ARRL Technical Information Service Merit Badge/Science Fair Projects File: scifair.txt Updated: February 26, 1999 Original text compiled by the ARRL TIS Staff Copyright 1999 by the American Radio Relay League, Inc. All rights reserved. Prepared as a membership service by the American Radio Relay League, Inc., Technical Information Service. For your convenience, you may reproduce this information, electronically or on paper, and distribute it to anyone who needs it, provided that you reproduce it in its entirety and do so free of charge. Please note that you must reproduce the information as it appears in the original, including the League's copyright notice. If you have any questions concerning the reproduction or distribution of this material, please contact TIS, American Radio Relay League, 225 Main St., Newington, CT 06111 (email: tis@arrl.org). ----------------------------------------------------------- The following is a list of projects that can be used for scouting merit badges or science fairs. The projects are designated with degrees of difficulty. Beginner - requires minimal or no soldering and has few components. Moderate - greater number of parts, some soldering skill and greater attention to detail required but still a good "first project" with some supervision. Advanced - recommended for someone who has built a project of this nature before. Kits are available, but instructions assume some knowledge. Some of the projects are from the pages of our publications and some are from commercial manufacturers. These projects can also be used as part of a larger "History of Morse Code", "History of Radio", or "How Radio Works" presentation. ----------------------------------------------------------- Code-Practice Oscillator (beginner) ARRL Now You're Talking Pg. 11-8 This is a complete oscillator that mounts on a small piece of wood. The circuit board for this project can be ordered from FAR Circuits. A complete parts kit, including circuit board, is available from the Hoosier Lakes Amateur Radio Club. Reprint of plans, instructions and parts sources available FREE to Students, Scouts and youth organizations; $3 to ARRL Members; $5 to Non-Members from: Technical Department Secretary, ARRL, 225 Main Street, Newington, CT 06111. FAR Circuits 18N640 Field Court Dundee, IL 60118-9269 USA Phone: 847-836-9148 (Voice mail) Fax: 847-836-9148 (same as voice mail) Web Site: http://www.cl.ais.net/farcir/ Ramsey Kits Hoosier Lakes Amateur Radio Club PO Box 981 Warsaw, IN 46581-0981 ----------------------------------------------------------- Ramsey Kits Crystal Radio Set - $19.95 (beginner) The Crystal Radio Set needs no batteries or reliance on modern semiconductor devices. You'll build a set similar to the ones built by early radio pioneers, using parts that are considered crude by today's standards. What a thrill to pull signals out of the air on such a simple radio. The detector uses an actual piece of Galena. The manual encourages experimentation with other detectors, even a pencil lead or an old razor blade, similar to the "fox-hole" radios of World War 2. Requires no soldering. Tunable FM Stereo Transmitter - $34.95 (moderate) Just connect a cassette deck or CD player and you're on-the-air with a school, dorm, camp, home, church or neighborhood FM station. Can be received with any FM receiver. No FCC License required. AM Transmitter - $29.95 (moderate) Operates in the standard AM broadcast band and is easily tunable to any clear spot on the dial in your area. No FCC License required. TV Transmitter - $27.95 (moderate) Allows you to send any audio and video source (like a VCR or TV camera (cam-corder) to any TV set for up to 300 feet. Tunable to any channel from 2 to 6. (To use this item, you will have to remove the Cable from your TV and set it to use an antenna - usually a switch in the back.) FM Broadcast Band Receiver - $24.95 (moderate) Receives standard FM broadcast as well as a large portion on either side. Aircraft Receiver - $29.95 (moderate) Tune into the exciting world of aviation. Listen to the airlines, business, private pilots, military pilots and control towers. (Recommended only if you are within 50 miles of a large airport.) Shortwave Receiver - $29.95 (moderate) Tune in the BBC, Radio Moscow, etc. True superhet design with AGC, RF gain control and plenty of speaker volume. 4 to 11 MHz frequency range. Ramsey Electronics, Inc 793 Canning Pkwy Victor, NY 14564 USA Phone: 716-924-4560 Fax: 716-924-4555 ----------------------------------------------------------- MFJ The MFJ-8100 Shortwave Regenerative Receiver Kit - $59.95 (moderate) This is a fine, attractive regenerative receiver kit that will stand up to the best of them. The regenerative receiver was the intermediary between the crystal and superhetrodyne in the evolution of radio. MFJ Enterprises PO Box 494 Mississippi State, MS 39762 USA Phone: 800-647-1800 601-323-0549 (Tech) Fax: 601-323-6551 Email: mfj@mfjenterprises.com Web Site: http://www.mfjenterprises.com/ ----------------------------------------------------------- Ten-Tec T-kit Model no. 1253 9 Band Shortwave Regenerative Receiver Kit - $59.00 (moderate) The classic "first radio kit" is back better than ever! We've combined the very same audio output circuit of Ten-Tec transceivers with a modern FET design for classic regenerative SWL receiving plus one-button electronic band switching. The result is an easy-to-build shortwave radio that's fun and interesting for the whole family. No alignment required! Simply install all parts as directed, put together the high quality mechanical parts and start enjoying the magic of shortwave radio. Explore 9 smooth tuning SWL and ham bands from 1.8 to 22 MHz at the push of a button! Receives AM, SSB, CW and all those other shortwave sounds. T-KIT No. 1054, Regenerative 4-Band SWL Receiver Kit - $24.00 (moderate) Suggested Enclosure-Plus Pak, No. 1000B, $19.50 This great little receiver is excellent for clubs, classes and family activities. Band coverage: 49 Meter SWL band, 40 Meter ham band, 31 Meter SWL band, plus exciting 12-15 MHz tuning for daytime shortwave listening, 20 Meter ham band and all those other magical shortwave sounds. The sharp-looking front panel gives the "real radio" look right away: dress up your project later with a case and knobs, and perhaps a speaker. You can enjoy the basic kit just by hooking up 9 to 12 volts DC, setting up a modest wire antenna (10 feet or more of hookup wire) and plugging in your own stereo headphones (1/8" plug). Features convenient push- button bandswitching, on-off switch, "on" LED, tuning, volume, regeneration control. Ten-Tec, Inc 1185 Dolly Parton Parkway Sevierville, TN 37862 USA Phone: 423-453-7172 423-428-0364 (Repairs) Fax: 423-428-4483 Web Site: http://www.tentec.com/ ----------------------------------------------------------- Homebrew (scratch built) The MRX-40 Mini Receiver (advanced) - QST September 1997, Pg. 59 A tiny 40 meter amateur band Morse code receiver barely larger than a half dollar. The Crystal Radio (advanced) - QST December 1997 Pg. 56 The simple crystal receiver described in this article works surprisingly well. Demonstrate a radio that has no obvious power source whatsoever! The Neophyte Receiver (advanced) - QST February 1988 Pg. 14 A simple 80 or 40 meter amateur band AM, Morse Code (CW) and Single Side Band (SSB) receiver. Reprint of plans, instructions and parts sources available FREE to Students, Scouts and youth organizations; $3 to ARRL Members; $5 to Non-Members from: Technical Department Secretary ARRL 225 Main Street Newington, CT 06111 USA