directional aerial
directional antenna

"If there was time we could hide a bug on you and set up directional aerials."

Directional aerials consist of multiple masts, which need not to be from the same height.

- Broadcasts from a directional aerial to cover Greater Manchester.

The general principle is to rotate a directional aerial and note where the signal is strongest.

Huyghens took a reading and moved the directional aerial a carefully measured distance.

These towers formed a directional aerial for the frequency 234 kHz and until 1980 were 250 metres high.

However in North Essex, Capital was out of range except for people with a very expensive directional aerial.

It was part of the directional aerial for the AFN transmitter described above.

"I could use the spare communicator unit and a couple of directional aerials to pinpoint it, Captain.

The Meacon system involved separate locations for a receiver with a directional aerial and a transmitter.

Unlike the directional aerial for 648 kHz, they were arranged in two parallel rows with three towers in each.

From 1963 until its demolition in November 1993, the mast was used as part of a directional aerial for a mediumwave transmitter.

The directional aerial for 1296 kHz (erected in 1978) consisted of six freestanding steel lattice towers.

A directional aerial array was used to avoid wasting power over the English Channel and to enhance the signal to the east and west.

The transmitter uses directional aerials of four guyed, insulated radio masts which are 270, 276, 280, and 282 metres high.

The longwave transmitter uses a directional aerial with a maximum strength pointing northwest (azimuth: 309 ).

Also the height of the steel framework mast, which was used until 1978 for a directional aerial for 548 kHz was shortened.

Then he plugged in a considerable length of flexible wire and unfolded a tiny, improvised directional aerial with an even tinier booster at its base.

A worldwide network of short-wave stations with directional aerials was established, fulfilling Marconi's dream of global radio communication.

An inflatable rubber dinghy would be carried in the superstructure, and the new directional aerial would be mounted on the after periscope.

The station had two directional aerial (antenna) systems: one for 648 kHz and one for 1296 kHz.

In its time on the AM band, the station had its power increased twice, first to 2,000 watts, and then to 5,000 watts, using a directional aerial system.

These masts were built in 1949 and renovated in the nineties and allow the realisation of a directional aerial with changeable directional characteristic.

Unusually this transmitter also transmits neighbouring services Radio Manchester and Radio Sheffield from separate directional aerials on the mast.

It is also possible to realize directional aerials for mediumwave with cage aerials where some parts of the cage are fed with a certain phase difference.