In an effort to freshen its image and lift revenue, the Public Broadcasting Service is trying to be more like HBO — without the monthly cable bill.

Emboldened by the success of the British period drama “Downton Abbey,” one of the most critically acclaimed shows on television, PBS now faces the challenge of translating the buzz and enthusiasm for the show into donations to local stations and public financing. A stodgy pledge drive or traditional pleas for contributions would probably fall flat with viewers. So, PBS decided to fit “Downton Abbey,” which begins its second season on Sunday, into a broader effort to spruce up its prime-time lineup.

The goal is to attract new viewers to PBS and make audiences think of public television more like the top-tier programming of HBO, Showtime and other channels they are willing to pay for. “Think of PBS and the local stations as premium television on the honors system,” said John Wilson, senior vice president and chief television programming executive at PBS.

Around the time the first season of “Downton Abbey” had its premiere on the “Masterpiece” anthology series last January, PBS began taking a more strategic approach to programming. It has branded nights with clusters of shows about one subject — for example, the arts, science or the literary imports from “Masterpiece.” The anthology introduced younger and more male-skewing shows like “Sherlock,” a mystery series set in modern-day London that had its premiere in 2010, and a continuation of the popular British series “Upstairs, Downstairs.”