[Gonset] Need G-76 help...

[Fabio Liberatori]

     Hello Gonset lovers,
                         now I really need a little help for my 
(beautiful, but fussy) G-76...

After a long, complete restoration and alignment, the radio works, I think at
90 % : 40 W out, fair modulation, good reception.

BUT : in 80 meters no plate dip, nothing to do, I have replaced the 
RF choke with two more ones, changed 3 different final tubes, no 
luck...

Any experience out there with such a problem ??

Another question : at low power the modulation is very positive, at 
high power it's slightly negative : is that normal ??

Well, any idea, suggestion, invention or hypothesis will be GREATRLY 
appreciated, I want this jewel back on 80 meters rag-chewing...!!

     Thanks and 73,
     Fabio, I0LBE