In mid-1986, Radio Shack released the PRO-2004, which stunned the consumer scanner market with 300 channels in 10 scan banks and continous coverage from 25 to 520 and 760 to 1300 MHz, basically everything from Citizens' Band through microwave amateur radio stations! The scanner featured 3 reception modes, including wide-band FM for television and FM broadcast. Search steps could also be selected. Uniden, after buying the Bearcat scanner brand, introduced its own models that could receive the new 800 MHz scanner band. Its sucessors proved even more popular; the PRO-2006, sold from 1990 to 1994, was perhaps the most popular model ever. The Bearcat BC200XLT was a popular handheld introduced in the late 1980's. Both of these models continue to sell well on the used market despite their age and their lack of certain newer features.
Police Go To 800 MHz
Police departments and other public safety users in large cities began migrating to the (then) new 800 MHz bands in the late 1980's. By the mid-90's, police departments in most large cities were on 800 MHz. Some departments made the switch in part to evade scanner listeners, or at least reduce the number of potential listeners and reduce their ability to effectively scan police communications. Many systems employed trunking, a method of where a frequency is assigned from a pool of frequencies each time a user transmits. Trunking is described more extensively in Part 3A: Land Mobile.
The 800 MHz band began appearing in less-expensive scanners as more police departments moved their. Scanners capable of following conversations on systems using trunking appeared in 1997. Uniden's BC235XLT was the first such radio, containing 300 channels in 10 banks. By current standards it was fairly limited; it could only follow Motorola analog systems, listeners whose police and fire departments used other trunking systems had to wait. Also, it could hear only one trunked system at a time or could operate in conventional (non-trunked) mode. Other models soon fixed these limitations.
Police Go Digital
By 2000, 800 MHz systems became almost unbiquitous in medium and large cities throughout the United States. Unfortunately, many departments began using digital voice modulation techniques, which could not be heard on scanners. One format was an open standard developed by Motorola called APCO Project 25 (APCO-25). In 2003, Uniden introducted two scanner models, the handheld BC250D and base/mobile BC785D, that could hear these systems when supplied with an optional digital card. A scanner and card together initially costed around $700, well out of the reach of most hobbyists who were used to paying $150 for a scanner, and even less on the used market. Moreover, these scanners could only follow "mixed-mode" systems, which had an analog control channel and used a lower bandwidth. Radio Shack soon introduced the handheld PRO-96 which fixed these shortcomings and sold for a bit less. Uniden followed with other models, which like the originals, also featured continuous frequency coverage and mode and step selection. As of this writing, though, digital scanners remain expensive compared to their analog counterparts, in part due to patent licensing costs for the digital voice compression technology. In addition, several departments are using other digital protocols which currently cannot be heard on any scanners. Despite these hurdles, the scanning hobby will continue to prosper.
For detailed information on specific scanner models, please refer to Category 6: Radio Scanners Listed By Category.