Micro General Corp. reported net income of $30,480 for the third quarter. It lost $297,093 in the year earlier. Revenue rose 51%, to $1.3 million from $870,497. For the first 9 months, net earnings totaled $202,668. It had a loss of $307,568 for the like period in 1987. Revenue increased 42%, to $4.4 million from $3.1 million. In keeping with its turnaround strategy begun 2 years ago, the company said it is continuing to invest heavily in strengthening a distribution channel of office equipment dealers and in development of new products. Irvine-based Micro General manufactures microcomputer-based shipping systems and postal scales for use in shipping departments and office mail rooms.