From the CIA Archives: An HF Spaced Loop Antenna for Direction Finding

Many thanks to SWLing Post contributor, Grayhat, who shares the following: I stumbled upon a document I found in the "CIA reading room": https://www.cia.gov/library/readingroom/docs/CIA-RDP76-00451R000200010013-1.pdf In short, the document, titled "HF SPACED LOOP ANTENNA" and dating back to 1967, describes the design of a "direction finding" antenna used to find an HF transmitter. The document describes ["]