[NJARC] Radio Repair Questions

[Grant Buford]

I've got a couple of questions.  My current project is a GE H116 console 
radio which  has a push-pull 6Y6's in the output stage.  I currently 
only have one replacement 6Y6 tube so I replaced the tube of the 
original pair that tested the worst.  The remaining 6Y6  read  in  the  
"?" range on my  tube tester (the other bairly moved the needle).  One 
of my questions is, is it ok to only replace one tube of  a push-pull 
pair?  I will probably change the other tube as soon as I get a 
replacement.  I've heard of  output tubes being sold in "matched pairs", 
what does this mean?  When I do get the other tube, is there something 
in the circuit I should check to make sure the tubes are operating properly?

Any words of wisdom would be appreciated. Thanks.
Grant Buford