10-29-2015, 07:44 PM
(10-29-2015, 07:31 PM)radiohenry Wrote: 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
Henry, I did not use electrolytic's. I used the original values and they were all new Metalized Polyester rated at 630V. The filter uses two 1uf, one 1.5uf and one .13uf (1-.1 paralled with 1-.033) The 1.5uf is the AF supply filter and yes it has been changed twice. I would never use electrolytic"s to rebuild a capacitor that originally used paper type.Tubesforme