What was going on when I was born?

JONATHAN BELKIN'S house in Queens needed major repairs, including a new heating system, new kitchen and bathroom, electric wiring, windows and exterior siding. Like many consumers, he knew nothing about construction. He simply threw himself at the contractors' mercy, asking for the ''best price'' for the ''highest quality material and workmanship.'' Under these circumstances, Mr. Belkin might easily have become one of the four persons a day who complain to the New York City Department of Consumer Affairs about contractors who have abandoned projects, used poor materials or done shoddy work. ''Mr. Belkin,'' however, was a phony consumer, an undercover investigator for the department whose work requires him to remain anonymous. Following his investigation, charges were brought against four contractors for violating the city's home improvement regulations, and summonses were issued to seven unlicensed contractors and seven unlicensed salesmen that called for their appearances at departmental hearings or told them to apply for licenses.

Bullets ricocheted around the Amman Intercontinental during Jordan's 1970 civil war. Revolutionaries smashed windows at the Teheran Intercontinental while the Shah's regime was being overthrown. Sheiks have been sauntering through the Riyadh Intercontinental since well before the 1970's oil boom. History and revenues have been flowing copiously through the farflung portals of the Intercontinental Hotels Corporation, which is the most profitable subsidiary of ailing Pan American World Airways. It logged pretax earnings of $23.8 million on operating revenues of $136.7 million for this year's first half.

The United States said today that two Navy F-14 jets shot down two Soviet-built Libyan SU-22's about 60 miles from the Libyan coast after being fired on by one of the Libyan aircraft. The brief battle occurred in the final hours of a two-day United States Navy Transcript of Weinberger's remarks and text of U.S. protest, page A8. exercise in the southern Mediterranean and the northern part of the Gulf of Sidra, the United States said. It said the two Libyan fighters were downed by Sidewinder missiles fired by the F-14's in a one-minute dogfight over the Gulf, a broad body of water that Libya claims as part of its territorial waters but that the United States regards as international waters. Pentagon officials said the American planes returned to the carrier Nimitz safely. A Pentagon official said that the two Libyan pilots were seen parachuting but that one of the chutes was believed to be in flames.

''Under these conditions of operations such as this, that if an enemy aircraft conducts a hostile act, in this case did take on fire of our two aircraft, the aircraft flight commander has the authority to defend himself; in this case, that's exactly what he did.'' - Lieut. Gen. Philip J. Gast, director of operations of the Joint Chiefs of Staff. (A8:1.)

The economy contracted at a revised annual rate of 2.4 percent in the second quarter, more than previously estimated, after a robust 8.6 percent growth rate in the first quarter. Corporate profits also fell after a first-quarter rise, the Commerce Department reported, with after-tax profits down 11.3 percent to an annual rate of $150.1 billion. But economists declined to forecast a recession. (Page D1.) The MacArthur Foundation of Chicago is selling its vast assets in insurance companies and real estate to comply with Federal laws limiting business ownership by tax-free, private foundations. Experts said the sale might realize between $1 billion and $2 billion, consolidating the foundation's position as a leader in its field. (A1.)

A listing of airline profits in Business Day on Saturday incorrectly labeled the period covered. The results were for the second quarter of 1981.

The United States economy suffered an even sharper downswing during the second quarter than originally estimated, while corporate profits posted a steep decline, the Commerce Department reported today. The gross national product, the value of the nation's goods and services, is now calculated to have declined during the April-June period at an annual rate of 2.4 percent, adjusted for inflation, a somewhat faster pace than the 1.9 percent decline initially reported four weeks ago. Profits after taxes fell 11.3 percent, in part because of high interest rates, the report said. The new G.N.P. figure compared with an 8.6 percent rate of gain in the first quarter - a figure reached after two upward revisions.

A Federal investigation to see whether Bridgeport's Superintendent of Police would accept a bribe took an unexpected twist last night: the local police arrested an undercover operative as he passed the money. At dusk in a city parking lot, local officers and agents of the Federal Bureau of Investigation confronted each other - the F.B.I. demanding the release of its operative and the return of the money, the police refusing. In the end, the police arrested the operative, Thomas Marra Jr. of Bridgeport, and charged him with trying to bribe the Superintendent, Joseph A. Walsh. ''I've seen some Mickey Mouse operations in my time,'' said Inspector Anthony P. Fabrizi, Bridgeport's Chief of Detectives, ''but this takes the cake.''

Afghans decide to modify land program to gain support A3 Canadian press attacks plan to curb newspaper chains A4 3 blacks in South Africa sentenced to death for sabotage A6 I.R.A. hunger strike is issue in Ul- ster by-election A7 Text of U.S. protest to Libya A8 Transcript of news conference held by Weinberger and aide A8 Libya criticized U.S. maneuvers before air battle took place A11 U.S. officials to visit Bonn in Fall to plan energy cooperation A13 Israel stands on previous position for West Bank autonomy A15 Soviet delaying development of a new Siberian natural-gas field A17 Government/Politics City to open accounts again in mi- nority-owned banks B6 Barbaro and Esposito give views on travel in New York City B8 General Company closes in honor of Lech Walesa's stepfather A2 Hijackers return Iranian gunboat to France A3 Oil companies not concerned by possible Libyan crude cutoff A9 Around the Nation A18 Pennsylvania township forcing out Indian artifacts exhibit A18 Tropical storm Dennis heads to- ward Charleston A18 Four charged with selling techno- logical equipment to Soviet A19 Historians find evidence of a black Pilgrim at Plymouth A28 North Carolina county gets cus- tody of twins A32 Norwalk police grow beards as contract talks stretch out B2 Tug captain's charting of cruiser questioned at hearing B3 Defendants in attempted helicop- ter escape go on trial B4 Home Section Home No space, but ingenuity adds room for a child C1 City runs a scam on renovation deals C1 A four-poster binge: sleeping it off C8 Insured warranties for home buyers C11 Hers C2 Helpful Hardware C2 Handicapped youth in garden project C3 Home Beat C3 Home Improvement C4 Calendar of Events C5 Outlet stores offer bargains C7 Design Notebook C10 In Japan, three centuries of pot- tery tradition C12 Saving Bloomsbury set's Sussex haven C13 Health/Science Heart attack rate higher for long- term users of birth control pills A28 16 cases of legionnaires' disease found in Buffalo area in 1981 B2 Arts/Entertainment Jacob's Pillow Festival hails past, present and future C15 The question of gifts to arts critics is raised C15 Dissension in New York world of concert-program magazines C16 Mrs. Gray tells how her latest novel evolved C16 Nationwide premiere of "Annie" movie to benefit PBS C16 Jerry Herman's songs make up revue, "Jerry's Girls" C18 Harry Hurt 3d's study of the H.L. Hunt dynasty is reviewed C19 U.S. Terpsichore gives dance pro- gram in Damrosch Park C19 Corporation for Public Broad- casting choosing new president C21 ABC News visits a Trappist monastery in Massachusetts C31 Sports Ira Berkow on Frenchy Fuqua B14 Coe, in mile, and Nehemiah, in hurdles, set world marks B15 Marshall case shows baseball sal- ary extremes B15 Mets lose; Youngblood on 15-day disabled list, Marshall signs B15 John returns to rotation, but Yan- kees lose by 6-5 B15 Baseball officials revise playoff plan B17 News Analysis Frank Lynn on the issue of Dearie's income tax returns B6 Michael Quint discusses Reagan budget deficit outlook D1 Editorials/Letters/Op-Ed Editorials A30 Gulf of Sidra episode Reagan policies: no free lunch More prisons to contain crime? Letters A30 William Safire: the great capabil- ities of Britain and the U.S. A31 Carl T. Curtis: time to outlaw union violence A31 Benson Bobrick: New York City subways: a link with the past A31 John Rothchild: energy savings - at a high price A31

Oil ministers representing the 13 OPEC nations broke up an informal meeting in disagreement tonight over a Saudi Arabian plan for a new range of oil prices that would raise the cost of Saudi Arabian crude but roll back prices charged by several other producers. The ministers plan to continue the meeting of the Organization of Petroleum Exporting Countries tomorrow, after consulting with their governments. ''The situation is fluid,'' Sobroto, Indonesia's oil minister and chairman of OPEC, told reporters afterward. ''The mountains are higher and the valleys deeper than I expected.''

Libya accused the United States tonight of ''international terrorism.'' The charge came in a note of protest delivered to the Belgian Embassy, which looks after American interests here in the absence of direct Libyan-American diplomatic relations. The note resulted from the air clash in which the United States said two of its carrier-based fighters shot down two Libyan planes about 60 nautical miles off Libyan territory. Libya said the action, which it denounced as aggression, occurred ''within Libyan territorial waters.''

Wall Street appears convinced that the nation's budget deficits are going to be higher than the President has predicted, thus preventing or delaying the long-awaited decline in interest rates. An Administration official conceded earlier this week that, without more cuts, the fiscal 1982 budget deficit was likely to balloon to $60 billion. The President's goal was to hold it to $42.5 billion this year and balance the budget in 1984 -goals the investment community decided long ago would not be realized. Long-term Treasury bond yields are hovering around a near-record 14 percent, compared with 12.1 percent when Mr. Reagan took office, largely because of fear that the Treasury and Federal agencies will have to borrow heavily to finance the deficits.