Recently a woman hunting for a new condo told the realtor she had one nonnegotiable requirement: the unit had to have excellent reception of WJIB 740-AM. It took three months but she finally landed where she can hear it perfectly all day long.

Debra Block, Site Manager/Activities Director at the Kit Clark Senior Center, is a host of “Boston Seniors Count” which airs Sunday mornings on WJIB. She plays WJIB at the Fields Corner facility, noting “We have a big ethnic mix, but everybody here just loves the music!”

This Saturday many equally loyal fans of “The Memories Station” will be celebrating the 20th anniversary of perhaps the smallest station on the Boston AM dial, but one with enormous impact on myriads of devoted senior listeners.

WJIB’s daytime output power is 250 watts, reaching 3 million people inside Route 128. At night the station must power down to a mere 5 watts, reaching only about a million.

On August 4, Bob Bittner, who owns and virtually single-handedly runs WJIB and a sister station WJTO (AM-730) in Bath, Maine, will mark his two decades at the mic with a rare call-in request show featuring “the music we grew up with.”

Instead of current pop hits, WJIB (with its Adult Standards/Middle of the Road format) broadcasts chart-toppers of the past 10 decades. Many of these selections had greater worldwide sales than most of today’s digital downloads.

Listener-supported WJIB (“Easy as the Breeze”) offers what for many is the perfect background music for home, office or barbershop. There are no commercials and little interruption except station IDs , PSAs like the EnvironMinute, and Bittner’s occasional warnings like “Credit cards are like snapping turtles issued by snakes!”

While the former owners of WJIB played mostly “beautiful music” instrumentals, the 63-year-old former DJ now schedules 6 vocals for every instrumental, except from 12 midnight to 5 a.m., when the proportions are reversed. These soothing sounds, Bittner believes, helps people doze off especially “elderly folks who have medical conditions that keep them from sleeping. The nice sounds of WJIB at night create a splendid environment of peacefulness.”

Appreciated as the beddy-bye ballads are by insomniacs, the station is best known for its brassy Sunday noon to midnight “Big Bands and Crooners.”

The predominant tempo and mix varies with the time of day. Mornings feature peppy, get-up-and-get-busy ditties and the occasional song in another language. Afternoons have a lot of mellow guitar-backed tunes from the 60-80s.

Bittner personally sorted about 6,000 songs into one of 15 categories and his computers rotate all them at different intervals. Some come around every 4 days, and others only every 180 days. Bittner claims that about 50 percent of his playlist is no longer commercially available. Part of his collection comes from rare recordings fans have donated.

The station airs over a hundred years of music, ranging from waltzes and marches from the 1800’s to a few tunes from the 21st century. Just last Saturday, it followed “(That’s Why They Call Me) Shine” (1910) with “Perhaps, Love” (2010), a John Denver /Plàcido Domingo duet.

Not all listeners have walkers and wheelchairs. Younger fans have set up a Facebook page “Friends and Lovers of WJIB,” where they post their pictures, comments, even videos of songs played on the station. Indie composers keep it on for inspiration and sampling.

To contribute to the current annual fundraiser go to wjib440.com.