[radiohenry]

Hi Tubesforme,
    I would like to suggest reviewing the rebuild of the filter block. I suspect there in lies the problem. Certainly it can be rebuilt using electrolytics  however the original did not have electrolytics or if I recall correctly .22uf.
  The filter block used two 1.0 uf , one 1.5 uf and one .13uf and if I read this correctly pin #1 was the common ground.
  On the last 20 that I rebuilt the filter block I removed the old components and using non electrolytics wired all the components inside the old can to the terminals indicated on the filter block diagram . When I finished replacing all the other caps and resistors it played like a new radio.
   Just my thoughts after I was fortunate to have an excellent experience in the rebuild of a model 20.
                                                    Good luck,
                                                             Henry