National Technical Systems Inc. reported first quarter net income Friday of $728,000 (8 cents per share), a 23 percent increase compare to $591,000 (6 cents per share) in the same period a year earlier.

Sales for the Calabasas-based defense industry technical services provider rose 6.5 percent to $31.7 million, thanks to an 8.9 percent hike in sales from the company’s engineering and evaluation division

“I am pleased with our first quarter results considering the difficult economic environment. Our backlog is at an all-time high; however total revenues were negatively impacted by delays in receiving test items from manufacturers in the defense industry,” Chief Executive William C. McGinnis said.

Shares in National Tech were down 4 percent to $5.73 in early trading Friday.