It was a scene out of the San Francisco of the 1960s.

Across the cloudy panhandle of Golden Gate Park strolled "Uncle Roscoe," a 40,000-hits-a-week LSD dealer, wearing blue jeans, a Grateful Dead T-shirt and a pair of convex black sunglasses that gave him the look of a well-fed bluebottle fly.

From underneath a tree a long-haired blond woman in a flowing dress called out, "Is the store open?"

Roscoe's "store" in an unobtrusive apartment nearby, is wholesaling more LSD than it has since it opened in 1967, and its increased business is just one sign of low-key LSD revival that appears to be centered here.

"Disco people like it, rock 'n roll people like it. Blacks like it, gays like it," Roscoe said as matter-of-factly as a market researcher ticking off the results of the latest consumer survey.

"I just sold a batch to some Navy guys who are going out to sea for six months with nothing to do.

"It's just another high now," he said, drawing from a pipe of marijunana as he sat on a park bench. "Doses are lower, just enough to put a smile on your face, give you a buzz -- not like the heavy colors and trips of the '60s."

Today, Roscoe says, $5 tablets contain 80 to 250 micrograms of LSD, rather than the vision-producing 250 to 1,200 microgram strengths of 10 years ago.

Today's LSD comes of thin gelatine squares, in tablets, and on little pieces of blotting paper stamped with images of dragons and flying saucers.

San Francisco narcotics investigators agree with Roscoe's assessment that LSD is once again melting on tongues and swirling through synapses.

San Francisco undercover narcotics officers have been making a small but regular number of five-to-10 "hit" LSD buys on San Francisco streets recently. Three or four years ago, according to police Lt. Willis Casey, "it wasn't being offered at all."

And the northern California division of the federal Drug Enforcement Administration has seized 750,000 doses valued at $2.25 million so far this year, an "alarming increase" of 1,400 percent over 1977 use, according to Daniel Addario, special agent in charge. That year, all California state, local and federal agents seized only 51,000 doses, valued at $153,000.

"We haven't seen this large supply since the flower children, and supply means demand," said Addario, whose division has recently shifted attention back to the hallucinogen after nearly a decade of pursuing Mexican and French heroin connections.

Addario believes that some of the original LSD chemists are back in business in the Bay Area manufacturing large quantities here. Some, he said, have recently been released from prison..

Last May, however, Sheldon Perluss, 32, the son of a Sacramento Superior Court judge, was sentenced to seven years in prison for LSD manufacture, after he and some companions were arrested with more than 250,000 tablets, the largest seizure of LSD tablets in history. In 1970, Perluss was given three years probation after pleading guilty to selling 21,000 LSD tablets to a federal agent.

Another large seizure of LSD tablets came in 1978 in a large house surrounded by pines in the hills above Oakland. There police discovered 192,000 LSD pills and the body of a murdered LSD dealer who had been posing as a trader in Oriental rugs.

PharmChem Laboratories in Menlo Park, a confidential service that tests drug purity for a fee, reports that over the past two years, LSD has become the third favorite drug sent in, following cocaine and amphetamines.

Last year, the lab found that most of 170 drug samples contained remarkably pure LSD.

Lysergic acid diethylamide, the hallucinogen that gave a generation profound and sometimes terrifying visions, is back without mystical trappings. Few believe any more that the chemical will transform their culture or themselves.

Strollers on Haight Street no longer share money or plume themselves in feathers and robes.

Roscoe looks out of place here. Precious little shops sell antiques and fresh ground coffee. The morning buses are full of short-haired gays and office workers heading for jobs in downtown skyscrapers.

LSD left Haight-Ashbury in the early 1970s. Amphetamine addiction took its place and tore through the remnants of the counterculture. Store fronts were boarded up. College students who once took LSD cut their hair and went to work; others looked for a "high" beyond drugs, in northern California communes and Eastern spirtual groups.

Uncle Roscoe blames the decline in LSD popularity on poor quality control. "People will only buy s--- for so long," he explained, saying that from 1969 to 1976, LSD was "cut" with strychnine and amphetamines.

Dennis Peron, a sometimes San Francisco drug dealer who recently unsuccessfully ran for the city's Board of Supervisors, thinks the Nixon administration also had something to do with it.

"It was a depressing time," he said. "Too depressing to take acid.

"Now the quality is back up, but it's a lot more expensive." By Roscoe and Peron's accounts San Francisco has remained for LSD manufacturing what Detroit is for cars.

"Nine-tenths of the acid in the country is manufactured in the Bay Area," said Roscoe, who claims to have logged 300,000 miles last year between northern California laboratories and wholesale customers in Boston, Washington, New York and Connecticut.

Despite the reported boom in production there seem to be fewer "bad trips" then in the 1960s, perhaps because doses are weaker. Emergency rooms around the Bay Area report a decline in adverse reactions to the drug.

In an unusual incident last Sunday, an unidentified San Francisco woman jumped into the Pacific from a San Francisco rocky point and later told nurses who tended her minor abrasions that she was trying to kill herself and was under the influence of LSD.

But clinicians at the Haight-Ashbury Free Clinic, who comforted hundreds of terrified teen-agers on "bummers" during the 1960s, report "bad trips" are still "few and far between."

"We saw somebody last week on an LSD trip, the first in a long time," said John Walsh, a physician's associate. "He was 26-years-old and he wasn't a hippie. He had been stoned all weekend, and looked at the way he had been wasting his life, and he wanted to talk to us about it. He's going to clean up his act.It was sort of neat."

According to Dr. David Smith, medical director of the clinic, LSD takers today included nonwhites who generally did not use LSD in the 1960s, teen-agers who view LSD use as a "rite of passage," and nonstalgic adults in their 30s who are putting little tablets on their tongues again after a hiatas of several years.

Among those acid veterans are a young, liberal lobbyist and his television producer wife, who took LSD two weeks ago after five years' abstention. After gazing at San Francisco's hills and bays for hours from a green park on the city's Russian Hill, they went home to make love and "reaffirm earlier commitments" made to each other years ago under the influence of LSD.

Then, preparing for their high-powered jobs downtown, they finished up with the escapes of the 1970s -- four banana daiquirls at a local bar, and an hour soaking at a commerical hot tub spa.