AM DA Equipment Design and Fabrication:


MP&A has been building phasors for AM DA sites for several years now.  We started out rebuilding older phasors for re-use in new or upgraded site, and moved on from there to design, build and paint our own aluminum cabinets.  Our phasors are lightweight yet extremely sturdy, with easily-removable side panels and rear doors for easy parts access.  The quality of parts we use is high; in many cases we reach outside the conventional phasor parts suppliers to embrace industrial electronics parts, noted for their toughness and reliability.

Tuning Units:

MP&A does the same thing and followed the same path for ATUs as we did for phasors.  Our ATUs are strong, well-sealed, and reliable.  We use conservative deratings for all coils and capacitors, to ensure long life and good service.

Site Controllers:

After many years of designing relay-based one-off phasor and site controller, MP&A has developed a PLC-based site controller, with a touch-screen GUI and extreme built-in surge protection.  Our unit has dual redundant power supplies and even comes with an emergency control panel, in case the unthinkable happens the the PLC dies (hasn't happened yet).  The site controller handles all transmitter power level control and monitoring, all interlock control and contactor timing issues, and monitors all tallyback indicators from the RF contactors in an array to prevent operation into a partially-switched array.  See the details here.


MP&A has been involved in AM antenna broadbanding research for three decades. Along the way we have developed measurement and computer analysis techniques that are second to none. We have designed and installed many broadband non-directional antenna tuning units, from 250W to 50 KW. All our phasors and ATUs are designed for maximum pattern and VSWR bandwidth and for IBOC compatibility.We have also rebuilt many directional antenna phasors and ATUs for greatly improved bandwidth compared to their original designs. As IBOC implementation approaches for more and more AM stations, it will become imperative for stations with narrowband phasors and/or ATUs-and that means most AMs that were built before 1980-to redesign their matching networks to be broadband. MP&A is ready with the software, test equipment, and expertise to resolve your broadbanding issues. We can rebuild your existing phasor or ATU in situ for maximum bandwidth, or we can design and build ATUs for your unique requirements in our shop.