5kCSTQ Radio Problems

["L. Scott Oliver" <SOLIVER@gcwf.com>]

I have the standard 87 5kCSTQ radio (Rothenburg?) which has,
for no obvious reason, suddenly started displaying the following
symptoms: 1) The power antenna and rear speakers no longer
operate at all (though the fronts work fine); 2) the radio stops on
".0" frequencies (e.g., 99.0, 100.0, 101.0, etc.) and picks up a
hum.  I'm pretty sure I haven't disconnected anything related to it. 
Any ideas?  Is the radio toast?

TIA!

--Scott