George W. Johnson trekked up to Capitol Hill yesterday looking for a job for perhaps the hundredth time, and he was angry that fellow Maryland Leslie Pfenninger managed to land a federal job by telephoning President Carter over a national radio hookup March 5.

"That's crazy!" exclaimed Johnson in frustration. "Just because of the way an electronic hookup worked she got it, but she was representing a large group of people who were crying out, asking the same question and it went answered."

While Pfenninger was lucky and got a job from a federal manager who admired her "guts" for calling the President, Johnson is perhaps more representative of the legions of frustrated job hunters in the Washington metropolitan area.

Indeed, his 10-month Odyssey of job-seeking has led him to the melancholy conclusion that "if one is going to succeed on the Hill or in the Civil Service (job hunt) in this city, it's who you know and not what you know that counts."

Johnson said he has applied for more than 100 jobs since receiving the doctorate in political science from the University of Maryland in May, 1976. He hasn't been granted one job interview.

Almost daily, the 33-year-old New Carrollton resident goes to Capitol Hill and makes the round of congressional and senatorial offices, dropping off his nicely printed resumes and rechecking possible job openings.

Yesterday his first stop was the office of freshman Sen. John H. Chafee (R-R.I.) who is looking for a legislative assistant in international affairs - a job Johnson feels qualified for by his academic training and his three years of Army Intelligence service.

But there doesn't appear to be much hope he'll get that job. "I've got a huge file drawer full of resumes," said Chafee's legislative secretary, Cynthia Lerch. "I would estimate over 1,000 of them. Sometimes I get up to 10 resumes a day."

Johnson said he was told by a secretary in Chafee's office, "If you don't have Hill experience you can forget it.' It's an incestuous society up here. They hire one another."

Johnson said applying for a Hill job is a "Catch-22" proposition because "You can't get a job unless you have Hill experience and unless you have a job you can't get Hill experience." He has not worked in a political campaign of a successful candidate, a normal entry route for inexperience people.

"I'm sure they could paper the Capitol with my applications," he said. "I've been up here three to five hours a day ever since May (1976)."

Johnson said he frequently bumps into friends and former students of his, also looking for jobs. He said when he dropped off his resume at the office of Sen. Paul S. Sarbanes (D-Md.: a secretary in the office told him she had received 15 unsolicited resumes in two hours.

Hill jobs, of course, are not controlled by the Civil Service. But Johnson has been on Civil Service registers, he said, for more than two years and hasn't had any luck there, either.

He said he applied for 30 to 40 positions posted on the Library of Congress bulletin boards. He received no response, he said.

Pfenninger, a 21-year-old Lanham woman, told President Carter March 5 she found "the doors completely shut" to Civil Service jobs and she asked "If the restrictions will be lifted to permit individuals like me to compete for jobs now only open to those currently in Civil Service or those of a reinstatable status."

Instead of answering the question, Carter said he would check her "particular case" and that she would receive a call about her prospects for employment.

A Civil service spokesman said yesterday that when a manager in the federal system wants to fill a vancacy he can promote someone in the organization, reinstate a person who has been in the organization or hire someone from outside.

In any case, the spokesman said, the manager must post the vacancy on public bulletin board. But if such a posting says "status required," someone from the outside isn't eligible.

This system may be the source of much of Johnson's frustration, the spokesman suggested, and it is probably to what Pfenninger referred.

The spokesman also mentioned these other sources of frustration for federal job seekers:

A law stipulating that career federal jobs in the national capital area be apportioned among states on a population basis, making it difficult for Maryland, Virginia and D.C. residents who are generally over-represented by job holders.

A White House requirement to fill only 3 of 4 federal job vacancies after Feb. 28 and until new federal agency job ceilings are established to promote efficiency in the federal bureaucracy.

Rules that give veterans an edge over nonveterans in getting federal jobs.

Johnson said he is frustrated by another practice the Carter administration has vowed to do something about - "double-dipping" by military retirees who also hold full-time jobs.

"For one position I was competing with two retired generals and a former assistant secretary of defense," Johnson said. "They get two paychecks instead of one, and they get commissary, PX, medical, dental care for themselves and their families for the rest of their lives - and they're telling me that they deserve a second job when I don't even deserve a first job!"