There’s good news for Valcom, and it’s a development that will be of interest to AM stations that want to build or move towers.
The FCC has adopted simplified application procedures for certain Valcom antennas.
The Valcom is only approved for non-DA use; the Media Bureau will consider authorizing its use in directional arrays when it has more information.
Based on its review of Valcom field test results, the Media Bureau will no longer routinely require performance proofs to be submitted, nor current distribution measurements, nor a formula for the vertical plane radiation characteristic for non-DA facilities that use Valcom antennas.
The Valcom 75-and 85-foot Coil Loaded, self-supporting whip antennas are shorter and more streamlined than the one-quarter wavelength lattice tower typically used by AMs, according to the commission.
The FCC has approved two Valcom models for use by AMs at higher frequencies: the 85-foot antenna can be used from 1200 to 1700 kHz and the 75-foot model can be used from 1390 to 1700 kHz. Submitted tests results show the calculated efficiencies of both antennas, which meet or exceed the minimum efficiency for Class B, C and D AM stations, the commission said.
“The field tests on which the calculated efficiency figures are based were performed with the Valcom antenna mounted above a ground system consisting of 120 buried radials, each 120 feet in length,” stated the FCC in its notice. Applicants who want to use these particular Valcom antennae for non-DA use must use those same antenna efficiency values.
The FCC said the low-profile Valcom gives AM licensees flexibility to locate antennas in places where taller towers would be unacceptable, and be more economical to build and maintain than a standard antenna.
Engineering observers say having the Valcom as a choice will make it easier to build and re-locate certain AM transmitter sites on less expensive land plots closer to intended service areas.
