Hello Jon and Pete.
The module that Pete has is tiny. About the size of a thumbnail. No adjustments just a whistle. A recording of the L & B “LYN”.
Just plug it in to the 5v R/C system and add a 8 ohm speaker.
They are made by Mike Ridley in the UK and are part of a range of Tug Boat horns etc
Mike can load any 16 second (max) sound clip for the cost of the pcb and cable. The logic is triggered by a pwm (servo) signal on any spare channel.
I do acknowledge that technically echo should not be there. However, IMHO, it is the echo that gives the sound “character”.
Again, IMHO, I believe the echo is what steam whistle fans like because that is what they actually hear from a loco. The problem usually is that when a good whistle sound is available, it is often accompanied by other extraneous sounds such as chuff, rail clik etc which is usually not easily removed.
I understand that a suitable USA mainline whistle would be in demand. Mike will kindly do whatever I ask of him with regards to the products from his range that I sell.
His range consists of directional constant brightness lighting, ditch lights and an array of R/C switches for turning stuff on and off.
If Jon would give us permission to use the clips in the videos I am sure we could come to some sort of equitable agreement as their application.
There is also a way of using existing stand alone sound systems such as MyLocoSound, Phoenix and Dallee with Live Steam locos, no matter what voltage they would normally operate on. However, doing it that way, could be a bit more complicated depending on voltage requirements.