Are you Getting enough ?
A live steam engine will only give off its best if it is in good order but one thing that I think is overlooked is the power connections from the Hornby Controller to the track and the extra power leads to take the power to the far sections of the track to maintain the voltage and current.
Always use cables that have a high copper strand conductor diameter and use terminal blocks very sparingly plus keep cables as short as possible and solder wires to the track rails. These are my suggestions.
With the above taken care of my next idea was to build a test unit that can be fitted onto the engine and run the engine round your track carrying this small DVM as it goes thereby giving out a reading of the voltages constantly as it goes.
This small unit will not only tell you how good your track power pick up is but will also tell you how good the power from the tender wheels to the heaters are.
So the specifications are.
1. To read all track voltages at all times.
2. To give the high voltage readings within the engine
3. To give the low voltage readings for the servo motor.
Next hope fully will follow the unit and its operation in words and pictures.
Thanks - saves searching.