Directors of The National Bank of Washington have elected Dale L. Jernberg to the position of vice chairman of the board.

Jernberg began his banking career with the Liberty National Bank almost 23 years ago. After Liberty merged with The National Bank of Washington he rose to the head of the trust department in 1965. In 1973 he was named executive vice president and a director of the bank and later that year he became a member of the executive management team.

Weitzman and Associates advertising and public relations agency announced it has changed its name to Weitzman, Dym and Associates Inc. Diane S. Dym is executive vice president of the agency and has been with the firm since it was founded in 1970.

The board of directors of Amtrak has re-elected Donald P. Jacobs as chairman for another year Charles Luna was elected to a one-year term as vice chairman.

Jacobs, who is dean of the graduate school of management of Northwestern University, was named to the Amtrak board in 1974.

Luna was appointed to the board in 1971 and is a former president of the Brotherhood of Railroad of Trainmen and of the United Transportation Union.

Equitable Trust Co. has elected E. Neil Jacobs an executive vice president of the bank. Jacobs was formerly president of University National Bank, of Rockville, an affiliate of the Equitable Bancorporation, the holding company of which Equitable Trust is also an affiliate.

Jacobs will continue to serve as chief executive officer of University National as he coordinates the merger currently in progress of University into the Equitable Trust Co.

Jacobs has been in banking since 1963 and prior to joining University National, he was president of the Commerce Bank and Trust Co. of Bethesda.

John D. Cogswell has been elected vice president, corporate planning, and Randolph K. Hambrick was named vice president, district agencies administration, of Peoples Life Insurance Co.

Richard E. Dunkley Jr. has been named president of the Metropolitan Washington Association of Independent Insurance Agents. He also served as president in 1976-1977.