IN MY HEAD THERE'S a wire service machine, a news ticker, as we call them -- one of those clackety-clackety things you hear at the start of the Cronkite show. News organizations have them, of course, and so do some rich people who keep them in closets, but i've got one in my head that goes off sometimes when I read something in the paper. It happened the other day when the Senate went into secret session to discuss charges that the brother of Panama's president was involved in the drug racket. I heard it coming. Clackety, clackety . . .

PANAMA CITY -- The Panama Senate went into unprecedented secret session today to discuss allegations concerning the family of American President Jimmy Carter, particularly, sources said, reports that Carter's brother, Billy, has been linked to a beer company.

The session was called after opponents of the canal treaty said that they also had secret information that Billy Carter had on occasion dressed up in a suit of armor made from the pop-tops of beer cans.

"As ridiculous as it sounds, that is the information we get," said Sen. Raymond Lopez Garcia (D-Colon), the wily head of the foreign relations committee. "Here we are being asked to give American warships head-of-the-line privileges when the President's brother dresses up in pop-tops, whatever they are," the Colon conservative said.

Reports also circulated here that Billy Carter had allowed his name to be used on a brand of beer and that he has appeared at carnivals, state fairs and on television, dressed in all kinds of weird costumes and often drinking beer. In fact, one of the allegations reportedly being discussed in the secret session is that the U.S. president's brother will do anything for money.

The questions raised about President Carter's family comes at a particularly critical time in the debate over the canal treaty. A small group of conservative senators, claiming they have enough votes to deny the pact the three-quarter margin it needs for ratification, argue that the United States should be forced to maintain and operate the canal. "They built it, they operated it, they own it," argued Garcia. "It's 75 years old and no bargain now. Why are they trying to get rid of it?"

Treaty opponents have launched a well financed advertising campaign using Reynolds Oregano, a former Latin American film star, as a chief attraction. Oregano, a feisty 87 years old, said in a nationwide television speech that in addition to Billy Carter, Mr. Carter has one sister who is a fundamentalist preacher and another who rides around on a motorcycle dressed in butterfly pants. Warming to his subject, Oregano said that another member of the president's family had a worm farm and that the president's very own mother had joined the Peace Corps at the age of 62 and gone to India. He said most Americans that age go to Florida.

The attempt by treaty opponents to ling Mr. Carter to his family was a most unexpected development here. The American Embassy, which has yet to comment on the debate, was reliably reported to be studying a three-page report issued earlier in the week by White House Press Secretary Jody Powell. One source there said the report must be related to the treaty question because no other explanation is possible.

Meanwhile, the Panama City Daily El Otro Periodico, escalated what is called here "the brother's debate" (e debato brothero) by noting that American presidents have a history of trouble with their brothers and that this is likely to continue. The paper said that Richard Nixon's brother was linked to Howard Hughes who was linked to everyone. Donald Nixon, the paper reported, borrowed money from Hughes to open a hamburger business in California and became the first person in the history of California to go broke in the hamburger business.

The story also revealed that former president Johnson had a brother named Sam who was almost never heard from and Gerald Ford's brother was not his brother since the former had been adopted. Everyone agreed that this tended to complicate matters and people were seen walking away from the newspaper offices saying, "this complicates matters."

The whole question of whether a national leader should be held accountable for a relative is under debate here. It is generally conceded that men are not responsible for their wives or for their children, some of whom smoke pot, or, as Susan Ford did, appear on Laugh In. Brothers and sisters, however, are a different story since they may know of something that the head of state did when he was just a kid and can still threaten to tell the parents. This is he shoe that never drops . . .

With that, my news ticker stops and I hurry off to call my parents. There's something I've been meaning to tell them before my sister did.

I was the one who broke the lamp.