A Texas television reporter jailed for refusing to reveal sources said yesterday he has no plans to break his promise to withhold names of those who helped him interview a prisoner last year.

In a telephone interview from jail, where he has served one week of a six-month term, Brian Karem, 29, a reporter with NBC affiliate KMOL-TV in San Antonio, cited the constitutional amendment protecting freedom of the press and said he would continue to withhold the names. Most journalists believe that a promise to protect a source is sacrosanct.

"I'm prepared for six months in here, but I don't want to be in here," Karem said from the Bexar County Adult Detention Center in downtown San Antonio. "I have a wife and child I want to see. But I gave a promise, and I believe that promise must be kept under the First Amendment. I won't be intimidated by a court of law or a prosecutor or any attorney."

Karem last year interviewed Henry David Hernandez, who is accused with his brother Julian in the shooting death of a police officer in San Antonio. On the telephone, Hernandez told Karem he shot the officer in self-defense, that his lawyer had told him not to speak to the media and that his brother was not involved. Karem later broadcast a tape of the interview.

Karem has said those who helped him obtain the interview asked for anonymity. So far he has defied three court orders to turn over his notes.

The Hernandez case is scheduled to go to trial in November, and both prosecutors and defense attorneys want the names of Karem's sources to determine whether the tape aired on KMOL news can be used as testimony. The lawyer for Hernandez does not want the interview admitted as evidence. The lawyer for his brother does.

The attorneys say they need to know Karem's sources to determine whether law enforcement officials may have been trying to bypass the legal system by getting a talkative Hernandez to confess on the record without his lawyer, or whether the policeman and the two accused of the killing knew each other in advance of the shooting.

In February, State District Judge Pat Priest held Karem in contempt of court, and an appeal to U.S. District court brought another ruling last month that Karem must surrender the notes. The Supreme Court denied an appeal for a stay of Karem's jail sentence while it considers the underlying issues.

Karem said yesterday that guards have treated him "fairly" while he waits for his lawyer to continue his appeals. "I think it's a very important issue," he said. "All you have in this business is your credibility. If people can't believe you, if we don't keep our word, we'll be in trouble in this country."