Intl. Family Entertainment, whose key properties are the Family Channel and MTM Entertainment, showed a net loss for the fourth quarter of $ 51.5 million, or $ 1.26 a share.Revenues for the same period jumped 54% to $ 56.7 million from the same period in 1992. The fourth-quarter dropoff resulted from an extraordinary charge of $ 52.1 million from Intl. Family’s repurchase of $ 55,556,000 of its 6% convertible secured notes. For the year ended Dec. 31, IFE’s net loss was $ 34.8 million, or 83 cents a share fully diluted, brought on by the fourth-quarter extraordinary item. Revenues for calendar 1993 climbed 56% to $ 208 million from 1992. Tim Robertson, CEO of Intl. Family, sees “very positive long-term implications for the growth of IFE’s profitability” from the purchase early in 1993 of MTM Entertainment, which distributes such series as “Rescue 911, “”America’s Funniest Home Videos” and “Evening Shade”; and from the launch of the new ad-supported Cable Health Club and the start-up of a U.K. clone of the Family Channel. Although the U.K. Family Channel lost $ 3.6 million last year and Cable Health Club lost $ 2.1 million, Robertson said the company “expects relative improvement in results of both networks for 1994.” Advertising revenue for the Family Channel increased by $ 10.1 million, or 12 %, in 1993.