AM Broadcast - New Beginnings
AM radio broadcast, the original RF broadcast medium, may not be in its heyday any longer but it is still live and well and operating between 530 kHz and 1705 kHz.
Once known as the only source to "watch" for late breaking news coverage, live sports, music and theater, the medium now captures only 20 percent of the total radio listening audience. FM radio offering improved fidelity and less noise, now holds the remaining 80 percent of the listeners. The conversion of the listening audience from AM to FM took place over 20 short years between the 1960's and 70's.
When listeners migrated to the FM broadcast format, so did the radio manufacturers, supplying improved FM receivers and tuners while at the same time neglecting any further improvements to the AM sections within the same radios. Not only did AM circuitry in broadcast radios stop advancing, but in most instances manufacturers actually downgraded the AM section of their radios for the sake of cost savings.
Today, your typical AM or AM/FM receiver, whether for car or for home will not have the same quality of AM fidelity, sensitivity, or selectivity that could be found in similar receivers built before the mid 1960's.
Recognizing problems within their own industry in the 1980's, broadcasters through their association with NAB - National Association of Broadcasters, looked for solutions to create a greater listener demand for AM radio. One of their first options with FCC approval, was to expand the AM band to 1705 kHz, and the next step was to introduce AM stereo. The concept of AM stereo was nice, except there were few takers to this new enhancement. Two very different and competitive stereo encoding systems were developed in the mid 1980's by technology developers Khan and Motorola. They both fought hard for industry dominance, but neither one could truly lead the industry to a single standard. The two fought it out for ten years before Motorola with greater resources finally set the pace with their C-Quam stereo standard with DAB technology right on their heals.
To fill the disparity between AM stereo, future in-band DAB technology and other emerging technologies, AM broadcasters and receiver manufacturers got together in the 1980's to form a new broadcast standard called AMAX or AM at it MAXium. The AMAX solution actually sets our AM broadcast listening standards back approximately 35 years, yet commits to the use of high technology.
AMAX is a certification program developed by the National Association of Broadcasters and the Electronic Industries Associates to help set minimum performance standards for the manufacture of AM broadcast receivers. To become certified, the qualified piece of receiving equipment must meet six quality standards for reception, and operating control features, including adjustable bandwidth, stereo ability, and connections for an external antenna. When built into a receiver, these quality standards ensure that the AM signal received is as good as the AM signal being broadcast.
In keeping to the goals set down by AMAX standards, the progress of in-band DAB or Digital AM Broadcast technology has moved forward in recent years to develop an absolute flawless digital sound - but even today before this "in-band" digital technology can be fully accepted, it may simply be by-passed like a distracting tangent by yet even newer digital broadcast technologies and standards operating "out of band" in the upper UHF and microwave regions. But regardless of changes in technology, to the devoted, the noisy and skip prone spectrum between 530 kHz and 1705 kHz will always remain a sacred area called the AM broadcast band.
If AMAX certified equipment is going to be your next choice for improved AM listening, or you just want to dust off the old wooden boxed AM receiver, then the LF Engineering M-601C is the natural choice for your AM active antenna needs. Easy to install and operate for fixed station or portable operation. No variable matching tuners, long wires, loading coils or whips are used. The M-601 AM BC active antenna is based on the proven L-400B VLF design and operates as a powered fixed tuned omnidirectional E-field probe providing high gain, low noise full bandwidth AM reception.