Randy et al: Thanks guys. Last saturday we methodically went through the different combinations of AR-1 and PM 42 speed setting, trying to determine which setting resulted in the shortest stall. ( The AR-1 is downstream from the PM 42.)
The best result was the PM 42 set slow and the AR-1 set fastest. This produced NO stall when traversing the gap at SLOW loco speeds (yard speed). However, there is some delay at "road" speed, which is fine, as slow speed would be most appropriate anyway.
Thanks again! Happy Railroading.
Joel aka Owen W in CA