Ok I went back and retested both trailers again using the same 1/2" vinyl hose. Before starting I made sure the dip in the manometer hose was at 7" below the 0" WC mark. This time instead of using the bleed off valve on the test device I had several appliances running.
On both trailers I had the refrigerator, water heater, 3 burners and the oven operating. It was 90 degrees outside so there was no way to make the furnace operate.
The Marshall regulator on the 2008 Safari had 12" static and 11" dynamic at the final adjustment.
The Fischer regulator on the 1994 Classic had 13" static and 11" dynamic at the final adjustment. Before testing the Fischer I flushed the main trunk of the propane line with acetone and compressed air.
I feel much more confident in the results of the test and I believe both regulators seem to be working properly.
Thanks all for responding to this thread.
Steve, Christy, Anna and Scout (Border Collie)
1994 30'11" Excella - rear twin
2009 Dodge 2500, 6 Speed Auto, CTD, Quad Cab, Short Bed
Hensley with adjustable stinger
WBCCI # 3072
AIR # 6035