A whistle that could have a revolutionary impact on the NFL's use of instant replay was secretly tested at selected games throughout the 1988 season, including the playoffs, but not in Super Bowl XXIII.

The whistle activates an electronic impulse that prints a black strip across the top of a television feed, pinpointing when the whistle sounded and which official was responsible.The system has the potential to eliminate one of instant replay's biggest headaches: determining when a whistle is blown in relation to a fumble.

Tex Schramm, president and general manager of the Dallas Cowboys, said the system was working well enough in December that he appealed to NFL Commissioner Pete Rozelle to use it - not just test it - during the playoffs, including the Super Bowl. Schramm said Rozelle rejected the idea. "He felt there should be a full discussion by the league's owners before it is used officially," Schramm said.

"But as far as I know, it's ready to go. They've been working on perfecting it all year and, at the end of the season, it was working very well. I'd like to see it on an official basis for next season."

Schramm is chairman of the NFL's Competition Committee, which examines all rules changes. The committee will meet in early March and receive a report on the whistle experiment before presenting a recommendation to the league's 28 owners, who will conduct their annual meeting March 20-24 in Palm Desert, Calif.

Early in the 1988 season, there were technical problems in transmitting the whistle's signal, Schramm said. But, he added, "We ironed them out and, since then, I haven't received any negative reports on it."

There could be a patent dispute over the whistle. The concept was first presented to owners at their meeting in March in Phoenix, by James Brawner, a free-lance San Jose television producer, who gave the NFL a prototype whistle and a five-minute videotape explaining how it worked.

Brawner's whistle was hand-held with a trigger that activated the sound. It ran into trouble when Art McNally, the NFL's supervisor of officials, said his men would not carry the devices around the field. They insisted on using mouth whistles.

As a result, Rozelle put Jay Gerber, vice president for special projects for NFL Films, to work developing a mouth whistle that would perform the same function as Brawner's hand-held whistle.

When Brawner found out about Gerber's work two months ago, he bristled. "What they're doing potentially violates my patent," he said. Gerber, contacted at that time, had little to say: "You're putting me in an awkward spot. This isn't a subject I can be candid about."

Brawner was interviewed again Thursday. "It's news to me they were testing during regular-season games," he said. "I met with Don Weiss (NFL executive director) on December 10, and he told me they hadn't done any experimenting with it to that point."

Weiss said Friday: "I never told him we weren't experimenting with it. I told him we were working with a system developed by NFL Films to see if marks could be made on tapes. In most cases, this took place in a separate room, not in the same room where the replay referee was working."

Brawner also reported that Weiss had assured him that if instant replay is continued into 1989, and if his invention or some form of it is used, the NFL would compensate him for the idea.

"Based on this latest development, I do have to admit I have my suspicions, though," said Brawner. He said he is still waiting for a $12,000 check to cover his expenses in producing the videotape, "which they asked for," he added. "They just spent $700,000 on a Super Bowl party in Miami. You'd think they could give me my $12,000."

Weiss said the NFL is not dragging its feet on the $12,000 payment. "We have his letter, and I'm waiting for the league to act on it," he said.

The whistle development comes at a time when instant replay is under siege for the third straight off-season.

"If the vote were tomorrow, without any lobbying, it would go down to defeat by about 14 to 14, far short of the three-fourths (21 votes) needed to pass it," said Art Modell, owner of the Browns.

Owners continue to be angered by long delays and controversial decisions by replay officials.

"I don't feel any differently," said New York Giants General Manager George Young. "The game belongs on the field, not in the TV booth, and we'll vote against this thing into the 21st century."

The Giants were joined by Buffalo, Phoenix, Kansas City and Cincinnati in voting no last year. There are no indications any of those teams have switched positions. Pittsburgh is now aligned with the anti-replay forces, and the San Francisco 49ers and Minnesota Vikings also have indicated they may vote no.

In fact, Modell said he was going to vote no because of a call - what appeared to be a lateral by the Houston Oilers was ruled as an incomplete pass - that went against the Browns in a 24-23 loss to Houston in AFC playoffs.

"We were victimized by the system. I was so angry, I was going to vote against it when it came up in March." But, he added, "instant replay also reversed an obvious error in the Super Bowl."

"Let's face it," he said. "It's here to stay because of another reason. The fans want it. It enhances their viewing pleasure. That TV spot, `You Make The Call' ... it's very effective advertising. The delays are bothersome, I agree. But I'm going to make a pitch for it at the owners' meeting."

Instant replay has been in use by the NFL for three seasons, requiring an annual vote.