[Amps] SB-220 Exciter Foldback

[pmihnovets]

            I recently have been re-furbishing a SB-220.  It has the Harbach
rectifier board mod and also the Somis parasitic mod. Grids are grounded
directly to chasis with copper.  The problem I have been experiencing is
that my Alinco DX 70 is folding back power after running full power output.
( approx.) 600 watts in the cw/tune position.  It also will fold back in SSB
position.

 

I have tuned the input slug using a antenna analyzer.  I was coached in
tuning the slug by grounding the cathode using two 100 ohm resistors and
pressing the TR relay in manually.  I was able to get the slug tuned on 80
at 1.5:1.  but still having the issue with the exciter fold-back. 

 

Is exciter driving the amp to hard with 100 watts??

 

Any help would be appreciated.