SAN DIEGO

Systech, a privately held computer products manufacturer, announced a $379,507 profit for 1984, more than double 1983’s total. Sales also doubled, reaching $3.7 million.

Rancho Bernardo Savings Bank recorded net income of $10,654 during the quarter ended March 31, compared to a $5,497 loss a year earlier. Assets jumped 162% to $30.4 million.

The Jeweler’s Exchange Building in downtown San Diego, built in 1913 as the city’s first high-rise, will be converted into The Gaslamp Plaza, a hotel with a turn-of-the-century motif. Rancho Santa Fe National Bank and Hidden Valley National Bank have signed a letter of intent to merge the two institutions, pending shareholder and federal regulatory agency approval. The resulting bank would boast assets of $80 million and a capital base of $7.5 million.

The Greater San Diego Chamber of Commerce reported that 28.8 million people visited San Diego during 1984, a 1% increase over 1983’s total. Tourism remains the area’s third-largest industry sector, behind manufacturing and the military.

Signal Environmental Systems, a unit of The Signal Cos., has signed a contract for $30 million to build a 200-ton-per-day waste-to-energy plant in Claremont, N.H.