AM HANDBOOK
Operating AM on amateur radio has many challenges over and above other modes of operation. There are basic elements that need to be understood an mastered in order to operate a high fidelity, fully modulated, legal limit AM station. Careful attention needs to be given to carrier power levels, percent of audio modulation, frequency response, bandwidth use and signal quality all in order to produce a high fidelity AM signal. An AM operator needs to clearly understand these elements, how to control them and how they affect bandwidth use. Most importantly any amateur radio operator needs to know how wide their transmitted signal is and be considerate of other while transmitting in any mode.
This AM Handbook is designed to be a basic guide to the elements of operating an AM station. The guidelines found here are intended to be a starting point that can be expanded on
AM BASICS
The goal that all good sounding AM operators work to achieve is a fully modulated carrier. Reaching 100% positive peaks without passing 100% negative peaks allows as much audio as possible with creating distortion.
This AM Handbook is designed to be a basic guide to the elements of operating an AM station. The guidelines found here are intended to be a starting point that can be expanded on
AM BASICS
The goal that all good sounding AM operators work to achieve is a fully modulated carrier. Reaching 100% positive peaks without passing 100% negative peaks allows as much audio as possible with creating distortion.
Receiving and listening to AM - Things you must do!
The whole point to operating AM is the fidelity. The rich lows and the crisp highs bring a quality sound to any QSO that is an absolute pleasure to listen too. Just about any receiver is capable ot listening to an AM transmission so long as some basic steps are followed
Signal Width
Operating AM requires transmitting TWO side bands. This means that an AM transmission takes up twice as much space as a Single Sideband Signal (SSB). Understanding the relationship between carrier levels, audio modulation levels and frequency response is key to being a good AM operator
Frequency Response aka High Fidelity
Frequency Response is the number one thing that make AM sound so good. It is widely misunderstood and worse yet is widely abused by amateurs who seek to transmit that HiFi sound. Not every frequency can be heard by human ears or reproduced by all receivers, nor can every frequency be transmitted by all transmitters. Learn how frequency response impacts band width.
RF Power Levels - Carrier vs PEP
RF Power Levels - Carrier vs PEP AM transmissions like all modes on the amateur radio service have power output limits. Unlike other modes it is the combination of carrier power and modulation levels that ultimately make up the amount of power transmitted. Proper balance of carrier vs audio is key to having a good sounding bandwidth respectful AM station.
Antennas, Tuners and other Equipment Impact on AM
Antennas, Tuners and other Equipment Impact on AM When operating AM, the antenna is just as important as the microphone. Narrow high Q antennas and tuners can wreck an AM stations signal creating havoc in the shack. Here are some tips an tricks for best practices when operating AM.
What the FCC Says |
Tips and Tricks |