In the March/April 2016 Issue…

Our QEX authors touch upon several aspects of Amateur Radio — from circuit behavior, to antenna design, to the directing of energy radiated by antennas.

·         Dr. Ulrich L. Rohde, N1UL, shares a detailed mathematical treatment of the calculation of FM and AM noise signals of Colpitts oscillator circuits.

·         Robert J. Zavrel Jr., W7SX, investigates the mechanisms for the formation of the radiated elevation angle pattern in ground-mounted vertical antennas.

·         Al Christman, K3LC, shows us how to improve the performance of a quarter-wave radiator by adding parasitic elements to form a vertically-polarized Yagi array that is contained entirely within the same foot print as the radiator.

·         Elwood Downey, WBØOEW, takes us through the details of a two-axis satellite tracker that relies entirely on built-in spatial sensors and needs no prior alignment with respect to the Earth’s surface.

QEX is edited by Kazimierz “Kai” Siwiak, KE4PT, (ksiwiak@arrl.org) and is published bimonthly. QEX is a forum for the free exchange of ideas among communications experimenters. The content is driven by you, the reader and prospective author. The subscription rate (6 issues per year) for ARRL members in the United States is $24. Would you like to write for QEX? We pay $50 per published page. Get more information and an Author Guide at www.arrl.org/qex-author-guide. If you prefer postal mail, send a business-size self-addressed, stamped (US postage) envelope to: QEX Author Guide, c/o Maty Weinberg, ARRL, 225 Main St, Newington, CT 06111.

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