A Prince George's County group that last month sought unsuccessfully to convince voters to loosen a strict cap on the county's tax revenue spent close to $20,000 on the effort, about 16 times more than the opposition, according to campaign finance reports filed recently with the county board of elections supervisors.

The group, Citizens for Yes on K, raised $19,689 in its campaign to convince county voters to approve Question K, which would have amended a 1978 law that froze the amount Prince George's can collect from property tax revenue at the 1979 level -- about $143.9 million.

The authors of the 1978 charter addition called TRIM (Tax Reform Initiative by Marylanders) raised $1,232 to oppose passage of Question K, which failed by a 3-to-2 margin in the November election.

The Question K group said that TRIM had been a successful experiment in forcing the government to reduce costs, but argued that it now threatened to force serious cutbacks in county services. Question K would have included tax revenue from new construction in the property tax base automatically and would have allowed the county to increase the amount of revenues by an additional 4 percent each year.

In the first year, the amendment would have raised about $8 million. The owners of a house valued at $70,000, for instance, would have paid about $35 more in the first year.

TRIM supporters, however said any increases would be exorbitant and unnecessary, and produced serveral of their own studies to prove their point.

"People were not fully aware of the consequences of their actions and we were not able to make them fully aware," said John Sisson, president of the Prince George's County Educators' Association, the county's largest teachers union, which was in favor of Question K.

"It's the economy," he added. "People voted their pocketbooks. The opposition very successfully played on people's fears and worries about paying their own bills."

Other union leaders said privately, however, that the felt Question K failed because it was too heavily identified with the teachers union, which saw 507 teachers laid off last spring, and as a result, people without children in the county school system saw no reason to support the effort.

The pro-Question K group received all but about $200 of its funding from the Mayland State Techers Association. The National Education Association donated the rest. Most of the money went to media: $9,460 to Gary Nordlinger Associates for radio advertising and $8,170 to Kelly Press Inc. for printing services.

The anti-Question K group was spawned from a committee that continued to function after the 1978 TRIM victory. The group began with a budget of nearly $20,000 in 1979, most of that from TRIM coauthor William Goodman, a former state delegate who tried unsuccessfully to be the Republican candidate for county executive.

By this fall, however, the TRIM committee was able to contribute less than $100 to the effort to defeat Question K. Most of the funds for the anti-K group, which was renamed Citizens Against K's Excesses for the election, came from the Republican Central Committee, which gave $1,000. Most of that was spent on printing, according to the campaign report.