General manager DeBoskey’s got a tall order to fill to keep Jazz 88.3 in the air.

“We have a diverse audience.” Mark DeBoskey is the general manager of KSDS Jazz 88.3 FM at City College. “We have the traditional jazz listeners who are 55-plus and remember the golden age of jazz.”

Plenty of music lovers in the 35-to-55 age group, too. But the straight-ahead jazz that the campus station broadcasts daily also has a much younger and far less obvious fan base.

“There are much younger people out late at night in our local jazz clubs and in jazz clubs around the country.”

And even though he says younger ears are less inclined to depend on conventional radio as their source, he’d still like to win them over to Jazz 88.3. But, first, he has to keep the station on the air.

DeBoskey tells the Reader that the radio station stands a good chance of losing its second-largest source of funding: the Corporation for Public Broadcasting. The money comes in the form of a community service grant and is good for 18 percent (about $145,000) of the station’s income. A re-jiggering of the census data is to blame.

Award of a community service grant is based on evidence of community support, DeBoskey says, as measured by either audience size or by income generated within the community.

“In other words, they look at the level of public involvement and they say, ‘If you’re that good, then we’ll support you.’”

But based on the 2010 census, the CPB increased the basis for arts support in San Diego by 62 percent in 2011.

“I called and asked about the increase. San Diego’s population had only increased by 10 percent since the last basis was established, utilizing 2000 census data.”

Hard news: “I was told that they were correcting an error made in their numbers from that census, and that the 62 percent increase would stand.”

The CPB gave KSDS two years to meet the new financial hurdle by “increasing either our revenue or audience by what turned out to be about double in audience size, or $120,000 in revenue.”

Failure to achieve either of those goals, he says, would result in KSDS being eliminated from the grant program.

“A loss of 18 percent of our revenue would be crippling to this radio station.”

Nearly half of the college station’s funding, he says, comes from listener donations and memberships. In coming days the station will go back to that well in an attempt to make up the difference. Will Jazz 88.3 make the new money goal?

“It’s going to be a horse race. We’re tracking very well, but I’m predicting we’re going to fall a little short.”

For more information or to pledge support, visit jazz88.org.