<div dir="ltr"><p style="margin:0.5em 0px;line-height:22.4px;color:rgb(37,37,37);font-family:sans-serif;font-size:14px"> </p><table class="" style="width:22em"><tbody><tr><th style="text-align:center;font-size:125%" colspan="2"><br></th></tr><tr><td style="text-align:center" colspan="2"><a class="" href="https://en.wikipedia.org/wiki/File:ALGROS2.JPG"><img width="133" height="199" alt="ALGROS2.JPG" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/51/ALGROS2.JPG/300px-ALGROS2.JPG" style="margin-right: 0px;"></a> <img src="cid:ii_15282ca6640d521e" alt="Imagem inline 2" width="130" height="101" style="margin-right: 0px;"></td></tr></tbody></table><p><span style="font-weight:bold;text-align:center">Alfred J. Gross </span>(W8PAL) invented the CB radio in 1945</p><p>The citizens band radio service originated in the United States as one of several personal radio services regulated by the <a title="Federal Communications Commission" href="https://en.wikipedia.org/wiki/Federal_Communications_Commission">Federal Communications Commission</a> (FCC). These services began in 1945 to permit citizens a radio band for personal communication (e.g., radio-controlled model airplanes and family and business communications). In 1948, the original CB radios were designed for operation on the 460–470  Megacycle UHF band.<sup class="" id="cite_ref-2"><a href="https://en.wikipedia.org/wiki/Citizens_band_radio#cite_note-2">[2]</a></sup> There were two classes of CB radio: &quot;A&quot; and &quot;B&quot;. Class B radios had simpler technical requirements, and were limited to a smaller frequency range. <a title="Alfred J. Gross" href="https://en.wikipedia.org/wiki/Alfred_J._Gross">Al Gross</a> established the Citizens Radio Corporation during the late 1940s to manufacture Class B handhelds for the general public.<sup class="" id="cite_ref-3"><a href="https://en.wikipedia.org/wiki/Citizens_band_radio#cite_note-3">[3]</a></sup></p><p><a title="Ultra-high frequency" class="" href="https://en.wikipedia.org/wiki/Ultra-high_frequency">Ultra-high frequency</a> (UHF) radios, at the time, were neither practical nor affordable for the average consumer. On September 11, 1958<sup class="" id="cite_ref-4"><a href="https://en.wikipedia.org/wiki/Citizens_band_radio#cite_note-4">[4]</a></sup> the Class D CB service was created on 27 Megacycles, and this band became what is popularly known today as &quot;Citizens Band&quot;. There were only 23 channels at the time; the first 22 were taken from the former <a title="Amateur radio service" class="" href="https://en.wikipedia.org/wiki/Amateur_radio_service">amateur radio service</a> 11-meter band, and channel 23 was shared with radio-controlled devices. Some hobbyists continue to use the designation &quot;11 meters&quot; to refer to the Citizens Band and adjoining frequencies. <a title="Part 95 (page does not exist)" class="" href="https://en.wikipedia.org/w/index.php?title=Part_95&amp;action=edit&amp;redlink=1">Part 95</a> of the Code of Federal Regulations regulates the Class D CB service, on the 27 MHz band, since the 1970s and continuing today.<sup class="" id="cite_ref-5"><a href="https://en.wikipedia.org/wiki/Citizens_band_radio#cite_note-5">[5]</a></sup> Most of the 460–470 MHz band was reassigned for business and public-safety use; Class A CB is the forerunner of the <a title="General Mobile Radio Service" href="https://en.wikipedia.org/wiki/General_Mobile_Radio_Service">General Mobile Radio Service</a> (GMRS). Class B CB is a more distant ancestor of the <a title="Family Radio Service" href="https://en.wikipedia.org/wiki/Family_Radio_Service">Family Radio Service</a>. The <a title="Multi-Use Radio Service" href="https://en.wikipedia.org/wiki/Multi-Use_Radio_Service">Multi-Use Radio Service</a> is another two-way radio service in the <a title="Band III" href="https://en.wikipedia.org/wiki/Band_III">VHF high band</a>. An unsuccessful petition was filed in 1973 to create a Class E CB service at 220 MHz, which was opposed by amateur radio organizations.<sup class="" id="cite_ref-6"><a href="https://en.wikipedia.org/wiki/Citizens_band_radio#cite_note-6">[6]</a></sup> and others. There are several other classes of personal radio services for specialized purposes (such as <a title="Remote control" href="https://en.wikipedia.org/wiki/Remote_control">remote control</a> devices).</p><p>During the 1960s, the service was popular among small businesses (e.g., electricians, plumbers, carpenters), <a title="Truck driver" href="https://en.wikipedia.org/wiki/Truck_driver">truck drivers</a> and radio hobbyists. By the late 1960s advances in <a title="Solid state (electronics)" class="" href="https://en.wikipedia.org/wiki/Solid_state_(electronics)">solid-state</a> electronics allowed the weight, size, and cost of the radios to fall, giving the public access to a communications medium previously only available to specialists.<sup class="" id="cite_ref-ind_7-0"><a href="https://en.wikipedia.org/wiki/Citizens_band_radio#cite_note-ind-7">[7]</a></sup> CB clubs were formed; a <a title="CB slang" class="" href="https://en.wikipedia.org/wiki/CB_slang">CB slang</a> language evolved alongside <a title="Ten-code" href="https://en.wikipedia.org/wiki/Ten-code">10-codes</a>, similar to those used in <a title="Emergency service" href="https://en.wikipedia.org/wiki/Emergency_service">emergency services</a>.</p><p style="margin:0.5em 0px;line-height:22.4px;color:rgb(37,37,37);font-family:sans-serif;font-size:14px"><br></p><p style="margin:0.5em 0px;line-height:22.4px;color:rgb(37,37,37);font-family:sans-serif;font-size:14px">Fonte: Wikipedia</p></div>