[Elecraft] PTT keying a KXPA100 with a K2

[Luc Favre]

Hi,
I own a QRP-K2 with the KIO2 installed.
I want to PTT key a KXPA100 (not KPA100).
May I connect Pin9 from KIO2 (8V in receive mode and 0V in transmit 
mode) directly with the PTT-IN connector on the KXPA100 (5V receive, 0 V 
transmit) ? Maybe with a diode (cathode KIO2, anode KXPA100) ?
Thank you for advice
73
Luc F6HJO/HB9ABB