The stock market, which has been backing...

The stock market, which has been backing and filling these past weeks, was rudely interrupted by the 101-point drop Thursday in the Dow Jones Industrial average, according to Irving Katz, director of research for Thomas Green/San Diego Securities.

Unfortunately, this sudden free fall eliminated weeks of base-building by some San Diego stocks and wiped out most of their struggling gains in one day, Katz said.

Among those down for the week were Home Federal Savings & Loan, $1.75; Cubic, 1.375; Advanced Marketing Services, $1.25; Price Co., $1.25, Mailboxes Etc., $1, Rohr Industries, $1; and Synbiotics, $1.

Foodmaker dropped $1.125 to $11 upon completing its acquisition of Chi-Chi’s. The company also announced its intention to borrow $200 million to fund the acquisition.

The only gainer marking a new high this week was Cohu, which climbed $1 to $10, where it was still selling at 9.75 times its 1987 earnings of $1.03 a share.

First National Bancorp gained $.50 to $9.50. San Diego National Bank, which appeared to drop $.625, was actually selling without its 9% stock dividend, according to Katz.

DH Technology, which recently announced an acquisition that will double its revenue base, will hold its annual meeting next Monday at 10 a.m. at the Sheraton Grand on Harbor Island.