Arlington's cable television advisory committee has scheduled a May 13 public hearing to solicit citizens' views on the quality of the county's privately run cable television system and suggestions for improving it.

Joseph D. Lewis, chairman of the County Board-appointed committee, said the hearing was a condition the county imposed on the system's owners when the board extended the life of the franchise contract.

The 35-channel system, known commercially as Metrocable, was sold in 1983 by a predominantly locally run firm for $33 million to Arlington Cable Partners Inc., a group formed by Gustav Hauser, former chief executive of Warner-Amex Cable Communications, and Odyssey Partners, a New York investment concern.

At the time of the contract extension, the County Board said the system's owners would have to demonstrate at the hearing that they had complied with the provisions of the contract.

That contract spells out dozens of details on such issues as the quality of the signal; procedures for handling consumer complaints, and the use of some channels by the county, the school system and the community.

The agreement also stipulates that Metrocable must prove that the system is "consistent with then current state of the art" for the industry and submit plans for increasing channel capacity.

"They're pretty much in compliance" with the contract, Lewis said, adding that the system is nevertheless "not state of the art today. The question that needs to be decided is whether the system should be brought into the state of the art."

"In that sense," added Gary Smyth, the county's cable administrator, "there is a real concern as to whether Arlington is getting what it bargained for in the original agreement ."

Smyth added that John D. Evans, Metrocable's executive vice president, was quoted in an industry magazine as saying that systems with 118 channels do not really appeal to the average consumer and that 60 channels are "more than adequate."

Evans could not be reached for comment. But Lewis said that Metrocable has advised his committee that a private consultant whom the firm hired to study a possible expansion of channels has recommended against it. The consultant cited rapid changes in cable technology that could make a system redesigned today obsolete by the 1990s.

Lewis said Metrocable, which serves about 30,000 county households, could expand to 54 channels today without laying new cables.

Metrocable officials are expected to address the expansion issue at the May 13 hearing, scheduled for 8 p.m. in the County Board room at the courthouse.

The hearing, which is scheduled to be broadcast live on cable channel 31, also will cover such questions as adequacy of video and audio signals are adequate, diversity of programs, monthly rates and a variety of other issues.

The committee will take live telephone calls from viewers during the hearing.