Delmer returned to Britain and worked for a time as an announcer for the
German Service of the
BBC. After Hitler broadcast a speech from the
Reichstag offering peace terms, Delmer responded immediately, stating that the British hurl the terms "right back at you, in your evil-smelling teeth". When, in 1945, Delmer learnt that he had been placed on Germany's
Special Search List for arrest after the invasion of Britain, he concluded that it was this broadcast that had put him there. Delmer's instant (but unauthorised) rejection had a great impact on Germany, where
Joseph Goebbels concluded it had to have come from the government. The forthright reaction caused consternation in Berlin, where it was assumed that it could not have been made without official clearance, but the lack of authorisation was later condemned in a House of Commons debate, with MP
Richard Stokes deploring that the response had been made without the authority of parliament. Delmer considered that British wartime attempts to counter German propaganda were misguided, with broadcasts aimed at anti-Nazis who did not need convincing. When he was in a position to do so, he broadcast posing as a fanatical Nazi who was critical of the Nazi leadership, using salacious material about officials'
sadomasochistic orgies, luring in listeners and breaking taboos about insulting Nazi officials. About 40% of German soldiers listened to Delmer's stations; they were among the top three in Munich, and very effective.
Radio stations , Sussex, used for Delmer's
Atlantiksender propaganda broadcasts In September 1940, Delmer was recruited by the
Political Warfare Executive (PWE) to organise
black propaganda broadcasts to Nazi Germany as part of a
psychological warfare campaign. Leonard Ingrams of the PWE gained clearance for Delmer to work for the Political Intelligence Department of the
Foreign Office. The operation joined a number of other "research units" operating propaganda broadcasts, based at
Wavendon Tower (now in
Milton Keynes), but in spring 1941, Delmer was given his own base, a former private house in nearby
Aspley Guise. The concept was that the radio station would undermine Hitler by pretending to be a fervent Hitler-Nazi supporter. Under Delmer's leadership a number of notable people played a part:
Muriel Spark,
Ellic Howe, and Delmer's college friend, the cartoonist
Osbert Lancaster. Some of Lancaster's
Daily Express cartoons were reprinted into booklets aimed at civilians under German occupation and dropped by the
RAF. Delmer's first, most notable success was a shortwave station:
Gustav Siegfried Eins (Gustave Siegfried One), G3 in the Research units. It was "run" by the character "Der Chef", an unrepentant Nazi, who disparaged both
Winston Churchill ("that flatfooted son of a drunken Jew") and the "Parteikommune", the "Party Commune" supporters who betrayed the Nazi revolution. The station name, "Gustav Siegfried Eins" (phonetic alphabet for "GS1") left a question in listeners' minds – did it mean
Geheimsender 1: (Secret Transmitter 1) or
Generalstab 1 (General Staff 1)?
GS1 went on the air on the evening of 23 May 1941 — earlier than intended, to exploit the capture of Hitler's deputy,
Rudolf Hess, in Britain. , a former German writer of detective stories who had fled Nazi Germany, was recruited from a
Pioneer Corps bomb-disposal squad in London and he was the first member of the team to arrive at the discreet house known as "The Rookery" in Aspley Guise. He played "Der Chef". (In Delmer's
autobiography Black Boomerang he acknowledges that "Some of the names of persons mentioned in this book have been camouflaged [ … ]" and Seckelmann was there named "Paul Sanders". ) A journalist, , using the name "Johannes Reinholz", arrived soon after and played the adjutant to "Der Chef". Both men assisted Delmer with the scripts. The recordings were made on disc and taken by courier for transmission from a Foreign Office transmitter at nearby
Signal Hill, Gawcott. Delmer was defended by
Robert Bruce Lockhart, who pointed out the need to reach the sadist in the German nature. GS1 ran for 700 broadcasts before Delmer killed it off in late 1943 with gunfire heard over the radio intimating that the authorities had caught up with "Der Chef". Owing to an error by a non-German-speaking transmitter engineer, the programme was accidentally repeated and "Der Chef's" dramatic on-air murder was broadcast twice. Delmer created several stations and was successful through a careful use of intelligence using gossip intercepted in German mail to neutral countries to create credible stories. Delmer's credit within the intelligence agencies was such that the
Admiralty sought him out to target German submarine crews with demoralising news bulletins. For this, Delmer had access to
Aspidistra, a 500 kW radio transmitter obtained from
RCA in the US (their largest off-the-shelf-model), which Section VIII bought for £165,000. Use of Aspidistra, which began in 1942, was split between PWE, the
BBC, and the
RAF. Delmer's creation was
Deutscher Kurzwellensender Atlantik (or popularly
Atlantiksender). This station used US
jazz (
banned within Germany as decadent) and up-to-date dance music from Germany (extracted via Sweden and RAF courier), as well as an in-house German dance band. Important details on naval procedures came from anti-Nazis identified in
POW camps, whose mail was sifted to create personalised announcements. The presenter ("Vicki") was
Agnes Bernelle, a refugee of part-Jewish origin from Berlin.
Christ the King (G.8) broadcast an attack on the conscience of religious Germans, telling of the horrors of the labour and concentration camps, through a German priest.
Soldatensender Calais Soldatensender Calais ("
Calais Armed Forces Radio Station") was another clandestine radio station Delmer directed at the German armed forces. Based in
Milton Bryan and connected by high-quality telephone lines for transmission from the
Aspidistra transmitter at
Crowborough,
Soldatensender Calais produced
live broadcasts, a combination of popular music, "cover" support of the war, and "dirt" – items inserted to demoralise German forces. Delmer's black propaganda sought to propagate rumours that German soldiers' wives were sleeping with the many foreign workers in Germany at the time. Bernelle, again, was presenter. The station also proved to be popular on the German home front. While the station was in the format of a German military station, it did not pose as an actual Nazi station; but although listeners knew the station was run by the British, they listened to and trusted it, and could use the excuse that they thought it was a legitimate German station if caught listening to it. When
fighting entered Germany itself, black propaganda was used to create an impression of an anti-Nazi resistance movement. At the end of the war in Europe, Delmer advised his colleagues not to publicise the work they had been involved in, lest unrepentant Nazis claim (as had been the case after the
First World War), that they had been defeated by unconscionable methods, rather than on the battlefield. Consequently, former Nazis were able to claim, without contradiction, that they had assisted the fictitious resistance movement; Delmer described this
unintended consequence as a "black boomerang". In December 1945, Delmer was appointed an Officer of the
Order of the British Empire (OBE), with the citation specifying merely that he was "Controller of a Division, Foreign Office". ==Later career and retirement==