Use an inexpensive digital voltmeter to measure the battery voltage while the engine is running. It must be between 13.75 and 14.75 volts. If it is low, the generator is not recharging the battery while you drive. As the battery slowly discharges, the radio will start to act up along with all the other computers on the car. The clue is the need for a jump-start. Loose, dirty, or corroded battery cables and connections can do that too although usually you won't have symptoms while the engine is running. They cause most trouble when trying to start the engine.
Tuesday, June 7th, 2011 AT 8:24 PM