Solon Automated Services reported record quarterly profits of $2.1 million (68 cents a share), a 25 percent gain over earnings of $1.6 million (54 cents) in the second quarter of last year.

Revenues for the quarter ended March 31 climbed to $22.6 million from $19.9 million for Solon, which is the nation's biggest supplier of coin-operated laundry equipment to apartments and also owns the Sugarbush Valley resort in Vermont.

For the first half of the year, Solon posted profits of $3.6 million $1.17) on revenues of $43 million, compared with earnings of $3 million (98 cents) on revenues of $37.5 million the prior year.

Annual profits of Smithfield Foods plunged from $3.5 million ($.48 a share) to $873,000 (45 cents) last year, though part of the drop was due to an accounting change.

Sales of the Virginia meat packer climbed to $218.3 million from $193 million last year.

A switch to last-in, first-out accounting for inventories cut earnings by $1.1 million, the equivalent of 57 cents a share. But Chairman Joseph W. Luter III said the total decline "was indicative of industrywide problems." He said all pork packers have been hurt by sharp fluctuations in hog prices and severe price competition caused by industry over-capacity and large stocks of frozen pork.

San Juan Racing Associates reported its annual earnings climbed to $4.3 million (64 cents) and would have been even higher except for belated write-offs from the sale of the Washington Diplomats professional soccer team three years ago.

Through its SJR Broadcasting subsidiary, San Juan Racing owns Washington radio stations WUST-AM and WJMD-FM and eight other radio stations. The company also operates a race track in Puerto Rico and until 1978, owned the Dips.

The sale of the soccer club to Madison Square Garden Corp. led to a $776,000 write-off this year that reduced earnings by 18 cents a share.

The race track produced revenues of $24.6 million and profits of just over $1 million, the company said, while the radio statins took in $25 million and made $2.5 million in profits, the company said.

San Juan Racing, which is controlled by Washington investors, has agreed to sell nine of its 10 radio stations to Gulf Broadcasting Group, a subsidiary of Gulf United Corp. of Jacksonville, Fla. Gulf United is the parent of Equitable General Life Insurance Company of McLean.

Jefferson Bank & Trust Co. of Capitol Heights posted a pretax profit of $100,000 for the three months ended March 31 -- its third quarter of operation. The bank, which began business last July, had pretax earnings of $21,000 for its first six months.

Assets increased 17 percent during the quarter to $8 million, and deposits climbed 11.3 percent to 5.3 million.