In post-war America the Government of the day legalised a system of personal two-way radio for the general public that they called "General Mobile Radio Service". The government decreed that GMRS would operate on 467 MHz, an Ultra High Frequency. The only problem with UHF was that in those days the transistor was in its infancy and not in common use and its forerunner, the thermeonic valve, just wasn't up to UHF work, at least cheaply. The other major problem with UHF is that communication is only possible with "line of sight", so that buildings, hills and even trees would interfere with and scatter an UHF signal. Although it was possible to "bounce" an UHF signal off solid objects to effectively "go round corners".

In 1958 the Federal Communications Commission brought in what they called "Class D Citizens Band Radio" which was quickly shortened by the truckers to just CB. The FCC decreed that CB Radio would broadcast on 27 MHz AM (Short Wave) using the lower 23 of the available 80 channels. As CB was intended for just speech and not music, the channel separation of 10 kHz (giving a maximum bandwidth of 10 kHz) would be sufficient for this purpose. This was much better as trees, buildings and hills did not interfere with the signals and "Breakers" were no longer restricted to "line of sight" and could communicate over longer distances. It was even possible to communicate over vast distances by utilising the short wave's ability to skip off the ionosphere and earth right around the world at certain times of the day or night.

Few, if any breakers, knew that at twenty past and ten to each hour Washington broadcast on 5 MHz, 10 MHz, 15 MHz and 20 MHz an ionospheric prediction for the North Atlantic. Using the call sign of WWV a code was broadcast in voice and Morse with N7 being the best and W1 the worst conditions for short wave radio communication between the USA and Europe, with U7 to 1 as somewhere in the middle. In practice, in the U.K., you could never receive a prediction of less than about Whiskey 5 as conditions were so bad that not even the WWV broadcast could get through. However with regular monitoring a radio operator could see how things were developing and thus plan accordingly.

Long distance "Truckers" saw the potential of CB Radio and in the early 60's this communication system caught on. CB really came into its own in 1973 when the price of American petrol rose dramatically and due to world affairs, was also in short supply. To make matters worse for the truckers the American Government imposed a 55 mph speed limit on all roads which meant that journeys would take longer and time, for the truckers, was money. Truckers used the CB to keep in touch with each other and pass on such useful information as where the "Smokeys" were so that a speeding trucker would have time to slow down to a legal speed or circumnavigate the Smokey or which petrol station had petrol. Mr. and Mrs. America and in particular Master and Miss America soon got involved with CB as they too realised that such information was useful to them as well, as was getting directions in a strange area.

The CB was the forerunner of the modern mobile telephone but unlike the telephone, on any one channel, only one person could talk at a time as the act of transmitting cut off the receiving function. So at the end of a transmission the trucker would need to indicate that he had finished speaking and he was waiting for the other guy to speak. Saying "over" was the recognised world wide way of doing this but the truckers thought of something else.

Instead of using their own names, breakers would adopt a pseudonym (handle) which meant that the Smokeys were unable to identify any legal or illegal transmissions.

The truckers developed their own jargon and also adopted the American Police "10 code". Curiously they did not adopt the world recognised "Q" code as used mainly by voice and Morse transmissions, except for the odd one. Incidentally the "Z" code was for teletype transmissions and only the "clever dicks" would use some of them and soon got "high numbers" from other breakers.

By 1977 the initial 23 channel allocation on 27 MHz was grossly overcrowded as CB took America by storm so the FCC allocated a further 17 channels making 40 in all. A further 40 channels above (known as "High Band") and below (known as "Low Band") the legal 40 were grabbed for CB use making 120 in all. Hot on the heels of all this came Power Mics, Kickers/Burners, Roger Bleeps and Sideband. The legal 40 channels, as well as the extra illegal 80 channels, could be extended to 240 by using either the Upper or Lower Sideband. Very quickly specialised "Sideband Rigs" appeared which broadcast at 10 watts or more. These new rigs were particularly suited to skipping around the world for long distance QSL's. This was known as DXing. (Pronounced dee-ex-ing) A trucker in the States could happily chat to a trucker in say Australia although the voice quality was a bit tinny as the sideband was limited to just 5 kHz.

Technical note. The military developed the short wave single sideband transmission for their world wide teletype network. Initially the military transmitters transmitted a low power carrier as well as just one of the sidebands so that the receivers automatic frequency control device had something to lock on to.

A continuous radio frequency radiated at say 27 MHz at a power level of say 10 watts has all the power in that frequency. If the radio frequency is modulated by an audio signal it then develops upper and lower sidebands and the power is spread between both sidebands and the "carrier". Thus the overall signal is radiated at a lower level of power. Which means that with the right equipment you could "hear" just a carrier at a greater distance than a modulated carrier. A "Sideband Rig" doesn't transmit a carrier or one of the sidebands, thus all the power (10 watts) is available in the remaining sideband.

It is still possible to communicate over long distances by skipping using FM but at the time it was not possible to transmit just a sideband of an FM signal. Thus distance was limited by the power output allowed. Nonetheless QSL's between the U.K. and the eastern Europe and beyond were possible with just a 4 watts output. There was no chance of a QSL with the States as they had AM rigs.

To improve their chances of a "copy" truckers started to use Kickers (a radio frequency amplifier) of 25 watts or more. Also various high gain aerials (twigs) were invented to further enhance the performance of a simple 10 watts rig.

A Power Mic seemed to boost the signal further and to do away with having to say "over" at the end of a transmission the Roger Bleep was invented. Actually breakers would say "come back" or "come on" rather than over. The Roger Bleep was just a short whistle which was automatically transmitted when the mic switch was released, thus telling the receiver that the transmitter had finished what he was saying. From just a simple bleep there developed many various signals like a group of bleeps, a wolf whistle or even a short tune which tended to be rather annoying after a copying for even a short while.

In 1965 a London group calling themselves Charlie Bravo Group used low powered walkie talkies around the capital but a series of convictions put them off the air in the latter part of 1970. By then however, a new group had come into existence. The Lima Echo Group used the American 23 channel rigs which had been smuggled in as they were illegal in England. I might add that any AM CB rig is illegal in England and will remain so until the law is changed, which is highly unlikely unless the Yanks invade and conquer England. A perculiar quirk of English law meant that it was only illegal to operate a 27 MHz AM rig as no broadcasting licence had been issued and not to own such a rig.

Then C.W. McCall recorded Convoy and CB took off in England in a big way even if it meant smuggling in thousands of American rigs. Long distance lorry drivers took to CB like a duck to water and the youth of the country followed suit.

Around 1976 a pressure group called Citizens Band Association started to push for a legal CB system in the U.K. suggesting that we adopt the American system.

The Radio Regulatory Department of the Home Office is the body responsible for all radio transmissions in the U.K. and they say who gets what frequency at what mode, for what purpose and what value of power they can use.

On Tuesday 25th April 1978 a great debate took place in the House to discuss Radio Frequencies (Citizens Band Radio). A certain Lord Wells-Pestell stated during the discussion, "I think we have seriously to consider the enormous disadvantages of having a vast army of people who can communicate with each other very easily." I wonder what he was afraid of? An insurrection against the establishment perhaps? As a Labour Government was in power at the time and they were anti-CB, very little happened.

The National Electronics Council commissioned their own report and they came out in favour of CB but not on 27 MHz but at a frequency somewhere between 100 MHz and 500 MHz. Shades of the Yanks all those years previously.

A year later Labour were out and Maggie was in and the Tories were more sympathetic. But during a late night session Timothy Raison of the Home Office stated, "27 MHz was not on because there would be too much interference to other users (model aeroplanes and paging systems) and it would not be allowed under any circumstances." This was rather a strange statement to make as the radio control channels were from 26.975 MHz to 27.245 MHz and the CB channels were 27.60125 MHz and above.

In November 1979 pro CB groups from all over the country got together to unite and lobby for CB.

The National Committee for the Legalisation of Citizens Band Radio decided that CB was to be allowed but on a frequency somewhere between 40 MHz and 500 MHz.

As the authorities discussed and dithered, by 1980, thousands and thousands of illegal 27 MHz AM rigs flooded in to be snapped up by willing customers who it must be said regarded the law as a total and absolute ass.

The then Home Secretary Willy Whitelaw announced in May 1980 that CB would be considered and would be called Open Channel and promised an immediate green paper on the subject. The long awaited document eventually arrived in August with no definite recommendation or conclusion. However the leanings were to a CB system operating on the UHF range of frequencies. This was rejected by the pro CB lobby as being hopelessly impractical and too expensive. A 27 MHz rig would cost under £100 where an UHF rig would be priced out of the pocket of the average potential user. Maybe Willie Whitelaw reasoned that a rig which was too expensive for the average person would prevent the masses from being able to readily communicate with each other. The green paper did promote discussion and only a few of the received replies argued against the 27 MHz range.

The National Committee for the Legalisation of Citizens Band Radio then published their suggestion that CB should take over the old 405 line TV channels of 41 MHz to 47 MHz.

The breakers still favoured 27 MHz AM and in spite of TVI intended to lobby hard for what they wanted and if they didn't get what they wanted they would stay on 27 MHz AM anyway.

The authorities in their infernal wisdom turned down the idea of CB in AM mode in favour of FM although in spite of previous indications they decided to follow the rest of the world and allocate the 40 channels in the 27 MHz range.

26th February 1981, a red letter day for CB, was the day that the government announced the CB would use 27 MHz but in FM mode. This it was claimed would cause less TVI. The government also announced that come the Autumn 934 MHz would also be used for CB. However they also clearly stated that 27 MHz AM would remain illegal and users would face fines, confiscation of equipment and even prison. Very few people invested in the 934 MHz system as firstly the rigs were too expensive and secondly being UHF it would be "line of sight" only.

On 24th June 1981 the Home Secretary gave details of the proposed Citizens Band Radio which would not be known as Open Channel but sensibly as Citizens Band Radio or CB for short. The specifications for the 27 MHz and 934 MHz rigs became available and manufacturers all over the world swung into production. The 27 MHz rigs would be limited to 4 watts output and each had to have an attenuator switch which would reduce the power by 10 dB giving an effective output of just ¼ watt. The purpose of this was to enable the user to abide by the law if their aerial was positioned over 7 metres above the ground. The higher the aerial the greater the range and the government couldn't have the masses communicating with each other willy nilly.

From 2nd November 1981 breakers would be required to buy a £10 licence to operate their FM CB rigs.

Channel 9 was to be kept clear and used for emergencies only. Channel 19 was to be the mobile chat channel, whilst the contact channel was to be channel 14. Once two or more people got in touch on channel 14 they would move over to a vacant channel to conduct their copy.

Other countries followed suit although some stayed with the American system of 27 MHz AM so now we have a world wide network some on FM and some on AM.

For the next five years CB became a craze in the U.K. that very few youngsters resisted and there were so many breakers on channel that it was very difficult to find a clear channel. Eventually the bubble burst and the proliferation of CB shops that had sprung up to service the public demand, closed down.

During that time breakers installed the mobile rigs in their homes and ignored the 7 metres rule by using Silver Rods as well as a variety of other outdoor aerials.

Housebound people welcomed the CB as a means of keeping in touch with the rest of the world without having to resort to the "expensive" telephone.

Many CB clubs sprung up to service the craze and held "Ratchet" nights at pubs and clubs where breakers could meet, dance, drink and talk shop. Some even had a special room set aside for CB talk and some clubs delibarately set up in country pubs, preferably high up, where they had access to a small room (usually an outhouse) into which they set up a DXing suite. Club members could book a session at any time of the day or night to do a bit of DXing. A high gain Silver Rod would be permanently fitted together with a Power Supply Unit, table, comfy arm chair and "brew" making facilities. Although a sideband rig was available, breakers were encouraged to bring their own rig.

Most of these CB clubs would organise some of their members to keep a listening watch on channel 9 to assist with any calls for help. Others would listen out on channels 14 and 19 in case someone called for directions. Out of town truckers and ordinary motorists would often put a call out for directions. Sometimes a local mobile breaker would go out to meet the lost driver and guide them to where they wanted to go.

I know of at least one occassion where a call for help from a parent whose child had gone missing, brought out literally hundreds of breakers to look for and find the missing kid.

Like in any group of people there would be some who let them down by misbehaving on channel and it was these that gave the breaker a bad name. In the main the breaker was a responsible person who followed their own rules even if some of them used an AM rig.

After a distant copy breakers would exchange, via mail, QSL cards which was just a postcard to confirm that the copy had actually taken place. These would be pinned up in breaker's home where he/she could brag to visitors about his QSL's and make them jealous of his/her prowess as a breaker.

Amateur Radio Enthusiasts, (Hams) who had to pass quite stringent exams to get a licence to broadcast, despised the CB fans and looked down on them.

To ensure the maximum transfer of power to the aerial when transmitting or the highest sensitivity of an aerial when receiving, its length in relation to the frequency being used is important. The optimum length of an aerial is half the length of the wavelength being transmitted. Thus for a transmission of 27.60125 MHz (channel 1) the aerial length would need to be 5.434 metres and for 27.99125 MHz (channel 40) 5.358 metres, a difference of 7.6 Cms. Fortunately aerial lengths for the short wave band are not too critical so an aerial of a length of 5.4 metres will do for all 40 channels. The twig wasn't fuusy about the mode and handled AM and FM with equal efficiency.

To calculate the wavelength from the frequency the magic number to remember is 300. Divide the wavelength in metres into 300 and you get the frequency in MHz. Divide the frequency in MHz into 300 and you get the wavelength in metres. The symbol for wavelength is pronounced lambda and looks like an upside down and back to front y.

However it would be impractical to have a 5 metre aerial stuck on the top of a vehicle. For a home based system aerial size isn't too much of a problem unless it is to be inside. Fortunately years before a certain Marconi had worked out that providing you had a dipole of the same length as the aerial, which was earthed, both could be reduced in length to quarter wavelength. The earthed dipole then became a metal mesh of a diameter of a quarter wavelength buried in the ground and was known as the ground plane. For mobile systems the vehicle became the ground plane (earth). Even so a 2½ metre aerial was still too long for a vehicle so the clever people worked out a way of reducing the size even further without loss in performance.

The standard mobile aerial was about a metre in length with the missing 1½ metres simulated electronically. Some twigs were designed to be permanently fixed to the vehicle in a manner similar to ordinary car aerials. Some twigs were mounted in a magnetic base and these could be stuck on top of cars to be easily removed for security's sake when not in use. The "Magmount" (unless it had a powerful magnet) tended to fly off at high traffic speeds.

These excellent mobile aerials were adopted for home base use as they could be installed in the loft of a house thereby no longer indentifying a house as a breakers house by the large twig rigged outside. However they did need a ground plane to take the place of the vehicle, as no one in their right mind would drive a car into a house loft. A few square metres of chicken wire was ideal for the purpose although the inventiveness of breakers knew no bounds. A "Magmount" on a biscuit tin stood on a sheet of metal or on a metal table was a popular device especially for those souls who had their rig and twig in their bedroom where they could rabbit on all night long from the comfort of their beds. To further improve the efficiency of an indoor twig, the ground plane was often connected to the house Earth via a metal cold water pipe or central heating pipes.

Breakers who lived in flats and therefore had no access to a loft and were unable to install an outdoor aerial would find that a large ground plane got underfoot. The solution was to fix a ground plane to the ceiling and suspend the aerial from it. When not in use the aerial could be unscrewed and set aside leaving free and unfettered access in the room. The fact that the aerial was upside down made no difference to its efficiency. Some wag once claimed that he had to stand on his head to receive the signal but nobody really believed that, did they?

Ideally the SWR of a rig/twig set up would need to be checked after installation or change of rig, twig or ground plane. A Standing Wave Ratio of ZERO is the optimum requirement and if achieved for any particular channel then it would be higher for the other channels. It was generally acepted that a SWR of less than about 1.5 was O.K. With a higher SWR you could still get a copy but first of all there was less power leaving the aerial thus reducing the distance of the copy and secondly and most importantly, with a very high SWR and continued use the reflected power back into the transmitter could damage the equipment beyond use without expensive repairs.