HISTORY
of Portishead Radio
Transmitter Sites
Broadcasting to ships had been
taking place since the early days of radio. The Marconi
Company had sites at Poldhu (opened 1901
callsign ZZ) and Caernarvon (opened 1914
- callsign MUU) which broadcast to ships on long wave,
giving extended range.
Devizes
No long-range system existed until 1919 when the GPO and
the Marconi Wireless Telegraph Company agreed to convert
a redundant Imperial Wireless chain receiving station at Devizes
in Wiltshire for long-range maritime use. Comprising a
6-Kilowatt valve transmitter, station ''GKT'
opened for service early in 1920 with a guaranteed range
of 1,500 miles, the receiver and operational staff being
on the same site.
By 1924 it became necessary to expand
the station at Devizes to cope with the increased demand.
The GPO constructed a second long-wave transmitter with
the additional callsign of GKU and moved the receiver and
operational site to Highbridge. By 1926, experiments on
short wavelengths had established that world-wide
communication could take place and, in the same year, the
GPO installed the first maritime short-wave
transmitter at Devizes. (rapid expansion of the
service and limited space at Devizes led to the
requirement for a new transmitter site and ultimately
closure of Devizes).
Portishead
Initial tests of the new short-wave system proved
outstandingly successful, and it became necessary to
construct a brand new transmitting station.
This station was to be located at Portishead,
near Bristol, and thus in
1927 Portishead Radio was born.
Three
long-wave transmitters were installed, followed in 1929
by a new short-wave transmitter. Existence of the
Portishead site ultimately resulted in the closure of the
Devizes station. Long-wave transmissions ceased from
Portishead in 1959. In 1970 radiotelephony service
transferred from Baldock to Portishead.
The Portishead transmitting
site was closed in 1978, leaving the sites at
Leafield and Ongar, operating alongside the main
transmitting site at Rugby. However, the famous name of
'Portishead Radio' was maintained to provide the maritime
community with a familiar and well-known service.
Other
sites - Rugby, Ongar, Leafield
The GPO had transmitter
sites at a number of locations around the UK which provided point-to-point
transmission facilities for long-range international telephone calls.
At undersea cables came into use followed by satellite communications,
some of the powerful transmitters at these sites became redundant, opening
the way for them to be transferred for maritime use (and contributing
to the demise of the Portishead transmitter site with its older, less
powerful transmitters.
These sites also provided service for other users
(such as Reuters) and, as use of short-wave declined, so more transmitter
capability became available at Rugby and the sites at Ongar and then
Leafield became redundant, eventually closing.
Another site associated
with maritime communications was Baldock
Radio which provided the
maritime world with it's HF radiotelephony links until 1970. Today Rugby
provides the entire HF maritime transmitter capability.
Rugby
Radio/GBR
A Special mention is warranted for GBR.
Opened in 1926 on 16kc/s, GBR's purpose was for
long-range broadcasts to ships. More recent Radio
Officer's remember the station for it's time signals. The famous keying of the GBR callsign in Morse would
cause lights in the vicinity of the radio station to
illuminate in time to the keying.
Laterllu the transmissions format from GBR changed to teletype broadcasts for submarines. With the removal of this role from British Telecom's control and the encroachment of the Rugby town suburbs, GBR ceasd to be. |