From lists@oceanbeach.com Tue Dec 04 16:46:46 2012
Subject:Re: Transpose a B3?

Yep. The Hammond is pretty forgiving of fluctuations in voltage, but not frequency. I have first-hand experience of when this goes wrong. My band used to play an outdoor festival in Mexico, and the first time I brought the Hammond down there it was almost a half-step flat. I did not find out until soundcheck. I could have had the whole band tune down, but I also had a Rhodes with me, so I'd be forced to choose between the two. Fortunately, the generator was one of those big diesel jobsite things on its own trailer, and the control panel had displays for both output voltage and output frequency. To change the frequency you had to reach into the engine bay with a screwdriver and adjust a bolt on the throttle. A friend of the band stayed near the generator all weekend, tweaking it occasionally as needed.

After that happened I bought one of these: http://www.trekii.com/#EXPORT
The Trek II SC-60D-2 is a separate power supply for the synchronous motor, and it uses a quartz reference to generate a perfect 60.000 Hz line frequency. This box is a must have if you ever play outdoor festivals with a Hammond, because you really have no idea what kind of line current you'll be presented with.