Experimental Station W6XBC operated by Dr. A.H. Schermann in Yuma AZ operated at 27.1 MHz. (W6XBC stood for Experimental Broadcaster 6th radio district).
The FCC is established by an Act of Congress commonly known as the Communications act of 1934. Radio "services" are created in three categories, Broadcast, Public & Safety/Special.
Forward thinking Herbert Brooks, W9SDG of Port Wing WI. writes a letter to the editor of QST magazine and it is published in November 1938 describing a theoretical "Citizens Radio Service" nearly identical to what we know today.
World War II spurs development of 27MHz equipment for use in tanks and beachhead landing networks. The BC-1335 an 18 tube 6 or 12v 4 Watt military unit weighing 25 lbs. was a forerunner of things to come.
Speaking at the FCC frequency allocation hearings held during late 1944, Rear Admiral Stanford C. Hooper presents a draft of an obscure project proposing a band of frequencies be set aside for veterans returning home from WWII. The thought was that many returning vets possessed the technical knowledge, ideas & skills to create a new industry based on personal communications.
In January of 1945, just after Admiral Hoopers plan was announced, the FCC took unusually rapid action in announcing CB docket # 6651. The FCC commissioner E. K. Jett outlines in the July issue of the Saturday Evening Post his vision for the CB service.
Doctors use 27MHz, operating diathermy medical equipment on a band of frequencies between 26.96 to 27.28
The Atlantic City Conference - Amateurs lose parts of 10 meters and 20 meters, but will gain a new band at 15 meters in 1952. To compensate for the loss, the FCC allows use of the 11 meter band (26.96 to 27.23 Mc) on a shared basis with Industrial, Scientific and Medical devices. Class D radio for shared professional use introduced at 465MHz UHF. Doctors are permitted to continue using 27MHz.
Licensed February 1947, radio Engineer John M. Mulligan fires up W2XQD using homemade equipment he was able to maintain spotty communications on temperamental UHF channels for a distance of 5 miles.
On March 23 1948 the FCC issued the first certificate of type approval for equipment to be used in the Citizens Radio Service at 465 megacycles. The model
100-B designed by Citizens Radio Corporation becomes the worlds first type approved CB radio.
Firestone Tire Company granted experimental license W10XXD on 27.255MHz using two 3Watt transmitters. The experiments Firestone conducted are lost amid the company's corporate records but they may have been testing fore-runners of modern CB gear.
- Laying practically dormant for a decade, 465MHz Class D service deemed a failure, the search is on for a replacement band.
FCC Docket #11994 proposes reallocating Class D in the very underused 11 meters Ham band 26.96-27.23 MHz (USA-only). At this time there was little business/military use of 27MHz and model control on
27.255 was inadequate, being shared with paging and other services.
11th Sept 1958
The 11 meters ham band is reassigned to models and Class D Citizens' Band radio. The band is divided into 10kHz channels, the first channel bounded by 26.96 and 26.97 with the carrier frequency centered at 26.965 - and 27.225 being the last channel center - 27 channels in all. Models were allocated 5 new channel centers, 50kHz apart, the outer channels being 35kHz away from the band edges. 22 Class D channels were arranged around the model channels that later became known as channels 3A, 7A, 11A, 15A and 19A.
The old model channel at 27.255 was allocated as a further 23rd Class D channel, a shared frequency that remains as the 6th model channel also. The Business Band above 27.23 couldn't yet be used for CB apart from
channel 23 - the two-channel gap between 22 and 23 gave rise to pirate channels 22A and 22B.
(27.235 22A before becoming 24 in 1977)
(27.245 22B before becoming 25 in 1977)
Mr. Donald L. Stoner publishes an article in Radio & TV News that includes design details on constructing a homemade CB radio transceiver. The schematic, component layout and alignment instructions are all included, this spurs many individuals to build their own version. This movement is picked up quickly by the fledgling industry and commercially produced kits become available almost overnight.
1st Jan 1977
More CB channels added - there was talk of having 99 channels up to 27.995 but it was decided not to allow a span of more than 440kHz - to prevent intermod breakthrough to any 455kHz receiver Intermediate Frequency stages. The business band lost 27.23 - 27.41, to new CB channels 24 to 40. Channels 24 and 25 filled in the reclaimed gap between 22 and 23 (which is why the order is strange), and channels 26 to 40 continued from 27.265 to 27.405 - by coincidence the first two decimal places match the channel number. The five newer model freqs are now part of an allocation from 26.96 to 27.28 . In the USA, channel 23 is still the "Blue" model channel.
27.235 24 *new*
27.245 25 *new*
27.265 26 *new*
27.405 40 *new*
Thank You, Tom Kneitel, K2AES (ex-2W1965) for providing historical data. Also Meg A Hertz for frequency data. Without their help this page would not be possible.