Here's the deal: it doesn't matter if you are a commercial station or a non-commercial station, you have to have the financial support from the listener to have a successful station. If it is not successful and you can get your university or some other entity to foot part of the expenses, great, but do not count on those dollars because they never last. Simply put, if it's not working and can't stand on it's own, then change things before it all comes crashing down.
Overall public radio is doing better than it ever has. They are achieving exceptional ratios on donating listeners versus total listeners. There are creative incentives that are working to back up these numbers. In fact listener membership figures are higher than ever. Underwriting recruitment has become more professional and looking at ratings, public radio is a contender in most every market. Sure the smallest public stations will never have enough to pay the bills simply because the population is too small to do so.
I'm supposing this will lead to the usual scare tactic that if Congress cuts funding public radio stations will all go away and all the programming will too. Educate yourself. Look at annual 990s from these stations. Do you realize federal funds account for about 5-6% of a station budget and the biggest moaners about this are stations doing millions each year while the little independent has never received a cent from the feds and never has an issue. Nobody will go away and while any cut will hurt, in reality it will be a mere bump in the road. If you can't find a way to bring in 5% or 6% more, I want your salary and job because you haven't a clue about running an organization or business.