Change is coming to the giant red pickle fork.

Sutro Tower, the three-pronged TV broadcasting tower celebrating its 45th birthday, is not about to get any less ugly, however.

What it’s going to get is a half dozen new state-of-the-art TV broadcast antennas that will make it even easier for the growing ranks of tightwad television junkies to cut the cord and ditch their cable bills.

It’s Sutro Tower that enables that wonderful and cheap invention called rabbit ears to work. A growing number of TV watchers — about 1 in 5 — receive their signals via antennas for free, over the air, old school. This year, subscriber cable bills increased as much as $10 a month, persuading more and more people to cut the cord.

The antenna installation will happen in the coming months, way up at the top of the 977-foot high tower whose summit is the highest point in San Francisco. The new Salesforce Tower, a few feet taller, took away top honors from Sutro for tallest structure in town. But Sutro Tower sits atop Clarendon Heights, so it tops out at 1,811 feet above sea level, well above the Financial District skyline.

The handful of folks who work at Sutro Tower, behind high barbed wire fences, are plenty excited about the new antennas, if not about the actual TV programming, which is not expected to get any better when the new equipment is up and running. The infomercials will remain the informercials and Jerry Springer will remain Jerry Springer. The antenna people say programs aren’t their department.

“Our business is to supply the garden hose,” said tower engineer Marty Acuff, standing on a catwalk in the middle of thin air. “What you squirt through it is your business.”

The barbed wire is impartial. It protects the tower from saboteurs, from vandals and from disgruntled viewers.

The renovations at Sutro Tower are part of an ongoing FCC-approved switcheroo. Another swath of bandwidths assigned to TV broadcasters were taken away and auctioned off last year to mobile phone companies in a $20 billion deal, the proceeds of which get split between the TV stations and the U.S. Treasury. This time, the UHF television dial — which used to go from channel 14 to channel 83, will shrink to it narrowest ever. After the switchover is complete, the UHF dial will end at channel 37.

Sutro Tower, however, will still look like Sutro Tower. And the poor tower will likely keep getting dissed.

Earlier this year, Hollywood location scouts dropped by for a visit, to see if Sutro Tower would be suitable for a backdrop in an Ant-man movie. After their tour, the Hollywood folks told the Sutro Tower folks they’d be in touch.

They weren’t.

Such slights began shortly after the tower was built, to considerable controversy, in the 1970s. The idea was to improve reception by moving most of the broadcast antennas from San Bruno Mountain. Reception got sharper, along with the insults.

“I keep waiting for it to stalk down the hill and attack the Golden Gate Bridge,” the great Herb Caen once wrote in these pages.

Sutro employees who labor in the shadow of the giant Tinkertoy don’t seem to care. They just do what the consortium of TV and radio broadcasters who actually own the tower tell them to. Perhaps the best thing about working on Sutro Tower is that you can’t really see Sutro Tower while you’re working on it.

“It’s the tower everyone loves to hate,” agreed chief operating officer Eric Dausman, with a big smile. “It’s the big, ugly neighbor.”

Like many 45-year-olds, Sutro Tower is doing its best to cover its blemishes. Dausman said he no longer bothers to repaint the iconic red parts of the tower’s three legs. Blasting and chipping off old paint would shower paint chips onto nearby streets and make the tower’s neighbors sore.

Besides, the tower was originally painted red to make it more visible to pilots. But new warning lights on the tower and a change in aviation rules mean that the tower need no longer be red. One day, Dausman said, the entire structure will fade to a uniform gray.

Every day, inspectors scramble up the tower and look for “corrosion” which, in English, means “rust.” The tower’s 10,000 bolts and 30,000 fasteners are replaced or repainted when the brown stuff pokes through the red and gray paint. Dausman said his crews have replaced about 3,000 bolts over the past six years.

“A bolt has a 40-year life span,” Dausman said, while a pair of bolt inspectors were hauled aloft in a basket dangling from a crane to look for more bad ones.

Inspector Tanner Lemann, one of the bold and brave danglers, said the most important part of his job was to “respect the height and pay attention to what you’re doing.” As for rust, he said, “you can’t find all of it.”

Sutro Tower was showing its age in other ways. One leg of the 45-year-old tower contains a tiny 45-year-old elevator, to allow access to the topmost prongs of the pickle fork. And 45-year-old elevators break down, which is what the Sutro Tower elevator did when a Chronicle reporter was inside of it at the tower’s summit, waiting to return to planet Earth after a brief tour.

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The button on the control panel was pushed. The elevator descended 5 feet, then stopped. It wouldn’t budge.

Over the walkie-talkie, engineer Acuff told the reporter to slam the elevator’s sliding door and “jiggle and wiggle” the safety catch. This the reporter did. The elevator descended another 5 feet, and stopped again. At the moment, the reporter was the highest person in the city and county of San Francisco, and not getting any lower.

“It’s not moving,” the reporter said over the walkie-talkie, gazing out through the gaps in the elevator cabin at the glorious sights of San Francisco far below and wondering if he would ever rejoin them.

“Slam the door again,” said Acuff, from the ground.

There were two more rounds of slamming, jiggling and wiggling, to no avail. It was beginning to look as if The Chronicle would be opening a new bureau at 1,811 feet above sea level.

But the fifth round of slamming, jiggling and wiggling was the charm. The elevator, with reluctance, began inching downward. After eight minutes, it spat out the reporter on terra firma.

On the wall of the elevator cabin hung the state safety inspection certificate. All elevators are required to have them.

“Date of inspection 7/24/2015,” the certificate said. “Date permit expires 7/24/2016.”

Steve Rubenstein is a San Francisco Chronicle staff writer. Email: srubenstein@sfchronicle.com