Aspidistra ( transmitter ) Aspidistra was a British mediumwave radio transmitter used for black propaganda and military deception purposes against Nazi Germany during World War II . At one time , it was the most powerful broadcast transmitter in the world . Its name - after the popular foliage houseplant - was inspired by the comic song " The Biggest Aspidistra in the World " , best known as sung by Gracie Fields . The transmitter was installed in 1942 at a purpose - built site near Crowborough in southeast England . This was equipped with other mediumwave and shortwave transmitters , which also used the Aspidistra name , being known as ASPI 2 , ASPI 3 , ASPI 4 , etc . However , when the name " Aspidistra " was used on its own it always referred to the original mediumwave transmitter ( ASPI 1 ) . After the war , " Aspidistra " and other transmitters at Crowborough were used for BBC External Service broadcasts to Europe . The station closed in 1982 . Equipment and location . " Aspidistra " broadcast on mediumwave AM with 600 kW of power . The transmitter ( originally 500 kW ) had been built by RCA for WJZ radio in Newark , New Jersey . But at the prompting of Congress spurred on by competition , the Federal Communications Commission later imposed a 50 - kW power limit on all US stations . RCA was therefore glad to sell it overseas and the British Secret Service bought it for £165 , 000 . In addition to its high power , " Aspidistra " could be re - tuned quickly to a new frequency ( position on the dial ) . This was of great use in its secret wartime work and was unusual for a mediumwave transmitter , as they generally operate on a fixed frequency throughout their working life . Its antenna was three guyed masts , each tall . The 1940s Art Deco style transmitter building was in an underground shelter which had been excavated by a Canadian army construction unit . Power for the transmitter was supplied from a single large Crossley - Premier 16 cylinder heavy oil engine . The facility was at King ' s Standing , Maresfield , in the Ashdown Forest , near Crowborough , Sussex . Alongside the original " Aspidistra " , other mediumwave and shortwave transmitters were installed over the years . These included two Doherty 250 kW mediumwave units , whose outputs could be combined to give 500 kW on a single frequency . Two 100 kW shortwave transmitters made by General Electric ( USA ) operated at the Crowborough site from 1943 until the 1980s . Wartime operations . " Aspidistra " went into service on 8 November 1942 , and was in operation throughout the remainder of the war . Impersonation . Starting in 1943 , " Aspidistra " was used to disrupt German nightfighter operations against Allied bombers over Germany . German radar stations broadcast the movements of the bomber streams en route to targets during RAF Bomber Command ' s Battle of Berlin . As part of their strategies to misdirect the German fighters , German - speaking RAF operators impersonated these German ground control operators , sending fake instructions to the nightfighters . They directed the nightfighters to land or to move to the wrong sectors . This interference to enemy RT and WT was known as " Dartboard " As German operational procedures changed to prevent impersonation so the British copied them , bringing in WAAFs when the Germans used female operators . Black propaganda . " Aspidistra " was also used for black propaganda operations , in which the propaganda material is issued from a disguised source . These activities were under the Political Warfare Executive , and directed by Sefton Delmer . In particular , " Aspidistra " aired the broadcasts of " Atlantiksender " and " Soldatensender Calais " , which posed as official German military radio stations in France . Intrusion operations . During Allied air raids , German radio transmitters in target areas were switched off to prevent their use as navigational aids by the enemy . However , such transmitters were very often connected into a network , and broadcast the same content as other transmitters which were not switched off . When a targeted transmitter switched off , " Aspidistra " began transmitting on its frequency , initially retransmitting the German network broadcast as received from an active station . This would cause German listeners to believe the original station was still broadcasting . " Aspidistra " operators would then insert demoralizing false content and pro - Allied propaganda into the broadcast . This content was considered especially effective , as it appeared to be coming from official German sources . These intrusion operations were an early example of a " man in the middle attack " . The first such intrusion was carried out on 25 March 1945 . On 30 March 1945 " Aspidistra " intruded on the Berlin and Hamburg stations , warning that the Allies were trying to spread confusion by sending false telephone messages from occupied towns to unoccupied towns . On 8 April 1945 " Aspidistra " intruded on the Hamburg and Leipzig stations to warn of forged banknotes in circulation . On 9 April 1945 there were announcements encouraging people to evacuate to seven bomb - free zones in central and southern Germany . All these announcements were false . German radio stations tried announcing " The enemy is broadcasting counterfeit instructions on our frequencies . Do not be misled by them . Here is an official announcement of the Reich authority . " However , " Aspidistra " broadcasts included similar announcements , leaving the listeners confused . Post - war operations . Although mainly intended for the military and propaganda transmissions described above , " Aspidistra " was also used during the war for some BBC broadcasts to Europe . After 1945 , " Aspidistra " was used exclusively by the BBC . Frequencies used included 1122 kHz ( 1945 - 1950 ) , 1340 kHz ( 1950 - 1962 ) , 809 kHz ( until 1978 ) , 1295 kHz ( 1962 - 1978 ) and 1088 kHz ( 1972 - 1978 ) . After reorganisation of the mediumwave band in 1978 , the frequencies used were 648 and 1296 kHz . From 1978 , there was a phased transfer of " Aspidistra ' s " broadcasts to a new Foreign Office transmitting station at Orfordness on the Suffolk coast , which was better placed than Crowborough , which is inland . Despite its exclusive post - war use by the BBC , the Crowborough station remained formally in the hands of the Foreign Office ( from 1968 , the Foreign and Commonwealth Office , FCO ) , and its staff were members of the Diplomatic Wireless Service ( later known as the FCO ' s Communications Department and then the Communications Engineering Department ) rather than the BBC . Closure and fate . " Aspidistra " made its final transmission on 28 September 1982 , the honour of pressing the " off " key for the last time going to Harold Robin , the Foreign Office engineer who had been responsible 40 years earlier for purchasing the transmitter in the USA and setting up the station at Crowborough . The station was dismantled in 1984 . Two years later , following extensive modifications , the bunker that housed the " Aspidistra " transmitter was commissioned by the Home Office as one of the 17 sites in England and Wales to be used as seats of regional government in the event of a nuclear attack . From 1988 , Sussex Police used parts of the site , purchasing all of it in 1996 for use as a training facility . In 2007 , Building No . 3 ( known as " the cinema " because of its design similarities with pre - war Art Deco cinemas ) , which had once housed ASPI 3 and ASPI 6 , was designated a Grade II listed structure because of its historic and architectural interest . The designation notes that it is " a remarkably intact and unaltered building through which one can understand its function as an early 1940s transmitter hall " . A reported offer to donate the " Aspidistra " transmitter to London ' s Science Museum was not taken up and it was scrapped . A number of valves ( tubes ) and a large tuning coil were saved by FCO engineers and are now on display in the foyer of the Orfordness station . A notice there says :