[morzh]

Well, whatever the procedure, I went for the graft.
I am not that skilled to take off the whole cone and put it back.

The damage to the cone of the working speaker was clearly done by a mouse, the teethmarks and the shape of it. Stopped short of chewing on the coil itself.

I used a very sharp blade, cut a sector, used a fabric glue I bought yesterday at Michaels, and glued it on top of the old one. Tomorrow will see.

Also the transfomer base is a wrong size (they used different speakers on several modifications) so tomorrow I will try to put it in and will solder the speaker in its place.

I think DC resistance of 22K instead of 400 Ohm does not improve the output quality, so I expect some degree of improvement.


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The Pentagrid 6A7.

This is what old age does to you.
I had a perfectly fine pentagrid all along to test this radio with - my 18 uses it, and I know it is good. But I finished the 18 and fully forgot of what's inside.
Now looking at the schematic I see that 38/39 series and 18 have a huge portion of the circuitry nearly identical to reach other.
Oh well, I needed the new one anyway, but at least could satisfy my curiosity three days earlier