Portable HF Transmitting Loop Antenna. November 12, 2004 While HF antennas are not normally known for their small size, magnetic loops can offer quite respectable performance, at the cost of some efficiency and extremely narrow bandwidth.
This tunable magnetic loop antenna is my contribution to the well established art of amateur loop making. It is small and light enough to carry while operating, it disassembles into small but rugged pieces that fit easily in a backpack or gym bag, and it can be tuned from 14 MHz to 30 MHz. Specs in Brief Frequency coverage: 14-30 MHz Efficiency: 32%@14, 54%@18, 66%@21, 78%@25, 87%@30 MHz Bandwidth: 12k@14, 20k@18, 30k@21, 50k@25, 100k@30 MHz SWR: 1.0:1 where tuned Power Handling: tested at 20W PEP Size: 21 inch square plus handle Weight: 4.5 pounds. Ham Radio. Various stuff 1.
Loop antenna: small loop. Amateur Radio II. Antennas. Transducer coils. DIY. DIY. Tech & Robots. Vector Network Analyser. Long range. Spl. Radio. Electronics. Loop antenna. Antennae design. ANTENNA. Conversions/Measurements/Calculators. Research & Reference. Network Tools. Unit 11 Further Mechanical Principles. Software for Electronics & Design. Calculators/Unit Converters. Programs and Calculators. MATH - Calculators. Defining and Calculating Energy. Code Practice QST Source. Code Practice Files. Text Source for W1AW Web Code Practice Files for April 15 and 16, 2014: Text for the 5 to 15 WPM runs comes from December 2012 QST, page 59.
Text for the 20 to 40 WPM runs comes from September 2013 QST, page 49. The various archive files are available from the following links. ARRL - The national association for AMATEUR RADIO. CQ - 'The Authority on Amateur Radio' for more than 65 years. United States Military Telegraph - Morse Code Files. The USMT CW Communicator Ionosphere server!