A radio antenna in the north of the island will still be governed by a time restriction, planners have said.

The crossed field antenna was originally granted planning permission for a site on the Jurby Industrial Estate in 2012 for a limited period of five years.

But when the go-ahead was given to raise the height by two metres, following the construction of the adjacent Motor Nuseum, the time limit disappeared.

Jurby Commissioners’ clerk, John Quayle, said the local authority had objected to the original plans, saying it did not fit in with the area, was near to the school and might end up being raised in height.

’In 2015 the application was to increase the height. That was approved but in that approval it was also made permanent as a structure and it’s just come to light recently,’ he said.

The planning applications were by island-based company Communications Dynamics Ltd which ran tests on a similar conical crossed field antenna in Silsden in Yorkshire before relocating to the Isle of Man.

Makers of the antenna, which was patented in the 1980s, claim it can work more efficiently than an equivalent standard ’monopole’ transmitter. Egypt-based Kabbary Antenna Technology Co says on its web site: ’Our new company, Communications Dynamics Limited in the Isle of Man has completed and started the operation of the First Directional MW / LF / ELF CFA at Jurby site in January 2017 , with excellent signal level and very broad bandwidth.’

By way of ’explanation’ it offers: ’The oscillation of an energy envelope upon the non-linear qualities of bent-space would create a series of zero-crossings that drift in absolute amplitude per crossing, in proportion to the energy-density of the local expanding Universe.’

A planning department spokesman said the five year time limit was replaced by a requirement to clear the site if the antenna became redundant. A five year time limit was, however, placed on the ancillary buildings, without which the antenna could not operate, after that a new application will be needed.