Sorry if I have stirred up confusion Max
I was sort of replying to a couple of other posts in the thread.
The Soundtraxx sierra board really needs DC (straight track or battery power) BUT it will put up with PWC as long as things like the chuff rate are actually triggered mechanically.
If you look under your tender you will see some small magnets on one of the wheels and a sensor glued to the bogie frame. That is the sensor trigger that tells the Sierra Board how fast the loco is travelling and how many chuffs to sound.
If you turn the sound on and then push the tender on its own and, as long as the big back-up 6V battery is charged, it will chuff as the magnets trigger the sensor.
This 'mechanical chuff system' will work with PWC (PWM) as the Sierra board is not having to sense the voltage to make the chuff speed.
The only problem comes with the sounds that are put on auto mode on the Sierra board (grade horn blasts etc... see the instruction manual) which are not mechanically triggered by magnets in the track etc. PWC can sometimes confuse the Sierra board and make these auto-generated sounds go off all over the place.
HOW IT IS IN YOUR TENDER AT THE MOMENT:
A double cable links between the loco and tender
In your tender is the wiring that:
A) picks up from one side of the bogie axles and goes to the terminal block in the tender then single (of two) cable out to the loco..... also from the tender terminal block, one cable goes to the regulator (like the one in the smokebox) and then to rear light
B) takes the single feed back from the loco to the tender terminal block and goes through to the voltage regulator (like the one in the smokebox) and then one cable from regulator to the light to the rear light
C) the power feeds for the Soundtraxx sound card which will use both of the feeds above. (one goes to terminal 8 on the board and one goes to the on/off power switch under the water filler cover). There is also the Sierra back-up battery specific cabling.
D) The wheel magnet chuff trigger feeds to the Sierra board (terminal 11 &12 in the diagram)
The wiring diagram below is how the basic DC track power set up and how it is in your tender at the moment.
The left and right rail pickup feeds (A and B above) not only power the board and feed the voltage for the 'auto' chuff gauging system (you are not on auto chuff as you have a magnet trigger) but it also charges the back-up battery.
You will not need the separate back-up battery as you will be using a big power battery and this can do both jobs.
Do not get rid of the mechanical magnet chuff triggering it is practically bang on for 4 chuffs per revolution and not only does it work with PWC, it is always more accurate than using the auto-chuff system.
View attachment 245273
To get rid of any PWM problems you will be using one of John S' converters.
When you change over to the RC setup you will be using terminal 8 & 7 to connect from the PWM converter.
The other end of the PWM converter will connect to the loco feeds from the RC ESC (also called the motor feeds)
Here is a diagram for John S as it shows what is needed for a converter for a battery powered PWM ESC ....
Although you will not need a backup battery, the Sierra board does need to see about 6 to 8 volts at its back-up battery connector...that is why you need the 8v output shown in the diagram below.... the copy of the Aristocraft, converter that John S will create, supplies this Motor output and the 8v for the back-up battery connector
View attachment 245275
If you are having any problems or need a hand in the installation bring her over and we can set it up over here. It would be good to see her again!!