[Elecraft] Low Power Out

[Ed K1EP]

I was operating on 80M this evening and noticed that I wasn't getting 
full power out.  Sometimes if I transmitted a carrier, I would get 
120W and then it would jump down to 80W.  I don't believe it is RF 
feedback, bad antenna, etc.  What I did notice is that in the TX GN 
HP menu setting for each band, I get a number, such as 24 or 15.  But 
on 80M (where the problem is), I get a setting of "Pr80 24".  I 
haven't seen the indication "Pr80" before on the TX GN HP menu.  What 
does that mean?   I am using the new beta 2.76.