High-frequency direction finding (English Wikipedia)

McNeil, Ian; Day, Lance, eds. (2003). "Robert Watson-Watt". Biographical Dictionary of the History of Technology. Taylor & Francis. p. 1280. ISBN 9780203028292.
Zimmerman, David (2010). Britain's Shield: Radar and the Defeat of the Luftwaffe. Amberley Publishing. p. Chapter 10. ISBN 9781445600611.

ciphermachinesandcryptology.com (Global: low place; English: low place)

Dirk Rijmenants, "Kurzsignalen on German U-boats", Cipher Machines and Cryptology

doi.org (Global: 2^nd place; English: 2^nd place)

Watson Watt, R. A.; Herd, J. F. (February 1926). "An instantaneous direct-reading radiogoniometer". Journal of the Institution of Electrical Engineers. 64 (353): 611–622. doi:10.1049/jiee-1.1926.0051.

duncancampbell.org (Global: low place; English: low place)

"The Evesdroppers" (PDF). Time Out: 8–9. 21 May 1976.

ipellejero.es (Global: low place; English: low place)

"Adcock/Watson-Watt Radio Direction Finding"

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nls.uk (Global: 5,202^nd place; English: 3,120^th place)

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Watson Watt, R. A.; Herd, J. F. (February 1926). "An instantaneous direct-reading radiogoniometer". Journal of the Institution of Electrical Engineers. 64 (353): 611–622. doi:10.1049/jiee-1.1926.0051.

opensub.org (Global: low place; English: low place)

communaute.opensub.org

Pexee le Vrai (16 October 2006). "Le HF/DF (ou Huff-Duff) : Une Invention Française" [HF/DF (or Huff-Duff): A French Invention] (in French). Retrieved 18 July 2014.^{[permanent dead link]}

rl.ac.uk (Global: low place; English: low place)

dittonpark-archive.rl.ac.uk

Gardiner 1962. Gardiner, G. (15 February 1962). "Radio Research at Ditton Park - II: 1922–1927". Radio Research Organization Newsletter (10).

theiet.org (Global: 8,663^rd place; English: 5,646^th place)

digital-library.theiet.org

"The development of a high-frequency cathode-ray direction-finder for naval use"

web.archive.org (Global: 1^st place; English: 1^st place)

The Secret War [Ep7 2/5]: The Battle of the Atlantic. Archived from the original on 2013-12-05.
""High-frequency direction finding"". Archived from the original on 2013-10-04. Retrieved 2011-07-02.

xs4all.nl (Global: 2,158^th place; English: 1,899^th place)

Bauer 2004, p. 1. Bauer, Arthur O. (27 December 2004). "HF/DF An Allied Weapon against German U-Boats 1939–1945" (PDF). Retrieved 2008-01-26.: A paper on the technology and practice of the HF/DF systems used by the Royal Navy against U-boats in World War II
Bauer 2004, p. 2. Bauer, Arthur O. (27 December 2004). "HF/DF An Allied Weapon against German U-Boats 1939–1945" (PDF). Retrieved 2008-01-26.: A paper on the technology and practice of the HF/DF systems used by the Royal Navy against U-boats in World War II
Bauer 2004, p. 4. Bauer, Arthur O. (27 December 2004). "HF/DF An Allied Weapon against German U-Boats 1939–1945" (PDF). Retrieved 2008-01-26.: A paper on the technology and practice of the HF/DF systems used by the Royal Navy against U-boats in World War II
Bauer 2004, p. 7. Bauer, Arthur O. (27 December 2004). "HF/DF An Allied Weapon against German U-Boats 1939–1945" (PDF). Retrieved 2008-01-26.: A paper on the technology and practice of the HF/DF systems used by the Royal Navy against U-boats in World War II
Bauer 2004, p. 6. Bauer, Arthur O. (27 December 2004). "HF/DF An Allied Weapon against German U-Boats 1939–1945" (PDF). Retrieved 2008-01-26.: A paper on the technology and practice of the HF/DF systems used by the Royal Navy against U-boats in World War II
Bauer 2004, pp. 6–7. Bauer, Arthur O. (27 December 2004). "HF/DF An Allied Weapon against German U-Boats 1939–1945" (PDF). Retrieved 2008-01-26.: A paper on the technology and practice of the HF/DF systems used by the Royal Navy against U-boats in World War II
Bauer 2004, pp. 14–15. Bauer, Arthur O. (27 December 2004). "HF/DF An Allied Weapon against German U-Boats 1939–1945" (PDF). Retrieved 2008-01-26.: A paper on the technology and practice of the HF/DF systems used by the Royal Navy against U-boats in World War II
Bauer 2004, p. 16. Bauer, Arthur O. (27 December 2004). "HF/DF An Allied Weapon against German U-Boats 1939–1945" (PDF). Retrieved 2008-01-26.: A paper on the technology and practice of the HF/DF systems used by the Royal Navy against U-boats in World War II
Bauer 2004, pp. 17–19. Bauer, Arthur O. (27 December 2004). "HF/DF An Allied Weapon against German U-Boats 1939–1945" (PDF). Retrieved 2008-01-26.: A paper on the technology and practice of the HF/DF systems used by the Royal Navy against U-boats in World War II

youtube.com (Global: 9^th place; English: 13^th place)

The Secret War [Ep7 2/5]: The Battle of the Atlantic. Archived from the original on 2013-12-05.

High-frequency direction finding (English Wikipedia)

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