Infobox Magazine title QEX image file image size image caption editor Larry Wolfgang, WR1B editor title Editor frequency Bimonthly circulation category Amateur radio company publisher American Radio Relay League firstdate December, 1981 country USA language English language English website http www.arrl.org qex www.arrl.org qex issn QEX is a bimonthly magazine published by the American Radio Relay League . The magazine covers topics related to amateur radio and radio communication experimentation. The magazine features advanced technical articles on the theory, design, and construction of radio antennas and equipment. The magazine is published in English language English and has a worldwide subscription base. QEX began in December, 1981 as a magazine carrying the subtitle ARRL Experimenter s Exchange . The founding editor was Paul Rinaldo, W4RI, who also contributed many technical articles to the ARRL membership journal, QST . In January, 2000, the American Radio Relay League purchased a competing publication, Communications Quarterly from CQ Communications, Inc. who also publish the CQ Amateur Radio magazine , and merged the contents into QEX . The magazine s subtitle changed to A Forum for Communications Experimenters . ref name history Wolfgang, Larry 2007 . http www.arrl.org qex history The History of QEX . American Radio Relay League web site. Retrieved Sep. 25, 2007. ref Citations reflist Category Amateur radio magazines Category American magazines amateur radio stub hobby mag stub ... more details
The regenerative loop antenna can consist of a tuned signal winding on an open X frame with a feed back winding in close proximity. High effective gain is achieved, for example by placing this feedback winding in the drain circuit of a JFET junction field effect transistor . An antenna of this type employing vacuum tube s was constructed by Vladimir Zworykin in the 1920s. Sources ARRL publication QEX, January February 2007, pages 45 46. External Links An example of a regenerative loop antenna http billyoungradio.com Antenna Types Category Radio frequency antenna types radio comm stub ... more details
Refimprove date December 2009 A crystal filter is a special form of quartz crystal used in electronics systems, in particular Telecommunication communications devices. It provides a very precisely defined centre frequency and very steep bandpass characteristics, that is a very high Q factor Q factor &mdash far higher than can be obtained with conventional lumped circuit s. A crystal filter is very often found in the Superheterodyne receiver intermediate frequency IF stages of high quality radio receiver radio receivers . Cheaper sets may use ceramic filters which also exploit the piezoelectric effect , or tuned LC circuit s. The use of a fixed IF stage frequency allows a crystal filter to be used because it has a very precise fixed frequency. The most common use of crystal filters, is at frequencies of 9 MHz or 10.7 MHz to provide selectivity in communications receivers, or at higher frequencies as a roofing filter in receivers using up conversion. Ceramic filters tend to be used at 10.7 MHz to provide selectivity in broadcast FM receivers, or at a lower frequency 455 kHz as the second intermediate frequency filters in a communication receiver. Ceramic filters at 455 kHz can achieve similar bandwidths to crystal filters at 10.7 MHz. Very high quality IF filters, called crystal ladder filters, can be constructed by using serial arrays of crystals, ref Horst Stader and Jack A. Hardcastle, Crystal Ladder Filters for All , QEX , pp.14 18 Nov Dec 2009, http www.arrl.org files file QEX Next Issue Nov Dec 2009 QEX Nov Dec 09 Feature.pdf ref References Reflist DEFAULTSORT Crystal Filter Category Linear filters Category Wireless tuning and filtering Category Signal processing filter Electronics stub ... more details
This is a list of magazines that focus on topics related to amateur radio . It is not complete by any means. class wikitable sortable style border 1px white font size 100 margin left 1em Magazine Country Language Frequency Published 73 magazine 73 USA English Monthly 1960 2003 Amateur Radio AUS English Monthly 1932 present Amateur Radio IND English Quarterly Break In NZL English Bimonthly 1927 present CQ Amateur Radio USA English Monthly 1945 present CQ DL GER German Monthly CQ ham radio JPN Japanese Monthly 1946 present CQ PA NLD Dutch Monthly 1951 present CQ QSO BEL Dutch, French Bimonthly CQ VHF Magazine USA English Quarterly Electric Radio USA English Monthly 1989 present Electron NLD Dutch Monthly 1945 present Electronics Illustrated USA English Monthly 1959 1961 Five Nine JPN Japanese Monthly Funkamateur GER German Monthly Hagal ISR Hebrew 5 6x per year HamFormosa TWN Chinese Monthly Ham Radio Magazine ham radio USA English Monthly 1968 1990 Ham s CQ CHN Chinese Quarterly ???? 2006 HB Radio SUI German Monthly K9YA Telegraph USA English Monthly 2004 present Modern Electrics USA English Monthly 1908 1913 National Contest Journal USA English Bimonthly 1973 present Old man magazine old man SUI German, Italian, French Monthly 1932 2007 Onda corta MEX Spanish Bimonthly 1932 present Practical Wireless UK English Monthly 1932 present Radio, Fernsehen, Elektronik GER German Monthly ru Radio RUS Russian Monthly 1924 present Radioamateur Magazine FRA French Monthly 2008 present i Radioamateur UKR Ukrainian, Russian Monthly 1993 present Radio News USA English Monthly 1917 1971 R di technika HUN Hungarian Monthly Unknown Radio ZS RSA English Quarterly Unknown QEX USA English Bimonthly 1981 present QTC Amat rradio SWE Swedish Monthly QSP PRT Portuguese Monthly QST USA English Monthly 1915 present RadCom UK English Monthly 1913 present Radio REF FRA French Monthly Radioamat ri FIN Finnish Monthly Radiocomunica ii i Radioamatorism ROU Romanian Monthly ... more details
, Part 1 , QEX , ARRL, July Aug. 2002 http www.flex radio.com Data Doc qex1.pdf ref ref A Software Defined Radio for the Masses, Part 2 , QEX , ARRL, Sept Oct 2002 http www.flex radio.com Data Doc qex2.pdf ref ref A Software Defined Radio for the Masses, Part 3 , QEX , ARRL, Nov. Dec. 2002 http www.flex radio.com Data Doc qex3.pdf ref ref A Software Defined Radio for the Masses, Part 4 , QEX ... more details
QEX Cordesses cite web url http lionel.cordesses.free.fr gpages sstv.html title Some Thoughts on Real Time SSTV Processing. author Cordesses, L. and R F2DC work QEX year 2003 accessdate September 2 ... more details
File Car radio antenna extended portrait.jpeg thumb 150px right Whip antenna on car File Half Wave Dipole.jpg thumb 150px right Half wave dipole antenna File Canberra Deep Dish Communications Complex GPN 2000 000502.jpg thumb 150px right Large parabolic antenna for communicating with spacecraft File Antenna.jpg thumb 150px right Rooftop directional antenna s, typical for use at Very High Frequency VHF and Ultrahigh frequency UHF frequencies An antenna or aerial is an electrical device which couples radio waves in free space to an electrical current used by a radio receiver or transmitter. In reception, the antenna intercepts some of the power of an electromagnetic radiation electromagnetic wave in order to produce a tiny voltage that the radio receiver radio receiver can amplify. Alternatively, a radio transmitter will produce a large radio frequency current that may be applied to the terminals of the same antenna in order to convert it into an electromagnetic wave radio wave radiated into free space. Antennas are thus essential to the operation of all radio equipment, both transmitter s and Receiver radio receiver s. They are used in systems such as radio broadcasting radio and television broadcasting , two way radio , wireless LAN , mobile telephony , radar , and satellite communications . Typically an antenna consists of an arrangement of metallic conductor material conductor s or elements with an electrical connection often through a transmission line to the receiver or transmitter. A current forced through such a conductor by a radio transmitter will create an alternating magnetic field according to Amp re s law . Or the alternating magnetic field due to a distant radio transmitter will induce a voltage at the antenna terminals, according to Faraday s law , which is connected to the input of a Receiver radio receiver . In the so called far field , at a considerable distance away from the antenna, the oscillating magnetic field is coupled with a similarly oscill ... more details
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