
More Background...
The USA had for many years had a CB radio service, which by the late
1970's had 40 channels within a frequency allocation of 26.965MHz
to 27.405Mhz , with AM and SSB modes permitted (Amplitude
Modulation and Single SideBand).
It was equipment designed for this american service which found its
way to UK shores to be thoroughly enjoyed, illicitly, by thousands of
'breakers' (CB'ers) between the mid-to-late 1970's and 1981. Media
reports of late-1980 / early-1981 estimated, if memory serves me
rightly, about 250,000 illegal CB operators in the UK at that time.
Something had to be done...
The legal CB service introduced in 1981 - designated CB27/81 -
permitted FM (Frequency Modulation) mode only, on 40 channels within
frequency allocation 27.60125MHz to 27.99125MHz (unique to UK),
leaving all of the equipment already in use rather 'out in the cold'.
In 1988 the UK finally had to provide a CB service within 26.965MHz
to 27.405MHz , but still only FM, for compatibility with other E.E.C.
(European Economic Community) nations - this was designated PR27GB.
However, by this time, many original operators who still had old
equipment (all-be-it in the attic) capable of FM mode on the 'Mid
Shift' had probably either been sidelined by the original legal
system's incompatibility, or drifted away from the new face of CB
since its legal introduction.
It is possible that the introduction of a CB service in the UK, due
mainly to the large-scale illicit use of CB type equipment, was the
thin end of the wedge as regards opening up public access to the
airwaves, as since that provision have come the following allocations,
to mention but a few, in the sphere of personal radio
telecommunications:-
Tequila Sunrise