Introduction

A glowing 304TL in a homebrew rig by Bill - KD0HG.

From vintage tube-based gear, to military surplus, to modern, ultra-efficient FET-based Class E transmitters, Amplitude Modulation (AM) offers the experimenter, homebrewer, and radio restoration buff great opportunities to learn, build, and enjoy radio. AM was once the main voice mode in amateur radio. Now it is a well regarded specialty within the hobby. AM offers a warm, rich audio quality that provides for more personal interaction. The simplicity of AM circuit design encourages hands-on restoration, modification and homebrew construction to an extent no longer found among contemporary radios.

Looking for AM activity? Check here.

This web page was created and is maintained by Steve Ickes, WB3HUZ. You may contact the author directly at steve@amwindow.org about the page or its contents. ARRL extends its thanks to the volunteers that help make ARRL's web pages a useful resource for all.

Want to operate the vintage AM station at W1AW?

AM Station Information

W1AW guest operation schedule  

Articles

Note: Some of the following articles are in Adobe Portable Document Format (PDF) files. To view and print these files, you'll need a copy of Adobe's Acrobat Reader program. (Version 4.0 or later required). More information here.

• Classic Rigs and Amplitude Modulation: Friendly, Nostalgic Ham Radio Partners. (896,270 bytes, PDF file)
  QST February 1993, pp. 43
  An introduction to current day AM activities within Amateur Radio.
  
  
• Some Principles of Radiotelephony.
  QST 1954;
  
  May (505,258 bytes, PDF file)
  June (380,522 bytes, PDF file)
  July (730,100 bytes, PDF file)
  October (507,820 bytes, PDF file)
  The basics of AM in four easy parts.
  
  
• A Course in Radio Fundamentals, Part 6 -- Modulation (1,030,966 bytes, PDF file)
  QST November, 1942, p. 53
  Another good AM primer.
  
  
• Introducing: The AM Radio Network (91,828 bytes, PDF file)
  QST December 1995, pp. 46
  More on current day AM operation.
  
  
• Hams Redeem Old Transmitter at Fountain of Youth (475,272 bytes, PDF file)
  QST November 2003, pp. 56
  The story of a rescue and Restoration of a Collins 300G Broadcast Transmitter
  
  
• Audio Preamp with AGC and Feedback to Improve AM Fidelity (66,541 bytes, PDF file)
  QST November 1997, pp. 36
  A sweet little mic preamp that also helps control modulation levels.
  
  
• Constant-Carrier AM for the Drake Twins (Hints and Kinks) (244,295 bytes, PDF file)
  QST November 1994, pp. 85
  Make these venerable radios sound much better.

  One corner of the KW1I shack with a TCM-2 in the center. It is a World War II Navy transmitter, 2-18 MHz, CW, MCW and voice.

  
  
  
• Technical Topics - Some Facts on Modulation (412,711 bytes, PDF file)
  QST March 1951, pp. 49-51, 116.
  An excellent explanation of how AM works. A good read for beginners and old-timers alike.
  
  
• Technical Topics - Linear Amplifiers for AM (318,414 bytes, PDF file)
  QST Feb 1956, pp. 39-41
  There's more than one way to generate AM. Get the scoop on using a linear.
  
  
• Radiotelephone Transmission (812,476 bytes, PDF file)
  ARRL Handbook, 1929, pp. 98-107
  See how AM was done in the early days.
  
  
• Lop Sided Speech and Modulation (1,064,137 bytes, PDF file)
  QST February, 1940, p.14
  Get the straight dope on speech asymmetry and its application to AM.
  
  
• Three Control Six-Band 813 Transmitter
  • QST, Jan 1954, pp. 11-16, 112, 114, 116 (1,087,092 bytes, PDF file)
  • QST, Jun 1954, pp. 37-39, 118 (475,128 bytes, PDF file)
  • QST October 1956, pp. 33-38 (626,007 bytes, PDF file)
  • ARRL Handbook 1957, pp.192-197 (720,163 bytes, PDF file)
  This transmitter was all the rage in its day and would be the envy of many AMers today.

  The beautiful vintage station of Bill - WR0T, flush with some classic Collins and Drake Equipment.

  
  
  
• The Ultra Modulation System Using Higher Audio Power Without Splatter (289,760 bytes, PDF file)
  QST, October 1956, pp. 27-29
  Shows how to increase modulation peaks for more effectiveness.
  
  
• An AM/CW Exciter for 144 Mc. (657,027 bytes, PDF file)
  QST September 1965, pp. 39
  Try some local contacts without the repeater.
  
  
• Synchronous Detection of AM Signals (903,534 bytes, PDF file)
  QEX September 1992, pp. 9
  Feedback:
  Nov. 1992 p. 21 (260,615 bytes, PDF file)
  Dec. 1992 p. 15 (237,334 bytes, PDF file)
  A great primer on sync detection and the advantages of using it for AM signals.
  
  
• A Simple Synchronous-AM Demodulator and Complete Schematics for the DDC-Based Receiver (173,349 bytes, PDF file)
  QEX September 1997, pp. 3
  
  
• A Synchronous Detector for AM Transmissions (484,962 bytes, PDF file)
  QST July 1993, pp. 28
  Build a sync detector for yourself.
  
  
• Synchronous AM Detectors (95,457 bytes, PDF file)
  QST September 1992, pp. 65
  
  
• The 6LE8 One Tube Transmitter
  This one-tube transmitter is designed for the AM broadcast band, but it can be easily modified to do AM on 160 meters.
  

Notes:

Contact information for suppliers mentioned in the above articles should first be confirmed using TIS Address Database Search.

Bibliography (Members Only)

ARRL Periodicals Index Search - This database contains the QST index from 1915 to the present and the QEX index from 1981 to the present. For QST issues from 1970 to the present, and some selected articles back to 1922 (when construction articles featuring tubes began in earnest), identifying keywords have been added to the technical articles. By entering keywords (ANTENNA) or combinations of keywords (CONSTRUCTION ANTENNA VERTICAL HF) into the Title words: field, you may create dynamic bibliographies.
Technical article KEYWORD list. Hints for more successful searching

Web Links:

• The AM Window
  This web site, previously featured in the Surfing' column, contains extensive coverage of AM topics, including information on construction and modifications, AM operating events and social gatherings, AM Nets worldwide, audio and visual coverage of AM stations and operators, and much more.
  
  
• AM Fone.net
  A vast storehouse of AM information and regional coverage of AM operators and activity. This site also feature a bulletin board for quick and easy access to AMers around the globe and their radio knowledge.

  A solid state Class E RF Amp by Tom - K1JJ.

  
  
  
• The Official Class E Transmitter Web Site
  The goal of this site is to present a working, practical tutorial on class E transmitters (a complete explanation of class E is included), and to provide sufficient information to allow someone with reasonable radio experience, technical skills and knowledge to construct a working class E transmitter or design a transmitter using similar RF and modulation methods.
  
  
• Class E Forum
  This forum is for technical support and general questions about building and operating Class E-AM transmitters. Tap into the experts' knowledge!
  
  
• Electric Radio
  A monthly publication covering the vintage and AM aspects of Amateur Radio.
  
  
• Synchronous Detection of DSB and ISB Signals
  A Synchronous Detector designed with the use of an LM311 and an Analog Devices AD607 by Pete, WA1SOV
  
  
• Broadcast Transmitters on the Ham Bands
  Hams Give Second Life to Legendary Transmitters With Names Like RCA, Collins, Gates and Raytheon.
  
  
• AM Forever
  For ham radio operators and shortwave listeners interested in learning and preserving the practice of receiving and transmitting amplitude modulation.
  
  
• Boat Anchor Manuals Archive - BAMA
  This archive has manuals for every major radio manufacturer and quite a few minor ones.
  
  
• Searchable Tube Database
  Enter a tube type and get pinout, characteristic and sub data. Close to 3000 types including transmitting and receiving.
  
  
• Tube Data Sheet Locator
  A database search engine which contains links to valve/tube data on the web.It also contains short form data and pinout information on many valves, and a list of substitutes.
  
  
• Live Audio Stream of 3885 kHz AM
  Listen to the AM action while you surf the Web.
  
  
• The Southeastern AM Radio Club
  AM Radio in the Heart of Dixie.
  
  
• AF4K / G3XLQ's Ham Radio Files
  Hundreds of links to tube and vintage radio info, parts and projects
  
  
• Frank's Electron tube Pages
  Tube data sheets for almost 10,000 different types, including European and Russian types.

Article Reprints:

You can get a photocopy of any ARRL published article for $3 ($5 for nonmembers) for each article requested. Contact the ARRL Technical Department (reprints@arrl.org ), 1-860-594-0390) if you wish to get photocopies.

This information was prepared as a membership service by the American Radio Relay League, Inc., Technical Information Service, 225 Main St., Newington, CT 06111 (860) 594-0214. Email: tis@arrl.org (Internet). ARRL HQ is glad to provide this information on the Web free of charge as a service to League members and affiliated clubs.

If you have any questions concerning the reproduction or distribution of this material, please contact:

TIS Coordinator
American Radio Relay League
225 Main St., Newington, CT 06111
Tel: 860-594-0214 Fax: 860-594-0259
(email: tis@arrl.org)