In the mid-1970s, a small group of Jewish men at Washington's Adas Israel began holding a more traditional Sabbath service than the one attended by the rest of the congregation. All in Hebrew, it featured a longer Torah reading and was led by the men instead of a rabbi and cantor.

But in the early 1990s, when the men could barely muster a minyan--the minimum of 10 Jews needed to hold the service--they took a fateful step to save it. They invited women to join and have equal prominence in various liturgical roles.

What happened next surprised everyone. The tiny prayer circle became a cluster, then a flock, then a crowd. The "Traditional Minyan," as it is called, is now a semiautonomous community within a larger congregation of 1,800 families. The weekly service at the Northwest Washington synagogue is attended by 150 to 200 mostly young Jews, who relish what they say is rare in the area: a blend of undiluted ancient rites, modern gender equality and opportunities to participate.

Tonight, as Jews begin the eight-day festival of Hanukah, some say the minyan's vitality is yet another indication of a return to tradition throughout Judaism--and an illustration of the holiday's story of temple rededication.

"It is evidence that there is religious excitement in our movement," said Jeffrey A. Wohlberg, senior rabbi at Adas, the area's largest Conservative movement synagogue. "We're pleased to have so many young people who want to pray and who take the Jewish religion and Jewish life so seriously and so personally."

Within 130-year-old Adas, however, the minyan's explosive growth initially was seen by many longtime members as a threat to congregational unity. For a time, Adas seemed a Jewish reprise of "Upstairs Downstairs," as the minyan convened in the nursery school on the lower level while regular services took place a floor above in the main sanctuary.

Even Wohlberg was troubled at first. "A little piece of me," he acknowledged, "said I'd like everybody to pray together in one service."

But in the six years since the minyan's resurgence, and despite some persistent disagreements, the two sides have managed, through compromise, to preserve Adas's unity.

"So far, this is something going on in the middle of Adas and that's a wonderful thing," said minyan-goer Steve Rabinowitz, 42, who runs a public relations firm. "I hope I would never have to choose between the minyan and Adas."

The minyan service, which is popular with young singles and sometimes outdraws the main service, now takes place in the 275-seat Kogod Chapel on the same level as the synagogue's 1,500-seat sanctuary. On a recent Saturday, the atmosphere was relaxed and lively, the predominantly 20- and 30-something crowd sprinkled with older people and children. Several men and women covered their shoulders with Jewish prayer shawls.

Unlike the main service, the minyan doesn't have a cantor, choir, musical instruments or microphones--the latter regarded as electronic enhancement prohibited on Sabbaths under strict Jewish law. Also, the minyan does not use a bimah, or a pulpit.

Members take turns chanting the Torah and giving the homily--the only part of the service in English. By reading more of the Torah than the main service, the minyan completes the five books of the Old Testament in one year instead of three.

Such liturgical purity brings the minyan services closer to those held at synagogues of the Orthodox Movement. Some in the minyan jokingly call their services "Kesher Lite," a reference to the Orthodox synagogue of Kesher Israel in Georgetown. At Kesher, however, men and women sit separately and women do not help lead the worship.

"In other services, usually there is one person who does the praying, and they do it from the bimah. So it's almost like you're being preached to," said Judith Hellerstein, 34, who heads her own market research firm. "But in the minyan, it's more a feeling of community participation. You really feel like you belong. There's a lot of singing, too. It's just a very warm feeling."

Integrating the independent-minded minyan, which like any group has its share of hard-liners, into the established Adas community was not easy. Old-timers resented upstarts implying the minyan was a more authentic service. These critics wanted to know why the group didn't pray with them and why its members didn't help prepare food for kiddush, the post-service social attended by both groups. And, asked pointedly, how many pay dues?

In response to such concerns, the synagogue adopted a sliding dues scale, and a majority of minyan members now pay dues. They help prepare the kiddush. They have representatives on the synagogue's governing board and ritual committee.

When the minyan, which is informally run by a five-member volunteer coordinating group, wanted to hold baby-namings and prenuptial blessings called auf ruf, Wohlberg and synagogue leaders came up with a compromise: Such ceremonies would be done twice, once in the minyan and once in the sanctuary with the whole congregation.

"What I didn't want was there to be the sense that there are two congregations with a big 'C,' " said Wohlberg, 58, who came to Adas in 1986. "I wanted to maintain the sense that even though we have multiple services, we are one congregation with one set of rules."

"There are challenges to any rabbi with a service where there's not really that much rabbinical participation, because sometimes it can feel a little bit separate," said minyan member Julia Gordon, who sits on the synagogue's board.

"But in the last few years, we've worked hard to make sure everyone feels part of one community. As time has gone on, the relationship has grown and really become very cooperative in many ways."

Wohlberg does not believe the minyan spurns Adas's three rabbis "as clergy per se," he said. "I don't think there is a rejection of our role, our purpose, our position." But he bristles at suggestions that the main service--conducted mostly but not entirely in Hebrew--is unfulfilling or restrictive to women, who at Adas have long had the same liturgical privileges as men.

"Everything at Adas is egalitarian," he said. "This is not a static place. We've made lots of changes over the years in order to make the service more attractive, more participatory, more authentic and less rigid."

The issue of the moment is festival days. On major Jewish holy days such as Yom Kippur, synagogue attendance is so high that it is not feasible to hold just one service. But on lesser-attended festival days such as Sukkot and Passover, Wohlberg and the main congregation would like everyone to pray together. On those days, synagogue leaders agreed to forgo musical instruments--but not microphones.

But some members of the minyan don't accept that and still want their own service. "So," Wohlberg said, "we're talking about it."

As the minyan ages, more tensions are likely. Wohlberg said he wants b'nai mitzvahs, the important coming-of-age rite for Jewish children, celebrated in the main sanctuary. Minyan loyalist Jessica Nemeth is not so sure.

When her 6-month-old daughter is ready for her bat mitzvah, "I think it's going to be very important to me and my husband that it be in our community, and our community is the minyan," Nemeth said. "We're certainly not going to have two bat mitzvahs! I hope that in 12 years from now, we will have figured that out."

What both sides seem to agree on is that the minyan's impact on Adas will be long-term. "It is here to stay," Nemeth said.

Wohlberg expects that many in the minyan will "move through the ranks to leadership of the synagogue." But, he added, "I don't know the outcome, what will happen in 20 years."

For now, he prefers to focus on the minyan's larger significance.

"I think this is good for Judaism," he said.

CAPTION: Julia Gordon, left, Shoshana Danon and Alvin Dunn talk before a minyan, a more traditional worship service, at Adas Israel Congregation.