I have this problem, but it is not due to the antenna coax cable coming apart. A few times in the past I have had to reattach the cable ends, until I finally taped them together with several wrappings of electrical tape.
This time I looked, expecting to find the tape had failed, but the cable was intact. I checked the end at the antenna, and it is secure. Is there a signal booster in the radio? Does anyone know of another cause for the problem?