There'll be an antique show and sale with more than 100 dealers at the D.C. Convention Center's Exhibition Hall C, 900 Ninth Street NW, Friday from noon to 9, Saturday from 11 to 9, and Sunday from 11 to 6. $3.50; 789-1600 . . . The Washington Ringing Society conducts a one-hour demonstration on bellringing Saturday at 10 a.m. at the Old Post Office Tower, Pennsylvania Avenue and 12th Street NW; 523-5691; free . . . The Columbia Historical Society at 1307 New Hampshire Avenue NW sponsors a bus tour of historic houses of worship in 19th-century D.C., Sunday from 1 to 5:30. $12, $15 for nonmembers; Call 785- 2068 for reservations . . . Pianist Lydia Artymiw performs Sunday at 7 in the Grand Salon of the Renwick Gallery of the National Museum of American Art, the first concert in the Pro Musicis Series, a program sponsored by the Smithsonian Resident Associates, and featuring rising young talent. $10, $5 for students; 357-3030. IN MARYLAND

The University of Maryland's sixth annual Tudor Feast is Friday and Saturday at 7 p.m. at the Stamp Union Grand Ballroom, and includes a five-course meal, madrigals, instrumentalists and dancers; $22 each night; 454-2803 . . . Singer/songwriter David Alan Gates performs a rock concert Saturday at Eleanor Roosevelt High School, 7601 Hanover Parkway in Greenbelt. Ticket proceeds go to Students Against Drunk Driving of Prince Georges County; $3; 322- 2857.