Hey,
Thanks to all for replies...I have latest (2015) T.O's and also commercial manuals for the GTCP85-185L. Through these manuals there is a lot of conflicting information. Running the unit at 4292 -4311puts frequency at 410-412 hz. In the commercial world, I would expect a phone call right away as a commercial operator wants to see no more than 404 hz. Does the C-130 unit really operate at such a high frequency?
What I would really like to know is what do the guys in the cockpit want to see by way of generator frequency with no load? I understand the window of 380-420hz, but there must be something that seems "normal" or desired. On a related side note, our 85-180's for the A/M32A-60A hold 400hz even within +/- 1hz under any condition as they incorporate a clever stepper motor on the fuel control. The 85-180C for the -95 (LASS) cart states 43,300 RPM max by the T.O , but at installation is tweeked down to just around 42,200 -42,500 or else the tachometer reading in the panel looks a bit overspeed.
Thanks again for all the input...I am always working hard to maximize these units.