Sergie had trouble getting reception on his favorite radio station. He thought for a long time and concluded that the following were variables in radio reception. I would test antenna direction first. This is the easiest. Then I would experiment with antenna length.
Tired batteries are sometimes the cause.
Nighttime radio has less interference from the sun, but he can't control the sun, nor can he control the strength of signal from the radio station or mountains in the way. He could move the radio around the house, but he is probably more comfortable in one place than in others. Three people go trapping on their own traplines. The third person barely managed to pay his fuel bill. There used to be many moose in the country.