I had the MRC Tech II throttle (before I gutted it using the case for a custom-built TAT IV throttle. I vaguely recall that the original speed-control pot had a tap on it, about a third through its rotation. I think that was used for injecting pulses on the lower third of the throttle (and then straight unfiltered DC for the rest of the throttle knob travel). I think it was an "automatic pulse injection", but my memory is fuzzy on that - I might be confusing it with another throttle.
