I am getting ready to install Railsounds in a second EMD F-3 A unit. Would the prototype prime movers ramp up in sync or would they be somewhat out of sync when run together?

Pete

The real F3s (like all first generation EMDs) had 8 different engine rpms, one for each of the 8 throttle notches. When the engineer advanced or decreased the throttle handle position all trailing F3s would respond at once. After each unit's prime mover settled at the new rpm for the new throttle position they would each be running at _approximately_ the same rpm, very close but of course not exact so they did produce a beat.

Wyhog

Thank you. This helps a lot on how I will handle this.

Pete

Does this mean that newer locos have a different system without notches etc??

Sort of, yes. Many GE "modern" units have engine speed programs that don't exactly match the 1 thru 8 throttle notches, i.e. the engine may "do its own thing".

It isn't just GE's. GE's been doing that since the C30-7 era but EMD's do their own thing as well now days. SD70MACs try to anticipate what the engineer is going to do. Drives me nuts.

Wyhog