PORTLAND, ORE., AUG. 21 -- Rep. Patricia Schroeder (D-Colo.) headed off today on a two-week break from politics, with fresh financial and political encouragement to join the race for the 1988 Democratic presidential nomination next month.

Schroeder, the eight-term House member from Denver, was urged to run by many of the prominent Democrats who turned out to cheer her appearance at the National Women's Political Caucus (NWPC) convention here Thursday night.

She also picked up heavyweight fund-raising help in the form of billionaire Marvin Davis, who has agreed to host a Schroeder fund-raiser among his friends in the oil and entertainment industries.

Schroeder's staff said the fund-raiser will be held at one of Davis' houses on Oct. 29, a date that may be significant because it is a month after the deadline Schroeder has set for a deciding whether to enter the race.

Schroeder's announcement of the helping hand from Davis -- a longtime friend whom she described as "a big, big fish" -- came at the end of a busy week in which she seemed to move decisively toward getting into the race.

Schroeder recruited a national financial chairman with clout among West Coast liberals, Gary David Goldberg, executive producer of NBC television's "Family Ties." And she put together an ambitious schedule for the last week of September leading up to her final announcement.

On Sept. 20, Schroeder will speak via a television hookup to "Run Pat Run" rallies in homes and meeting halls around the country. Three days later, she will address the National Press Club in Washington, D.C., an appearance that should make it clear which way she is headed. Her formal declaration is scheduled for Sept. 29.

Here in Portland, Schroeder told 400 women activists at the NWPC that she has collected $750,000 in cash and pledges in the past month's exploratory tour of 27 states.

As she has done in other appearances, Schroeder concentrated more on the expertise she says she has acquired on defense issues in her years of service on the House Armed Services Committee than on traditional women's issues. "Every year I have been on the committee," she said, "I have submitted an alternative defense budget. And mine have always included mine sweepers," a reference to the embarrassment the Navy experienced in having to scramble for that type of ship for Persian Gulf convoy escort duty.

Schroeder's potential candidacy drew an emotional endorsement this morning from one of the "founding mothers" of NWPC, former representative Bella Abzug (D-N.Y.).

Calling Schroeder "the single most visionary, qualified candidate" in the field of declared and possible contenders, Abzug said, "It is crucial for women in this country to have a voice that is distinctly our own."

Interviews with Democratic officeholders here found almost universal encouragement of her candidacy, even from women committed to other aspirants.

Iowa Lt. Gov. Joanne Zimmerman, who is supporting Sen. Joseph R. Biden Jr. (D-Del.), said, "Every time she is on stage, it means more attention is paid to the women's agenda. I don't expect Pat Schroeder to win, but her running means all the other candidates have to address that agenda."

Minnesota Lt. Gov. Marlene Johnson, who is uncommitted, said "it would be great" for Schroeder to run. "From now on, it's critical we have a woman running for president all the time. And she will be a credible candidate."

The other side of the coin, expressed in many interviews, is that few, if any, female politicians -- eager to protect their reputations for keeping their commitments -- are likely to abandon other candidates to aid Schroeder.

Zimmerman and Vermont Gov. Madeleine Kunin (D), the convention keynote speaker here and a supporter of Massachusetts Gov. Michael S. Dukakis, made it clear that they will stay with their original choices. And Johnson, after talking enthusiastically about the turnout for Schroeder at a recent Minnesota reception, said she will not decide who to support until Minnesota Gov. Rudy Perpich (D) makes his choice.

Only a few skeptics could be found. Lacy Maddox, a Raleigh, N.C., activist, said she is "very impressed with her {Schroeder's} grasp of defense issues and her willingness to take on the powers that be. But I think she needs some work on her presentation. She slumps. She uses her hands a lot. And her voice jumps around. She's not very presidential."

But far more agreed with state Rep. Gloria Segal of Minnesota, who said, "Even if she loses, it's all right. Women often lose the first time we try for any office. Win or lose, it's a win for her to run."

Goldberg, the television producer, said he has known Schroeder for years and has urged her to run. He said he expects her to become a candidate; indeed, he has no plans to schedule fund-raising events until she formally announces because "that gives me a lot more credibility when I ask people for help."

Since her abrupt announcement in June that she would "take a hard look" at a race for the White House, Schroeder has been barnstorming the country to test the strength of her message and to solicit financial support. The response in most places has ranged from strong to wild enthusiasm, but her fund-raising has not kept up with the goals she set for herself two months ago.