Mourning did not always become the playwright Eugene O'Neill.

He spent most of his years in a blue funk. In his later years he channelled his sorrow to create the harrowing "Long Day's Journey into Night," but more often his melancholia overwhelmed him.

In "Mourning Becomes Electra"-currently on view in a five-part PBS production that continues with episode two tonight at 9:10 on Channel 26-he tried to stay on top of his own emotions by sublimating them in Greek myth. He modeled his Civil War-era story after the Oresteian trilogy by Aeschylus. But the poetry and the nobility of the original's characters were missing.

"Mourning Becomes Electra" became little more than a long melodrama. Nevertheless, it is such an audacious melodrama, such an unrelenting show, that at times it can stir up the sort of feelings that a good mystery or Gothic thriller does. This "Mourning Becomes Electra" is erratically shot and cast, but Joan Hackett and Roberta Maxwell create some compelling hokum together in the leading roles.

Hackett plays Christine Mannon, the frustrated wife of a wealthy Connecticut shipper who's off fighting the war. Maxwell plays her daughter Lavinia, who resents Mother's affair with a young ship captain and illegitimate Mannon relative.

O'Neill made much of family resemblances in this play, and Hackett and Maxwell look remarkably alike. But Hackett unleashes her passion while Maxwell remains tightly-drawn and calculating. Their confrontations are fiery and fierce, particularly in a high-octane moment nex week when Lavinia dangles some pills in front of her mother as if she were brandishing garlic in an attempt to ward off Dracula.

The principal men in the play are supposed to look equally alike, but in this production they do not. Josef Sommer's Ezra is properly calcified, Jeffrey DeMunn's Captain Brant has eyes that burn, and Bruce Davison is strangely blond but otherwise convincing as the mama's boy who is turned into a cynic and murderer. Each is fine on his own terms, but the three do not look or speak as if they possibly could be related.

In an effort to cut out some of the bunk, the producers at WNET in New York have drastically reduced O'Neill's chorus of townspeople to one old caretaker. This makes the dramaturgy more economical, but it also takes away some of the play's social context and makes it even more of a claustrophobic horror story.

Some of the scenes that tried to open up the play to the outside world in the first episode were awkwardly shot, but these attempts improve through episodes two and three (episodes four and five were not available for preview). And director Nick Havinga has found some starkly expressionistic angles in the old Greek revival mansion where most of the play was shot. Maurice Jarre has contributed an exotically portentous score.

Though most of O'Neill's life was full of gloom and doom, he did snap out of it for two weeks to write "Ah, Wilderness!" The PBS series will conclude on Jan. 24 with a rerun of an earlier PBS "Ah, Wilderness!"

In the meantime, a glowing production of "Ah, Wilderness!" is at Arena Stage, and it establishes that O'Neill's comedy-regarded by him and others as an escapist fantasy-actually measures the everyday lives of people much more profoundly than "Mourning Becomes Electra can.