Members of the San Francisco Symphony orchestra ratified a new three-year contract on Sunday, ending a two-week strike that caused the cancellation of eight concerts. The orchestra was scheduled to resume its normal subscription concert schedule beginning Tuesday in San Jose before leaving Saturday for a 26-day, seven-city Asian tour. Musicians voted 78-18 to accept the contract that gives them a minimum weekly compensation of $975 the first year, $1,020 the second year and $1,050 the third year. Compensation had been $915 a year. The agreement also lowers musicians' retirement age to 62. Under the previous contract, wind players could retire at 62, but other musicians could not get full pensions before 65.