Northern Virginia Democrat Ira M. Lechner, financially strapped in his bid to unseat Republican Rep. Frank R. Wolf, yesterday scrapped his long-standing plans for a $30,000 television advertising campaign during the final days of the race.

"We can't compete with Frank on TV and we won't win the election that way anyway," said Lechner campaign manger Donald S. Beyer Jr. He said Lechner, who had hoped to raise funds for the TV ads this past weekend, would instead spend at least $6,000 on radio.

That should place his media costs well behind those of Wolf, a freshman member of the House, who has a $100,000 media budget that includes both radio and television commercials.

Even so, Beyer remained confident about Lechner's prospects and said the compaign might get "something on television before Nov. 2" if it can raise the funds. "I feel comfortable and confident with the tightness of the budget as it exists, but I'd feel more comfortable if we could do TV and attack from all sides," he said.

Fundraising has become a major concern for Lechner, who was reported to be trailing Wolf by 11 percentage points in a recent Associated Press-WRC-TV poll.

Wolf, whose 10th District encompasses northern Fairfax County, Arlington and Loudoun counties, and the cities of Falls Church and Fairfax, began airing his television commercials last month and began advertising on radio in August. Federal campaign financing reports filed last week show that Wolf had raised about $349,000 as of Sept. 30. Lechner, who recently scaled back predictions of raising $400,000, had raised $240,000. Campaign officials said yesterday Lechner has raised about $275,000, compared to the $400,000 Wolf has collected.

Beyer said Lechner staffers obtained "firm commitments" of $25,000 from unions and Democratic contributors during the weekend. The campaign faces huge costs incurred by Lechner's direct mail effort. "We're spending 60 to 70 percent on printing and mailing," said Beyer, adding the campaign has virtually no cash on hand.

"If Ira has any particular bias it is toward his [direct mail] targeting plan, and for completing the strategy," said Beyer. That strategy places a heavy reliance on appeals to senior citizens, Democrats, women and other targeted groups and telephone banks designed to turn out the vote among federal workers and others whom Lechner believes are disenchanted with Wolf and the Reagan administration.

Wolf's TV advertising is fashioned by political consultant Ed DeBolt whose Arlington firm has been paid more than $40,000. Campaign manager Tom Morr said the ads are designed to portray "the tangible visible evidence of Frank's accomplishments like keeping Turkey Run Farm Park open and increasing the use of Dulles Airport."