
If you are using the YK-AD2003 power supply, cable shoes on the power cable from the power supply to the PA3 will secure the wires better than just fastening them. The screw terminals are approx. 5mm.
To connect HV input from the power supply to the PA3, I used Bulgin PX0646 Farnell 313970 and Bulgin PX0429, Farnell part# 313993.