By ROY FURCHGOTT

HEN it comes to the futuristic, nostalgia can be a complicated business.

Take the collectors who have made a cult item of what was once the most futuristic watch in the universe, the Bulova Accutron. Introduced in 1961, it was the first successful transistorized watch, far more accurate than any other watch then on the market and a major advance in timekeeping technology.

Worn by test pilots and used in NASA vehicles, the Accutron dripped with glamour. For a few hundred dollars, anyone could wear this emblem of the space age and the new worlds being opened by technology.

Bulova recently sought to cash in on the cachet of the most famous of the original Accutrons, the Spaceview, by issuing a Spaceview 21 for the 21st century (suggested price, $950 to $995, depending on choice of metal). It has a see-through face like the original, so that the watch's guts can be viewed.

It also includes a technological advancement: a quartz movement that runs perpetually through a self-charging battery. Such a feature might have seemed likely to appeal to the same technophiles that loved the original. But that's where Bulova lost collectors like Martin Marcus, a retired machinist and Accutron repairman in Marblehead, Mass.

Having a watch that makes no noise holds little interest, he said. For Mr. Marcus, the hum of the original watch was crucial to its attraction. "If you put it over a hollow part of the dresser, you can hear it ringing throughout the room," he said.

The original Accutron's electronic movement relied on a miniature tuning fork. Two tiny electric coils were placed on either side, creating an electrical field that caused the fork to vibrate. The vibration moved a ratchet that pushed the watch hands forward. The second hand advanced in 360 increments per second, a smooth motion in comparison with the nine leaps per second for the finest mechanical watches. Instead of a tick-tick-tick sound, there was the continuous tuning fork tone.

"People ask what is it, I say, `It's a hummer,' " said George Neville, a retired detective in Missoula, Mont., who bought his 1966 Accutron Spaceview in a PX in Da Nang while serving in Vietnam with the Marines. He holds it up so that people can hear the distinctive high-pitched Accutron whine.

So while the new limited edition Spaceview 21 sells on eBay for $200 less than its list price, the original Accutrons are so prized that unscrupulous repairmen manufacture counterfeit versions.

Mr. Marcus said he bought a stainless steel Spaceview in 1964 to lift his spirits in the aftermath of the assassination of John F. Kennedy. For him, the appeal lay in wearing a scientific instrument. "I was fascinated with technology," he said. "Every other day there was a new jet in the paper, and anything to do with that was of interest."

At the dawn of the space age, the watch's association with test pilots, who were given free Accutrons, intrigued buyers. "They did a great promotional job," said Daniel Nied, director of the School of Horology run by the National Association of Watch and Clock Collectors. "When it was introduced was perfect timing. They supported the product and gave away the right models to the right people."

The notion of what timepiece was most significant to NASA's space program is the basis of a rivalry between Accutron owners and Omega Speedmaster owners.

The Speedmaster was endorsed by NASA in August 1965 and became the official astronaut's watch. The Accutron was used as a timer in satellites and scientific devices and on the instrument panels of many capsules that traveled into space.

Buzz Aldrin, the second man to set foot on the moon and now a spokesman for Bulova, contends that the Accutron has a legitimate claim to space. The Accutron was used in the displays of devices that were more crucial than a wristwatch, he said. Astronauts essentially only wore watches as a backup for timers on the spacecraft, he said.

But as well loved as the original Accutron is, time is running out for collectors. Parts are scarce, repairmen few. "In a few years," said Mitchell Feig, a part-time Accutron repairman in Coral Springs. Fla., "you won't be able to get one repaired, no matter how much you are willing to pay."

Bulova stopped making the tuning fork for the Accutron in 1976 but set aside parts for an estimated 15 years of service.

When owners of the original Accutron 214 send Bulova a watch with a broken coil, they are told that the watch cannot be repaired. (Owners of the later, less sought-after 218 model can have a quartz movement installed.) "We are completely out of the coils, forks and index wheel assemblies," said Bob Weber, a vice president for operations at the Bulova Corporation, based in Woodside, Queens.

Yet some callers seem convinced that Bulova has a secret cache of parts, Mr. Weber said. If there is one attribute uniting Accutron owners, he added, it is their tenacious attachment to the watch.

Not that owners don't have cause for worry, with some of the easier-to-find Accutron models being altered and sold as genuine Spaceviews. Converting a watch into what looks like a Spaceview may entail little more than removing the dial and painting hash marks on the crystal. Mr. Feig, the part-time repairman in Florida, estimates that 80 percent of the so-called Spaceviews in use are actually converted.

LaHugh Bankston, an Accutron collector who is the registrar at the University of the District of Columbia, says that hunting parts is part of the fun of ownership. Mr. Bankston, who received an Accutron 214 for college graduation in 1968, now trolls eBay and old watch shops for bargains. "I got lucky once," he said. "A guy had about 25 coils I purchased. I found some guys with index wheels that sold them to me at the price they paid when they bought them."

Why go to such trouble when there are more accurate watches on the market, as well as collectible mechanical watches that will never die? Mr. Marcus, the repairman in Marblehead, Mass., compared the phenomenon to baby boomers' restoring cars that thrilled them as teenagers.

"It's a connection with our youth," he said. "The watch is better than a car. The car is out in the garage. The watch is in front of your face all of the time."