Now and then, Earl Hamner, the man who created ''The Waltons,'' bicycles over to the old Burbank Studios set to visit the old Walton homestead. ''Once it was a Malaysian farmhouse when they were shooting 'Bring 'Em Back Alive' there. This past week,'' he says sadly, ''I found it had been turned into the 'Dukes of Hazzard' orphans' home.''
Then he perks up just a bit. ''Maybe we should try to save 'Boone' by having the family move into the old Walton house,'' he jokes.
Earl Hamner is in town to save his latest creation, ''Boone'' (NBC, Mondays, 8-9 p.m.), which has had the misfortune to be scheduled against ''Scarecrow and Mrs. King'' on CBS, one of the few successful new series of the season. ''Scarecrow'' stars former ''Charlie's Angel'' Kate Jackson. ''It's not very angelic of dear Kate to do me in,'' Mr. Hamner protests mildly.
Actually, Hamner is a mild and gentle man in almost everything he does. One feels one could trust him to handle almost anything tastefully, as evidenced by the way he led his greatest success, ''The Waltons,'' through the potential quagmire of action-oriented commercial television. But he is beginning to have some doubts.
''Should I have made 'Boone' a bit harder-edged?'' he asks himself during a recent interview. ''When I finished with 'The Waltons' I told myself I mustn't dwell on the past, and I put in 'Boone' jail episodes and other things at which John Boy Walton would have fainted. But maybe I didn't go tough enough. But, then again, I really don't think that's the answer. People simply have not sampled 'Boone' yet. Maybe it's the promotion.''
Does Hamner believe the day of the softer-edge TV series is over?
''I would hope not, because if that's the case I have to get out.''
But isn't his production company responsible for ''Falcon Crest''? That certainly is not a soft-edge comedy.
''Oh, that,'' he says, seeming to be just a bit embarrassed. ''I think it's a lot of fun, a kind of contract between us and the audience. You want outrageous, wait till you see what we've got in store for you next. It's a game. It's a contract. It's campy. But it's not hard-edge comic strip like some of the other nighttime soaps. Our people have some dimension. I think that Angela Channing (the domineering matriarch of ''Falcon Crest'') is the Walton of her time, trying to protect her turf, her piece of land that represents an established way of life.''
''Boone'' is a drama set in the early 1950s against the backdrop of post-World War II Nashville. Boone Sawyer is a young singer from a blue-collar family. Tom Byrd, who plays Boone, sings several songs - country-western and rockabilly mostly - in each show. There's a bit of the Elvis in him.
As Hamner himself keeps saying, it is true that ''Boone'' is one of the few new shows the whole family can watch together. It's soft-edge but not so soft-edged that it will put action-oriented fans to sleep. And above all, each episode seems to maintain a consistently high standard of morality.
''It really is one of the few shows that the whole family can watch, and it is also one of the few shows in which there is a mom and a pop and a whole family. TV needs that kind of show. I watched 'That's Incredible' (ABC) the other day, which airs opposite us, and I saw a man eating live crabs. Really, is that what entertainment on TV is coming to? Are people attracted only to garishness and glitter? 'Boone' reflects what a lot of blue-collar families go through. The family relations are not always perfect, but somehow the family works it out together.''
He sighs. ''I tell you, 'Boone' is as good as I can give. I don't understand why it stays so low in the ratings.'' Hamner says, ''NBC is talking about switching the time slot . . . maybe that will help.''
Although current episodes occur in 1953, Hamner says, ''I intend to hang in there for 10 years and get the series into the 1960s if I have to drag people off the streets to the TV set. I simply cannot let this one die. (Otherwise) a whole genre of family entertainment has disappeared from American television.
''Why can't we get more people to sample the show? Won't you tell your people more about it?''
''Boone'' . . . Mondays . . . NBC . . . 8 p.m. . . . try it.
Chat with Nancy Marchand
Agatha Christie stories are usually so filled with clues that some actors find plays based on her work difficult to act in, since they are afraid to improvise a simple gesture for fear that gesture will be interpreted by audiences as a clue.
But Nancy Marchand - the Mrs. Pynchon in ''Lou Grant'' - solved that problem in her role in ''Sparkling Cyanide'' (Saturday, CBS, 9-11 p.m.).
''All through the shooting I had to ask myself, 'Should I react as somebody who is innocent or as somebody who is guilty.' And I decided it was much more fun to put on a guilty face.'' You'll have to see the film for the correct answer, however.
I won't bother to fill you in on the plot - you wouldn't believe it anyway. But this Tinseltown-oriented tale, starring Anthony Andrews of ''Brideshead Revisited'' fame), Deborah Raffin (''Running Out''), and Nancy Marchand, has been updated (to present day) and relocated (to Hollywood) where somebody is lacing the champagne with cyanide.
''Sparkling Cyanide,'' produced by Stan Margulies (''Thorn Birds'') and directed by Robert Lewis with some flair, is a sparkling bit of fluff in which all of the actors seem to be enjoying themselves immensely as they sprinkle clues around like Johnny Appleseed sowing the soil. It can serve as amusing light entertainment . . . if you have nothing better to do on Saturday night. But somehow, Agatha reads better than she plays.
Does Miss Marchand miss ''Lou Grant,'' in which she played her most recognized role?
''I don't miss 'Lou Grant,' because I have enjoyed what I have been doing since then. But I do think about it a lot. It was a great pleasure. My character was fun to do, based as it was on all the grande dames of journalism.''
Was it politics that caused the cancellation?
She nods. ''It was. But not what so many people think. Of course, Ed Asner's personal politics didn't help at the end. But don't forget, it was the time of the beginning of the fundamentalist drive, when they were complaining about the so-called liberal outlook of many shows. We were doing some very relevant things. And when the sponsors started to make waves . . . well, that was the end.''
Does it mean that others will be afraid to handle relevant subject matter?
''No. A few shows are still doing it. But there's so much macho violence and soap opera garbage that I almost never watch television. . . .
''Except, of course, for nice, civilized and sophisticated little murder entertainments like 'Sparkling Cyanide.' ''