The Montgomery County Council voted last night to defer a long-awaited decision on whether to allow a rock quarry in the placid, largely rural community of Boyds.

On a separate issue, the council voted along factional lines to place tough restrictions on members of the county's two new cable television citizen advisory panels. The selection of members for those panels had become the latest focus of a continuing struggle between County Executive Charles W. Gilchrist, who opposed the restrictions, and Council President David L. Scull, who proposed them.

The decision to delay a vote on the rock quarry was greeted with sighs of relief from about 250 Boyds residents opposed to the quarry who packed the council chambers. A council committee has already voted to approve the quarry, and residents said they believe the delay by the full council would give them more time to lobby against the project.

"We're very happy!" said an elated Bernice Clipper, 57, a Boyds native. "We have our own wells dug in our yards. That quarry would definitely have an impact [on the well water.] I just think it would be terrible, terrible."

The quarry proposal has been one of the county's longest running controversies, pitting a vocal citizens group against Rockville Crushed Stone, the firm that wants to establish the quarry. Boyds residents think their rural way of life would be disrupted by the traffic of heavy trucks traveling to and from the quarry.

The council committee voted to approve the quarry only on the condition that the rocks be shipped out by rail during the initial operatiion, until roads can be widened. Other conditions included noise controls and monitoring along the truck route.

On the cable television bill, Scull's council majority voted to prohibit members of either the Cable Television Advisory Committee or the Cable Television Corporation Task Force from participation in partisan political activities. Members of those panels would also be prohibited from holding a county job or from working for the cable firm for up to three years after serving as a panel member. Members would also be subject to discharge by the council.

Gilchrist opposed the restrictiions as too strict because the positions are voluntary; and the panels only advisory, with no decision-making power. The advisory committee will make recommendations on fees and rates, while the other panel will draw up bylaws for a new cable television corporation that will oversee operation of two channels reserved for county government use.

A Gilchrist aide said after the vote that the executive would study the bill further before deciding whether to sign or veto it.

After a marathon all-day session in advance of a month-long vacation, the council also:

* Cleared up a legal hitch that had blocked the hiring of a Baltimore lawyer to probe allegations of abuse in a federally funded job trainig program. Howard Rosenstein will conduct the probe on behalf of the county's Merit Systems Protection Board as a "special investigative counsel." He was originally hired for the job two weeks ago but his contract was put in jeopardy because he was not licensed as a private detective or investigator with the state police.

* Approved a new contract with the Georgetown University Law Center to provide legal services to the council, as it attempts to rewrite the county's complex and archaic code into "plain English." The selection was never really in doubt, because Georgetown's Anne Blaine Harrison Institute for Public Law was the favorite choice of Council President Scull.

* Approved $8.5 million in tax-exempt bond financing to allow a county biomedical firm to construct a new corporate headquarters and research facility just off Shady Grove Road. The firm, Microbiological Associates, becomes the first tenant on a huge tract of county-owned land that officials hope will become a magnet for biomedical firms.

Divided up a new $1,050,000 federal grant among 19 programs and groups. The money, a block grant received as part of a new federal emergency jobs bill, was to be used for public service work and to help the unemployed, and more than 70 community organizations and special interest groups competed for the funds.

The projects and groups receiving some of the funds include the Takoma City-Wide Paint Program, which helps persons paint their homes; the Housing Opportunities Commission's summer program to employ about 30 youths, and the National Business League of Montgomery County, for its program to employ summer interns in the business world.

Those who lost in the heavy competition for funds included the Hispanic Coalition, the Maryland Vietnamese Mutual Association, and Delta Sigma Theta Inc., which requested $248,000 to help treat hypertension among blacks.