[drakelist] Low output from L-4B?

[AirRadio]

I have noticed recently that my L-4B only seems to be putting out 800 to 1000w 
to the antenna on SSB setting and around 600w on tune key down, is this correct 
or are the 3-500z's getting a bit old, I thought I was getting more than that 
sometime ago but cannot remember. 73 Max