Your 2nd picture indicates using a 5.6v Zener diode, instead of the 1N4148, also, the order of Diode/Resistor is now Resistor on bottom, where the home made EKL is Diode on bottom. With the Resistor on top, it more isolates the Zener from the RF voltage being applied.
Oops, I looked again, the EKL has the 1N4148 cathode (bar end) going to the + side not the Anode (non bar side) going to ground.
Thanks. I have swap diode with 390R resistor, and the gate voltage up to 1.4v, but the output power is the same, 3.8w.