Screen grid is connected to the plate.  Signal grid as usual.
Cathode is connected to the filament.
An 801 is the same as a VT-25/ type 10.  It will not
produce as much power out as a VT-25A, but if one is looking for
"big power," it's better to amplify it after the transmitter.  The
modulator circuit has only enough "juju" for moderate power out.

Here is the complete set, transmitter on 40 meters,
using a well-regulated B+ supply.  If the B+ supply is not
well-regulated, it will chirp like a bird.
https://youtu.be/MkA0W3MTM1I

This was several years ago.  We need to discuss something about
how the cathode is connected to the filament in a series-connected
filament configuration.   Some time soon.  Too tired right now (flu).

73 Dave S.

Does this connect all grids to the plate?

Also, is one of the tubes you have replaced, identical or similar to type 801 ?

-Hue Miller