On the face of it, you wouldn't find anything to connect Pat Patterson and Ronald Reagan. She's an animated, cinnamon-skinned woman with two teen-age children who works as a $17,000 service representative with the C&P Telephone Co. She lives in far Northeast Washington just off Kenilworth Avenue, in a complex of garden apartments called Mayfair Mansions.

Once the apartment complex boasted grassy malls with shade trees, and the three-story buildings were neat, with ivy on the walls. Now Patterson describes the dwelling as "a slum, really."

On June 1, Patterson received notice that, beginning this Wednesday, she would be expected to pay $100 more a month in rent, for a total of $422. She says there is no way she can squeeze this much out of her no-frills budget. She owns no car and both her sons work when not in school.

People like Pat Patterson are caught in a kind of Catch-22. Mayfair is privately owned, but the government subsidized its mortgage. On top of that the government--in the form of the federal Department of Housing and Urban Development--gives additional subsidies to three-fifths of the families who live there, but Patterson can't qualify because she makes too much money. Meanwhile, the city doesn't have any other private housing that she can afford and so, despite Mayfair's condition, she'll stay. She can't find comparable housing at an affordable price.

Arthur Reynolds, manager and part owner of the property, maintains that the rent increase is needed due to a dramatic increase in utility costs and in order to correct housing code violations. He adds that, as similar properties go, Mayfair's rent is relatively low, even with the increase.

Patterson argues that increased P utility costs result in part from rotting window frames and poorly insulated doors. The problem is long-term neglect and poor day-to-day maintenance, she argued to HUD. But the tenants' objections were to no avail.

HUD spokesman Patricia Rouse said the increase was approved only because the owners needed it to pay the costs of operating the complex. In the past, when costs rose, owners of subsidized housing went to Uncle Sam to get bailed out. Now it has to come from the tenants. And people like Pat Patterson are asking, "Where is the money going to come from?" Replies HUD's Rouse, "I don't know the answer."

"How could HUD approve an increase that big and not give us time to figure out how we are going to pay it?" Patterson asks rhetorically. "This is the agency with responsiblity of protecting people who need housing. You feel so helpless! "

Tens of thousands of D.C. residents are plagued by the problem of finding a decent place to live. More than 11,000 families pay over 35 percent of their incomes for rent; some 7,000 families are on the waiting list for public housing. An estimated one-third of the city's rental units and thousands of houses are in serious need of repair, while thousands of houses are boarded up. All this while the average cost of buying a two-bedroom house is estimated at more than $100,000.

The fact is, in Washington today you need some $500 to $600 a month for a two-bedroom apartment. But wages aren't keeping pace, and inflation has reduced the value of the dollar.

Still, Ronald Reagan has said: No S more subsidies. The Reagan administration would like to get out of the business of subsidizing housing for the poor almost entirely by 1984 or 1985, and plans to build subsidized units only for the elderly in the fiscal year beginning in September. The administration is requiring tenants in subsidized housing to pay a larger share of their incomes for rent, and to earn less to qualify.

So Pat Patterson and the others at Mayfair are yet another example of how under Ronald Reagan the poor and working poor are going to have to pay more for everything they get. In Pat Patterson's case, she says she's going to have to take on an extra job to pay for an apartment at a complex in which she is ashamed to live.

"Most of our halls and fronts get cleaned once every two or three months, if then. They're never waxed and never painted," she says. "There're no front doors on some of the buildings." And she still is reeling from that one-month's notice that she must now come up with an extra $100 for rent.

That notice, she says, hit like a bolt of lightening.