Editing Chain Home (section)

===Daventry experiment===
[[File:Jock Herd in Ditton Park radio van.jpg|thumb|This Morris Commercial T-type van, originally used as a portable radio reception testbed, was later refitted for the Daventry Experiment. It is shown in 1933, being operated by "Jock" Herd.]]

The letter was seized on by the Committee, who immediately released £4,000 to begin development.{{efn|Some sources say £2,000.}} They petitioned [[Hugh Dowding]], the [[Air Member for Supply and Research]], to ask the Treasury for another £10,000. Dowding was extremely impressed with the concept, but demanded a practical demonstration before further funding was released.{{sfn|Watson|2009|p=46}}{{sfn|Gough|1993|p=2}}

Wilkins suggested using the new 10&nbsp;kW, 49.8&nbsp;m [[BBC]] [[Borough Hill]] shortwave station in [[Daventry]], Northamptonshire as a suitable ''ad hoc'' transmitter. The receiver and an oscilloscope were placed in a delivery van the RRS used for measuring radio reception around the countryside. On 26 February 1935,{{efn|This, coincidentally, was the same day Hitler officially created the ''Luftwaffe''.<ref>{{cite web |website=History Channel |title=Hitler organizes Luftwaffe |url=http://www.history.com/this-day-in-history/hitler-organizes-luftwaffe}}</ref>}} they parked the van in a field near [[Upper Stowe]] and connected it to wire antennas stretched across the field on top of wooden poles. A [[Handley Page Heyford]] made four passes over the area, producing clearly notable effects on the CRT display on three of the passes.{{sfn|Gough|1993|p=3}} A memorial stone was placed at the site of the test.<ref>{{Cite web|url=https://www.geograph.org.uk/photo/386034|title=Geograph:: Birth of Radar Memorial (C) Jeff Tomlinson|website=www.geograph.org.uk}}</ref>

Observing the test were Watt, Wilkins, and several other members of the RRS team, along with Rowe representing the Tizard Committee. Watt was so impressed he later claimed to have exclaimed: "Britain has become an island again!"{{sfn|Watson|2009|p=46}}

Rowe and Dowding were equally impressed. It was at this point that Watt's previous agitation over development became important; NPL management remained uninterested in practical development of the concept, and was happy to allow the Air Ministry to take over the team.{{sfn|Bowen|1998|p=8}} Days later, the Treasury released £12,300 for further development,{{sfn|Watson|2009|p=46}} and a small team of the RRS researchers were sworn to secrecy and began developing the concept.{{sfn|Bowen|1998|p=8}} A system was to be built at the RRS station, and then moved to [[Orfordness]] for over-water testing. Wilkins would develop the receiver based on the GPO units, along with suitable antenna systems. This left the problem of developing a suitable pulsed transmitter. An engineer familiar with these concepts was needed.{{sfn|Watson|2009|p=47}}