Several days ago, an item appearing in a self-styled conservative publication here was posted surreptitiously on a bulletin board at the Voice of America's Washington headquarters.

"Ken Tomlinson," it read, "the bearded bright new boss of the Voice of America, was the guest of honor at a black-tie bash hosted by Roy Cohn at the Madison last week. Puckish Roy, who went on to become a big-time Big Apple barrister after helping to convict the Rosenberg atomic spies and expose other termites in the nation's woodwork, presided from a table marked 'Siberia.' "

To those with lengthy service at the VOA, that item stirred old memories and raised new fears. It seemed to confirm what many there have been saying privately for months: that once again the Voice of America appears headed into divisive ideological combat. For them, Roy Cohn represents more than just someone who played a role in the controversies of 30 years ago. He was the principal investigative aide to the late Sen. Joseph R. McCarthy, the Wisconsin demagogue, in the days when one of the preeminent targets of what has come to be known as McCarthyism was the VOA.

Let it be said immediately that more than one irony flows from this incident. The most shameful aspect of the hunt by McCarthy and Cohn for subversives in government was the way they wrecked the careers of innocent, patriotic people by employing the despicable tactic of pronouncing them guilty because of their associations. So one banquet does not a conspiracy make.

And Tomlinson, a professional journalist of high credentials with long service as a Reader's Digest correspondent and editor in the United States and overseas, certainly doesn't see that dinner, or that association, as anything out of the ordinary. Cohn is an old friend from New York, he says. Tomlinson adds that he while he might be considered in the neo-conservative political mold, or as a Jack Kemp supply-sider, he is determined to resist any pressures, from whatever side, that would compromise the independence of his organization.

Still, it's understandable that veteran VOA employes found this incident disquieting. It comes after a long and troubling period at the VOA. At the heart of the internal problems lies an old concern: whether this agency, now in its 41st year of broadcasting news of America around the world in 42 languages, will maintain its journalistic integrity or become a government propaganda arm.

As Tomlinson takes control, these questions assume more than casual interest. Central among them is whether the Reagan administration, probably the most ideologically minded in decades, if not in this century, will attempt to impose ideology over professionalism.

From what this reporter has been hearing for some months now, morale at the VOA has plummeted. Persons have been abruptly transferred, and some have resigned in protest.

Turnover at the top has been high, with Tomlinson becoming the third director in only a year. Above all are open concerns about the agency becoming politicized and embarking on a sharply more ideological role.

One career employe of long acquaintance remarks that he has served eight presidents, four from each party, experienced the embittering McCarthy period, and went through the difficult Vietnam/Watergate years. Yet recent months, he says sadly, have been the worst of all. For the first time, he fears that the agency's basic structure will be so torn apart that it will never be repaired.

Veterans cite the language of a letter of resignation by an announcer late last fall as reflecting the views of many.

"I truly wish I could express regrets at having made this decision," Shepherd D. O'Neal wrote. "I cannot. There are too many motivations--some of anger, some of sadness--all of compelling nature."

He went on to explain:

"I never was a good salesman and, with the new vile soap VOA been pitching to the world, I have found myself increasingly choking and feeling less pleasure and pride in the work that has given great pride and pleasure . . . . I don't believe that reviling the Soviets will make them fold into submission. I don't believe the Japanese can be intimidated into less productivity or less enterprise. I don't believe South Africa has the right to anything less than the censure of civilized nations. And I don't believe the way to help people is by deliberate trauma and uncaring pursuit of ideology and wild hunch.

" . . . I decline to be drawn any further into the self-defeating vortex of propaganda; this vision of America I cannot share."

Others point to actions and comments by United States Information Agency Director Charles Wick, VOA's superior, as signaling a wish for more ideology and less professionalism. In one of his early moves, Wick overlaid the editorial management at VOA with two new, top-level policy positions, a deputy director for policy and plans and a deputy program manager for commentaries and analysis. These came with internal agency memos advocating a new assertive propagandistic role.

Wick stirred further concern when he was quoted more than a year ago by a Scripps-Howard newspaper writer as saying, "One of the problems that we have at the Voice is that they favor the other side. If anything, the Voice erred on the side of imbalance, against us."

A subsequent Newsweek magazine quote, attributed to close associates of Wick, said he suspected that " . . . not only are some staffers 'communist dupes' but that the VOA itself 'may have been penetrated.' " It was instantly denied as reflecting his views. But, again not surprisingly, these heightened internal agency concerns have formed a backdrop for the latest director's assumption of power.

Tomlinson is a personable, articulate, unassuming sort who certainly gives off no sense of the burning zealot. He's a pro. In conversation, he stresses that he means precisely what he said at his confirmation hearing before Christmas:

"When I was first introduced to Voice employes, I asserted that in the months and years ahead they would see my dedication to the charter that governs all we do. They would see that I believe strongly in the importance of preserving VOA's reputation for truth and objectivity so vital to our credibility abroad."

Such words run through his comments when he speaks about what he hopes to accomplish at the VOA. And, he adds, in comments aimed at internal critics:

"I don't believe the people who expressed concerns to you have been listening to what I am saying or watching what I am doing."

Fair enough. We'll try to do just that and report on the results.