If Frank Mankiewicz has his way, National Public Radio could become National Private Radio. The Washington-based network, which provides news, public affairs and arts programming to 280 stations, has been targeted for deep cuts in federal funds. NPR has clawed back with a half-dozen revenue-raising projects intended to free it (by 1988) from dependence on government money.

When the budget cuts were announced 18 months ago, NPR president Frank Mankiewicz responded quickly: "We're prepared to enter into almost any profession...except the oldest one.

"Our funding is down from $14.5 million two years ago to $11.5 million this year, $10 million next year," says Mankiewicz. "We have to replace that money, and it's not easy. Five years from now, we hope to generate $20 million from underwriting and about $20 million from our other ventures, without changing our programming quality or emphasis."

NPR's battle plan:

A major underwriting campaign with corporations, foundations and individuals, spreading their credits across all programming (some critics call it advertising without a message).

Subleasing commercially excess time on the NPR/Weststar satellite with Western Union.

Forming a joint venture, INC Telecommunications, with the McLean-based National Information Utilities Corp. to transmit digital information to homes and businesses using Weststar and FM subcarriers.

The National Satellite Paging System, another cooperative venture, this one with USA-Mobile Communications Corp. of America. It will be the first paging system that allows subscribers to be reached anywhere in the country.

A new partnership with DataSpeed to develop a portable radio that will yield printouts of nonbroadcast information (stock quotations, sports scores, airline schedules).