Editing Chain Home (section)

===Upgrades===
Chain Home was the primary radar system of the UK for only a short time. By 1942, many of its duties had been taken over by the far more advanced [[AMES Type 7]] ground-controlled interception ([[Ground control intercept|GCI]]) radar systems. Whereas CH scanned an area perhaps 100 degrees wide and required considerable effort to take measurements, the Type 7 scanned the entire 360-degree area around the station, and presented it on a [[plan position indicator]], essentially a real-time two-dimensional map of the airspace around the station. Both fighters and bombers appeared on the display, and could be distinguished using [[Identification friend or foe]] (IFF) signals. The data from this display could be read directly to the intercepting pilots, without the need for additional operators or control centres.

With the deployment of GCI, CH became the early warning portion of the radar network. To further simplify operations and reduce manpower requirements, the job of plotting the targets became semi-automated. An [[analogue computer]] of some complexity, known as "The Fruit Machine", was fed information directly from the operator console, reading the goniometer setting for bearing, and the range from the setting of a dial that moved a mechanical pointer along the screen until it lay over a selected target. When a button was pushed, the Fruit Machine read the inputs and calculated the X and Y location of the target, which a single operator could then plot on a map, or relay directly over the telephone.<ref name="Vectorsite.net"/>

The original transmitters were constantly upgraded, first from 100&nbsp;kW of the Orfordness system to 350&nbsp;kW for the deployed system, and then again to 750&nbsp;kW during the war in order to offer greatly increased range. To aid in detection at long range, a slower 12.5 pulse per second rate was added. The four-tower transmitter was later reduced to three towers.