PM Research Dynamo

[Rustkolector]

I am setting up the PM Research dynamo on a small gas engine model I have recently finished. I want to set it up for about 6-7.5 volts output. I saw a voltage vs. RPM output curve for this little dynamo somewhere on the internet, but now I can't find it. The PM Research associate that answers the phone was of no help. Can anyone point me to this output curve?
Jeff