Underwriting is possible, but the station is going to need to provide a service that isn't provided for the area (= listeners). The problem is that most formats that would bring in listeners has been taken.
I run WEEM in Pendleton and we have underwriters, family donors and more that bring in a nice amount of money, but not nearly enough to fund 2 salaries, utilities, etc. The school will have to make a commitment to the station and broadcast program in order to keep it part of the education of the school district. If you have a dedicated alumni base and current student load, let the school corporation know you want the program continued, and maybe it will survive.
WEEM has live or voicetracked DJ's 24 hours a day/ 7 days a week. Live newscasts from 8am to 4pm, we do the school announcements, broadcast between 75 and 100 Pendleton Heights sports events, have invested in promotions materials (including a very nice EZUp tent with our logo), go to many community events, started a blog and beginning to touch video in order to teach convergence, and have ongoing conversations with other radio/tv teachers and professionals in central Indiana. We pride ourselves on running the station like I did in a commercial station environment, with on-air responsibilities tiered to focus better shifts on better students while giving an opportunity for all.
See iasbonline.org for contacts of other high school radio station in Indiana. For some reason, Greenfield hasn't been a part of IASB for at least the last 10 years.
One station that has made a significant amount of money from underwriters is the new station at Rushville High. They may have some ideas.
I would avoid time-shares at all cost, it limits your ownership of the frequency.
Jered Petrey
WEEM General Manager