More tangible evidence of the Washington Capitals' rise to respectability was furnished yesterday when WTOP Radio decided to broadcast Wednesday night's key Norris Division game at Los Angeles.

The contest was not on WTOP's original schedule, because of the expense involved and because the Bullets' 9:30 contest will be broadcast from Denver. However, the Capitals are only six points behind Los Angeles in the struggle for third place and a playoff berth, so the 11 p.m. game with the Kings will be picked up in progress when the Bullets end, about 11:30.

"It's too important for the Capitals not to broadcast it," said Peter Lund, WTOP's vice president for radio. "It's the first legitimately critical game in the team's history. In terms of the race, they've got a serious chance for the playoffs."

There is no way to break down ratings for individual hockey broadcasts, but Lund said that for the 7 p.m. to midnight segment, "our ratings are very good, and they are better when sports are on than when they are not."

Lund also called the reaction to the hockey broadcasts "excellent. In phone calls, letters and conversation, there is evidence of wide interest. And when a game is played that we're not broadcasting, we get a lot of negative reaction.

"Hockey fans maybe are smaller in number than baskteball fans, but they seem to be more loyal and certainly more vociferous. They all listen."

WTOP has broadcast the Capitals' games during all three years of the team's existence. It has also been the Bullets' voice for two years. In each case, the contract is up at the end of this season, with WTOP holding an option for 1977-78.

"We're certainly inclined toward continuing to carry both clubs," Lund said. "But if one club got a decent-signal station to carry all its games, I wouldn't stand in the way.

"Our ratings are good, the representatives of both clubs are most cooperative, the reaction has been good and our play-by-play guys, Ron Weber and Frank Herzog, are doing excellent jobs. The only negative point is that with one station carrying both teams, there are some games we can't carry. We get blamed for it and we get letters calling us greedy for doing both teams. But the Bulle't have another station.

"I agree that both clubs should have all their games on. But it's better that we should air 70 games of each than that one should not be on at all."