The shutdown of U.S. analog TV service on Friday appears to have gone relatively smoothly, but as expected, a lot of viewers are having problems getting the stations they want.

The problems have ensnared even the technologically sophisticated.

Wally Grotophorst in Hamilton, Va., got a “digital” antenna for his digital TV last year. But on Friday, he lost the Washington-based ABC and CBS stations, channels 7 and 9, which he could pick up digitally before the transition.

That’s because those stations, like dozens of others, switched their digital signals from the UHF frequency band to the VHF band as they cut their analog signals Friday. But Grotophorst’s antenna, like many others branded as “digital” and sold over the past few years, was designed only for UHF stations. Nearly all TV stations were using the UHF band for the digital broadcasts until Friday.

“This moving down to the VHF spectrum was news. The stations didn’t advertise the fact,” Grotophorst said.

He’s now regretting that he recycled his old rooftop VHF antenna.

“The station did warn viewers about this change but not everyone got the word,” said Bill Lord, vice president of news at ABC7. “The station has made the switch and there is no going back.”

There are TV antennas that can receive both UHF and VHF bands. In the indoor version, these have long extendable poles – the “rabbit ears” – for VHF reception and a loop for UHF.

Brett Whitten, a technology consultant in Philadelphia, lost the ABC-affiliated Channel 6 for the same reason. He was unsuccessful in attempts to improvise a VHF antenna out of wire, helped by instructions he found online.

According to a Monday evening newscast, that station was talking to the Federal Communications Commission to see if it could increase its output power. That could help with reception, at least for those who have VHF antennas.

The FCC said it is examining reports of signal loss by viewers of some stations in Chicago, Philadelphia and New York.

The FCC said more than 20 percent of the 317,450 callers to its help line on Friday had problems receiving at least one station, making it the most frequent problem after converter-box setup and requests for converter-box coupons.

Those converter boxes allow older, analog sets to view digital signals after Friday’s cutoff, following years of planning, of the transmission technology in use since the days of Milton Berle and Howdy Doody. The digital signals are more efficient, freeing up airwaves for cell phones and other services.

If a station is missing, viewers should first try to force the converter box or digital TV to “rescan” the airwaves for channels that moved to new frequencies on Friday.

For those who aren’t helped by that, the FCC put out a new advisory Monday recommending “double rescanning.” That involves disconnecting the antenna from the box or TV, rescanning, turning off the box or TV, then turning it back on, connecting the antenna and scanning one more time. The procedure can clear the box or TV’s memory of saved channel information that is now incorrect, the commission said.

All full-power stations have now shut down their analog signals. Some low-power stations and rural relays known as “translators” are still broadcasting in analog.