WQVR(AM) 940 in Webster, Mass., has been granted a license to cover for nighttime operation of its High-Efficiency Broadband Antenna, or HEBA.
It’s a win for WQVR’s engineering team, which includes the HEBA’s architect, Phasetek’s Kurt Gorman, Isotrope’s David Maxson, Remote Media Service’s John Garrett and Loud & Clean Broadcast Science’s Grady Moates. WQVR’s HEBA is a compact AM broadcast antenna that occupies a 40-foot-square footprint and does not use ground radials or guy wires.
The station has been operating the HEBA under a non-directional daytime license at 1 kW since 2018. It now runs four watts at night. Nighttime operation began under a construction permit granted in April.
According to Moates, the catalyst in gaining the nighttime license was proving that the antenna would not cause skywave interference to co-channel CFNV(AM) 940 in Montreal. The U.S.-Canadian AM interference agreement requires WQVR to protect CFNV’s 0.5 mV/m skywave contour at the Canadian border. Moates said there have been no complaints from CFNV since WQVR began using the HEBA at night.
He said a consultant’s study submitted to the commission by Isotrope showed the HEBA skywave radiation at the CFNV departure angle will be reduced compared to the previously licensed monopole.
Isotrope’s study also cited the HEBA’s immunity to seasonal variations in ground conductivity due to its design. It said the antenna’s vertical pattern can be more precisely predicted by the modeling software used to submit for nighttime authorization to the commission.
So, how has the HEBA performed overall?
Well, Moates says listeners have reported that, while its signal does not reach farther than the monopole antenna it replaced, the signal within the expected, local groundwave coverage area has been more stable and less susceptible to power and utility cable interference. As more HEBAs are built, he expects to perform more experiments to prove these anecdotal observations.
It’s part of a greater business plan, says Moates, to expand availability of the HEBA. He said WorldWide Antenna Systems has been receiving many inquiries from in and outside the U.S.
[Related: “WQVR(AM) Is Granted CP to Use HEBA at Night“]
