Country: United Kingdom Region: Cornwall
Latitude: 50° 23' 12" N Longitude: -6° 50' 53" E
Area use / Military Branches: Active
50°23'1"N 5° 8'57"W Penhale Sands http://www.flickr.com/photos/john_fielding/30249745011
One of the DHFCS HF radio stations (check 2.MoD Forest Moor for more info).
It has direction findng equipment installed such as the Plessey Pusher (AN/FRD-13) array; however it is not clear if there are actually antennas on it.
There are 2 of these on the site, known that a loop antenna has a figure-of-eight pattern with two nulls 180 degrees apart in the plane of the loop.
For direction finding this is of limited value as the station being received could lie either in front or behind the antenna. However it is also known that in an array where two loop antennas are set at 90 degrees to one another, their outputs may be combined in such a way as to produce a cardioid (heart-shaped) pattern with a simgle null. Thus determination of bearing is possible.
Further more, when a number of loops are arranged in a line, and their outputs combined via a phasing system, the response lobes can be electrically steered up to about +/-30 degrees. I would fully expect that these two principles are used in this array to give a single null that may be electrically steered to any bearing. The bearing may even be spinning around constantly, the receiver output being displayed on a synchronised circular timebase to show in real time the antenna response pattern relative to the bearing of the received station. Several receivers and displays could use the output of the array simulateously.
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