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- High-frequency_direction_finding abstract "High-frequency direction finding, usually known by its abbreviation HF/DF or nickname huff-duff, is the common name for a type of radio direction finding (RDF) employed especially during World War II. It was used primarily to catch enemy radios while they transmitted, although it was also used to locate friendly aircraft as a navigation aid. The basic technique remains in use to this day as one of the fundamental disciplines of signals intelligence, or "SIGINT", although this is typically incorporated into a larger suite of radio systems and radars instead of being a stand-alone system.The name is something of a misnomer, as the technique works at any frequency. A more accurate term would be "high-speed direction finding", as the primary difference between huff-duff and previous systems was its ability to locate the source of the signal almost instantly. To do this, huff-duff used a set of antennas to receive the same signal in slightly different locations or angles, and then used the slight differences in the signal to display the bearing to the transmitter on an oscilloscope display. Earlier systems used a mechanically rotated antenna (or solenoid) and an operator listening for peaks or nulls in the signal, which took considerable time to determine. Huff-duff's speed allowed it to catch fleeting signals, like those from the German U-Boat fleet.The system was initially developed by Robert Watson-Watt starting in 1926, although many of the practical elements were not developed until the late 1930s. Huff-duff units were in very high demand, and there was considerable inter-service rivalry involved in their distribution. An early use was by the RAF Fighter Command as part of the Dowding system of interception control, and ground-based units were also widely used to feed information to the Admiralty to locate U-Boats. By 1942/43 smaller units were widely available and became common fixtures on most Royal Navy ships. It is estimated that huff-duff contributed directly or indirectly to 24% of all U-Boats sunk during the war.The basic concept is also known by several alternate names, including Cathode-Ray Direction Finding (CRDF), Twin Path DF, and for its inventor, Watson-Watt DF or Adcock/Watson-Watt when the antenna is considered.".
- High-frequency_direction_finding thumbnail HMS_Belfast_-_Huff_Duff.jpg?width=300.
- High-frequency_direction_finding wikiPageExternalLink HFDF1998.pdf.
- High-frequency_direction_finding wikiPageExternalLink histarticles.html.
- High-frequency_direction_finding wikiPageExternalLink xGM-Tech-HFDF.htm.
- High-frequency_direction_finding wikiPageExternalLink HFDF1998.pdf.
- High-frequency_direction_finding wikiPageExternalLink eYGvAm8MMvQ.
- High-frequency_direction_finding wikiPageID "1453216".
- High-frequency_direction_finding wikiPageRevisionID "605802927".
- High-frequency_direction_finding hasPhotoCollection High-frequency_direction_finding.
- High-frequency_direction_finding subject Category:Automatic_identification_and_data_capture.
- High-frequency_direction_finding subject Category:Radio-frequency_identification.
- High-frequency_direction_finding subject Category:World_War_II_Allied_electronics.
- High-frequency_direction_finding subject Category:World_War_II_American_electronics.
- High-frequency_direction_finding subject Category:World_War_II_British_electronics.
- High-frequency_direction_finding comment "High-frequency direction finding, usually known by its abbreviation HF/DF or nickname huff-duff, is the common name for a type of radio direction finding (RDF) employed especially during World War II. It was used primarily to catch enemy radios while they transmitted, although it was also used to locate friendly aircraft as a navigation aid.".
- High-frequency_direction_finding label "High-frequency direction finding".
- High-frequency_direction_finding label "Huff-Duff".
- High-frequency_direction_finding label "Huff-Duff".
- High-frequency_direction_finding label "短波方向探知機".
- High-frequency_direction_finding sameAs DF.
- High-frequency_direction_finding sameAs Huff-Duff.
- High-frequency_direction_finding sameAs Huff-Duff.
- High-frequency_direction_finding sameAs 短波方向探知機.
- High-frequency_direction_finding sameAs m.052srk.
- High-frequency_direction_finding sameAs Q476152.
- High-frequency_direction_finding sameAs Q476152.
- High-frequency_direction_finding wasDerivedFrom High-frequency_direction_finding?oldid=605802927.
- High-frequency_direction_finding depiction HMS_Belfast_-_Huff_Duff.jpg.
- High-frequency_direction_finding isPrimaryTopicOf High-frequency_direction_finding.
