That makes no sense, you can't have a 300mAh transformer, do you mean a 300mA transformer?
With a 300mA transformer the maximum current you can safely draw from the regulator is 212mA; how much current does your AM radio draw?
I doubt they are 23,000:mu:F capacitrtors; it isn't a standard value.
Anyway 22,000:mu:F is pretty excessive for only 212mA, you only really need 2,200:mu:F I would 3,300:mu:F to be on the safe side. Even so using larger capacitors is unlikely to do any harm so I don't see the problem.