I can confirm that the above fix (Mr. Kang) works :-)
Yesterday i changed the value of R65 to 4K7 and the value of R63 to 10 Ohm.
I used 1206 components (desolderd from scrap prints).
I now have, on normal voice volume, 10 watt's out on 20m.
RV1 is turned counter clockwise for about 75%.
I use a Baofeng microphone.
73 's André PA3EIV