NFL on Fox highlights UHF shortcomings; analog transmitter technology at its limits; stations turn to elliptical polarization for help. (National Football League)

Analog transmitter technology at its limits,' stations turn to elliptical polarization for help

With UHF frequencies now carrying a new load of highpriced NFL programing, at least one antenna seller is banking on the noisy transmissions to sell more equipment to frustrated football fans.

The company---Radio Shack---will not have to worry about transmitter makers undermining the campaign. Those analog UHF signals, broadcast engineers say, are about as good as they are going to get.

And although digital technology promises to clean up UHF pictures once an advanced television standard is set, displaced network affiliates and UHF station viewers in the …