.........I think for a 1k series resistor anything between 10k and 100k should work fine.
-- The Aussie Shield: breakout all 28 pins to quick-connect terminals
I disagree. If the 1k resistor is changed to 100k and the other one is 47k, then the current from the output is 34 uA causing only 1.6 V to gate. With 1k, the current is 0.1 mA and gate voltage 4,9 V. Much better.