About the Cover Sample output images and a test INCLUDING: shot (phase/frequency-detector output) of the inexpensive QEX (ISSN: 0886-8093) is published bimonthly in January, March, May, July, September, and WEFAX down-converter. November by the American Radio Relay League, A 225 Main Street, Newington CT 06111-1494. Yearly subscription rate to ARRL members is $22; nonmembers $34. Other rates are listed below. Periodicals postage paid at Hartford, CT and at R R additional mailing offices. POSTMASTER: Form 3579 requested. L Send address changes to: QEX, 225 Main St, Newington, CT 06111-1494 Issue No 199 Features David Sumner, K1ZZ Publisher Doug Smith, KF6DX 3 The ATR-2000: A Homemade, High-Performance HF Editor Transceiver, Pt 1 Robert Schetgen, KU7G By John B. Stephensen, KD6OZH Managing Editor Lori Weinberg Assistant Editor 16 A Homebrew Multiband Yagi Zack Lau, W1VT Contributing Editor By Johan Van de Velde, ON4ANT Production Department Mark J. Wilson, K1RO Publications Manager 20 A Giant LF Loopstick Michelle Bloom, WB1ENT By Richard Q. Marris, G2BZQ Production Supervisor Sue Fagan Graphic Design Supervisor David Pingree, N1NAS 23 A High-Performance Homebrew Transceiver: Part 5 Technical Illustrator By Mark Mandelkern, K5AM Joe Shea Production Assistant Advertising Information Contact: 38 High-Quality SSB Audio John Bee, N1GNV, Advertising Manager 860-594-0207 direct By Bob Heil, K9EID 860-594-0200 ARRL 860-594-0259 fax Circulation Department Debra Jahnke, Manager 45 A Class-B Audio Amplifier Kathy Capodicasa, N1GZO, Deputy Manager Cathy Stepina, QEX Circulation By Parker R. Cope, W2GOM/7 Offices 225 Main St, Newington, CT 06111-1494 USA Telephone: 860-594-0200 Telex: 650215-5052 MCI 48 A Synthesized Down-Converter for 1691-MHz WEFAX Fax: 860-594-0259 (24 hour direct line) By Jim Kocsis, WA9PYH e-mail: [email protected] Subscription rate for 6 issues: In the US: ARRL Member $22, nonmember $34; Columns US, Canada and Mexico by First Class Mail: ARRL member $35, nonmember $47; Elsewhere by Surface Mail (4-8 week delivery): 56 RF By Zack Lau, W1VT 60 Letters to the Editor ARRL member $27, nonmember $39; Elsewhere by Airmail: ARRL member $55, 59 Upcoming Technical 63 Next Issue in QEX nonmember $67. Conferences Members are asked to include their membership control number or a label from their QST wrapper when applying. Mar/Apr 2000 QEX Advertising Index In order to ensure prompt delivery, we ask that you periodically check the address information on your mailing label. If you find any inaccura- Almost All Digital Electronics: 64 Noble Publising: Cov II cies, please contact the Circulation Department Astron: Cov IV No Walls Inc: 37 immediately. Thank you for your assistance. Atomic Time, Inc.: 55 Renaissance Radio: 47 Copyright ©2000 by the American Radio Relay Communications Concepts Inc.: 15 Shoc: 62 League Inc. For permission to quote or reprint Communications Specialists, Inc: 15 Tucson Amateur Packet Radio Corp: 63 material from QEX or any ARRL publication, send Computer Aided Technologies: 63 TX RX Systems Inc.: 55 a written request including the issue date (or book title), article, page numbers and a description of HAL Communications: Cov III Universal Radio, Inc.: 44 where you intend to use the reprinted material. Roy Lewallen, W7EL: 44 Z Domain Technologies, Inc: 37 Send the request to the office of the Publications Nemal Electronics International, Inc.: 44 Manager ([email protected]) Mar/Apr 2000 1 THE AMERICAN RADIO A RELAY LEAGUE R R Empirically Speaking L The American Radio Relay League, Inc, is a noncommercial association of radio amateurs, organized for the promotion of interests in Amateur Radio communication and experimentation, for the establishment of networks to provide Welcome to the combined QEX/ In this QEX/Communications communications in the event of disasters or other emergencies, for the advancement of radio art Communications Quarterly. Special Quarterly and of the public welfare, for the representation greetings go to those of you who haven’t We begin with a look into John of the radio amateur in legislative matters, and been getting QEX. As a Forum for for the maintenance of fraternalism and a high Stephensen, KD6OZH’s home-brew standard of conduct. Communications Experimenters, you rig, the ATR-2000. This synthesized, ARRL is an incorporated association without will find this magazine to be a level 20-meter monobander uses a common- capital stock chartered under the laws of the medium for the exchange of ideas and state of Connecticut, and is an exempt organiza- sense approach to reasonably large tion under Section 501(c)(3) of the Internal information about a wide variety of receiver dynamic range on HF. John’s Revenue Code of 1986. Its affairs are governed topics. We are here to help document by a Board of Directors, whose voting members circuits address the needs for better are elected every two years by the general advanced work in telecommunications phase-noise performance and reduc- membership. The officers are elected or and support efforts to forward the state tion of receiver-induced QRM. appointed by the Directors. The League is of the art. We also embrace the cause of noncommercial, and no one who could gain Johan Van de Velde, ON4ANT, has financially from the shaping of its affairs is technical education and try to solicit and produced some interlaced, multiband eligible for membership on its Board. select a mixture of articles encom- Yagis that ought to interest DXers and “Of, by, and for the radio amateur, ”ARRL numbers within its ranks the vast majority of passing a broad range of skill levels. anyone else who wants a strong signal. active amateurs in the nation and has a proud Here we are much less formal than QST, The tradeoffs among element spacing, history of achievement as the standard-bearer in for example. Authors need not explain boom length and electrical parameters amateur affairs. A bona fide interest in Amateur Radio is the every detail, nor provide complete bills are duly considered in Johan’s com- only essential qualification of membership; an of materials; they exchange ideas puter modeling. Richard Marris, Amateur Radio license is not a prerequisite, through their articles and letters. I G2BZQ, is working on a somewhat although full voting membership is granted only to licensed amateurs in the US. think this isn’t so different from what smaller scale; he brings us his “giant” Membership inquiries and general corres- you’ve come to expect. loopstick antenna. It’s good for broad- pondence should be addressed to the cast and other LF reception where larger administrative headquarters at 225 Main Street, To Communications Quarterly con- Newington, CT 06111 USA. tributors, whom we’re also quite antennas aren’t practical. Mark Mandelkern, K5AM, wraps up Telephone: 860-594-0200 happy to have aboard: Most of your Telex: 650215-5052 MCI articles will be scheduled and run his series with emphasis on his control MCIMAIL (electronic mail system) ID: 215-5052 system and the permeability-tuned FAX: 860-594-0259 (24-hour direct line) over the next several issues; a couple are still pending queries from me as oscillators (PTOs). Mark has also Officers of this writing. We compensate promised to document for us the design President: RODNEY STAFFORD, W6ROD authors at the rate of $50 per pub- of the front ends—the parts that 5155 Shadow Estates, San Jose, CA 95135 lished page or part thereof, on pub- change from band to band. Executive Vice President: DAVID SUMNER, K1ZZ lication. We would be delighted to Audio pioneer Bob Heil, K9EID, The purpose of QEX is to: receive your further submissions at contributes his analysis of high-fidelity 1) provide a medium for the exchange of ideas the address listed on page 1 and look audio reproduction as it pertains to and information among Amateur Radio experi- Amateur Radio. He discusses what forward to hearing from you. Accept- menters, hardware is necessary and how it should ance decisions are made by me with 2) document advanced technical work in the be adjusted for best results under a Amateur Radio field, and the able assistance of the ARRL variety of conditions. Like his extremely 3) support efforts to advance the state of the Technical Advisory (TA) staff. Most of Amateur Radio art. popular seminars on the subject, this these volunteers are top professionals All correspondence concerning QEX should be piece benefits from Bob’s engaging style. addressed to the American Radio Relay League, as well as radio amateurs. Our editor- Frequent QEX contributor Parker Cope, 225 Main Street, Newington, CT 06111 USA. ial criteria are well documented on W2GOM/7 explains class-B transistor Envelopes containing manuscripts and letters for our Web page (www.arrl.org/qex/) publication in QEX should be marked Editor, QEX. amplifiers and gives circuit examples for and are available through regular Both theoretical and practical technical articles audio applications. are welcomed. Manuscripts should be submitted mail for the asking. Jim Kocsis, WA9PYH, has been recei- on IBM or Mac format 3.5-inch diskette in word- We also welcome your letters, ving high-resolution photographic tele- processor format, if possible. We can redraw any inquiries, comments and sugges- metry (HRPT) WEFAX and other figures as long as their content is clear. Photos tions. Civil discussion is always well should be glossy, color or black-and-white prints signals in the S band and contributes his of at least the size they are to appear in QEX. received. Long-time readers know down-converter design. According to Further information for authors can be found on that this publication may be what- Jim, the frequency may be moved up- the Web at www.arrl.org/qex/ or by e-mail to ever you want to make it.