Radio Problems

[Teenangel]

I have a 1983 280ZX that has a radio that's misbehaving. It will not remember presets after being turned off for an hour or so. I have also noticed that sometimes the antenna goes up when you turn the radio on and sometimes it does not. I have been gone for two weeks and went out to the garage and turned the radio on last night without starting the car and the antenna came right up as soon as turned the radio on. Although my battery voltage was in good shape (12.3v) I decided to top the battery off with a trickle charge overnight. This morning I go back out with a fully charged battery (12.6v) and tried it again and the radio came on to the AM band (no presets) but the antenna would not come up. The car had sat idle since the night before so I have no idea why that worked last evening and 12 hours later it didn't. Another thing I've noticed is that the radio does not come on automatically when I turn on the ignition like it once did. I now have to always push the button to turn it on after turning on the ignition. I can find no rhyme or reason for this. I have thought that it might be dirty connectors but then again I wonder if its just the radio. If anyone has any insight on this I would appreciate it.