Sheldon,
Thanks for writing. In answer to your questions.
Yes, my system can use up to 10 different channels. The entire thing is
done with a 433 MHz (or 315 MHz) analog broadcast frequency. The data messages are sent with simple “OOK” (on/off keying) style pulses. Each command begins with a preamble and ends with a CRC so that there can be no bad messages acted upon by the receiver. At worst, if there is interference, the message would be corrupted, interpreted as junk by the receiver and ignored. I put the channel number in the message itself. So all receivers in the area will receive all messages, but a receiver set on, say, channel 5, would simply ignore any messages it gets that don’t have channel 5 in the message header. Because all the logical channels share the same frequency, it is possible that with a lot of transmitters in close proximity, all sending at the same moment, they can interfere with each other. To get around that, I send all messages multiple times, randomly spaced, to make it almost impossible for at least one copy to not get through. I have tested this by setting my transmitters in a special mode, where they just go nuts, randomly sending messages constantly, at random intervals. I set up 4 of those in a small room doing this, while I ran a train with a 5th one, just to make sure that my messages would get through reliably, despite all the interference. And it works really really well. In a real world situation, you could never have 5 (or 9) other operators all pounding away with messages like that. In addition, remember that I said I could use 433 MHz or 315 MHz. So a really robuse system with a LOT of channels in use (like the maximum 10) could have 5 build to run on 315 and 5 on 433, so that any given one would only ever have to compete with up to 4 others on the same frequency.
Range: I tested it out to 50 feet, through two interior home walls. and it works without a single miss. ( I set up the the transmitter inside, then walked outside to my backyard, and went all the way to the back of my property). Without any obstructions (just line of sight), I’m sure it could go further.
The receiver goes under the layout, and connects to the throttle module, which is a fairly traditional transistor based linear current amplifier. It uses smooth DC with half-wave 60 Hz pulses superimposed on it. The pulses come on as soon as the throttles comes off “zero”, and the ramp up in amplitude as the throttle goes up. Then, at about 8v, they gradually diminish, so that by 11v, they are all gone and it is smooth DC. I specifically did NOT use PWM, because PWM can really mess up DCC decoders, and I built this for DC users, who may also want to run a DCC-equipped engine in DC mode from time to time. 60 Hz pulses are very good to keep a DC motor turning at very low speed, with no noise and no heat.
The speed control is a knob. I find it interesting that you say you liked the pushbuttons on the Aristocraft. When I designed mine, every single person I asked said they would always prefer a knob to pushbuttons (speed up/down), and it took quite a bit of work to make a system that used a knob. Personally, I prefer a knob.
Are you using the Aristocraft for N guage? The original poster wanted something for N. I thought the Aristocraft system was designed to have the receiver carried on-board in the loco, so it was intended for large scale trains like O or G. Although, I supposed you could mount the receivers under the layout, and just connect them to layout blocks. Is that how you are using it with your cab control system?
Thank you again. If you have more questions, or know anybody who might be interested in this system, feel free to contact me. I originally built this thing as a simple transistor throttle way back in the 1970s for my own layout. Then, I decided to completely update it with some circuit modifications for better performance, and as I kept redesigning it, I ended up adding the wireless capability to it and decided to make it public in case anybody else could use one, since DC throttles don’t really exist anymore except for MRC and a few cottage makers.
– Max