The schematic is now updated to version 1.4. As well as rationalising the resistor values, I have changed C22 from 100nF to 47uF. This is the call button de-bounce capacitor and some builders were finding that there was a audible bump on the line when the call button was pressed hence the value change. The PCB has been updated to allow for an electrolytic cap at C22. The new zip file contains all the new gerbers, schematic, assembly diagram and parts list. PLEASE NOTE: none of these changes have been tested but I am confident they will work OK. The files can be found in the next post.