Increases in earnings per share of 10.9% on a 14% sales increase marked the 1986 year for Lexington, Mass.-based Raytheon Co. The sales growth and improvements in operating performance during 1986 were broadly based, a spokesman said. Electronics, Raytheon's largest business segment, accounting for 59.4% of 1986 sales, continued to make the greatest contribution to the company's growth. Defense electronics systems again performed strongly over a wide range of diversified programs, the spokesman added. Also, sales of the Beech Aircraft subsidiary increased 16.9% to $868 million, compared to $743 million in 1985.