TCS UWT-50 Preference: Encoder or Potentiometer?

BigJake Jan 11, 2023

  1. BigJake

    BigJake TrainBoard Member

    I'm considering purchasing a CS-105 Command Station & UWT-50 throttle bundle...

    There is an option for encoder or potentiometer knob on the UWT-50 throttle.

    As I understand it the encoder knob rolls over and over, whereas the potentiometer knob has a hard stop at 0 speed.

    When you switch locos/addresses, the encoder version assumes the existing speed setting from the new loco, and lets you adjust up or down from there by rotating the knob in either direction. I'm not sure what the potentiometer version does when you switch locos/addresses.

    I kinda like that feature for the encoder version, but I also like having zero always being at the same knob angle on the pot version.

    Any preferences/reasons for favoring one version over the other?
  2. CSX Robert

    CSX Robert TrainBoard Member

    I prefer an encoder for two reasons. One is what you mentioned, being able to select a loco at its current speed. The other is for precise speed control when switching - I like to know exactly what speed step the loco is on and to be able to adjust it one step at a time.
    Sumner and BigJake like this.
  3. James Fitch

    James Fitch TrainBoard Member

    I purchased the TCS UWT-50P potentiometer. So there you have 1 for encoder and 1 for pot.
  4. BigJake

    BigJake TrainBoard Member

    "Six took stick; six took spray!" (1970's TV commercial for Right Guard deodorant)

    James, I assume you prefer the fixed knob rotation stop for speed zero, or is it something else?

    What happens if you switch locomotives on the potentiometer throttle; does it immediately set the new loco to the speed indicated by the existing knob position (i.e. typically the last speed command for the previous loco)?

    Is there a setting for the potentiometer throttle version where half-scale is zero speed; less than that is reverse speed, and greater than that is forward speed?
  5. Sumner

    Sumner TrainBoard Member

    Not the same throttle but ....


    ... I like the encoder using EngineDriver on the phone. Thought I'd like a pot better but really like the encoder after using it. It is easy to move one speed step at a time. I feel that is probably that it doesn't have a limited range like a pot so you maybe have to rotate the encoder a little further for each speed step giving it better resolution.

    Also since you have multiple choices for the throttle layout with ED (more than one or like you mentioned the option of go up to increase speed in forward, come back to zero speed and keep going and increase speed in reverse or as I prefer the need to change direction).

    Jake I believe you use EngineDriver. If so and you haven't done it for about $35 you could have the encoder to try out using it before you make a decision. I'm sure it is going to come down to individual personal preference. James or Robert have you used both? Robert sounds like maybe you have?

    It would be interesting to see some reviews comparing EngineDriver to some of the popular commercial throttles and reviews between them showing the features they have or don't have. A nice chart with features and the little x's in boxes showing which features a throttle has or doesn't have. Maybe we could create one? Compile a list of possible features and those of us that have a throttle could respond to which ones their throttle has.

  6. BigJake

    BigJake TrainBoard Member


    Yes, I currently use my Android phone running EngineDriver with my Pi SPROG 3 DCC system, running JMRI on the Raspberry Pi host. I am very familiar and satisfied with the Engine driver app.

    However, I'm considering purchasing a TCS CS-105 Command station. By itself, the CS-105 cannot talk to WiThrottle WiFi throttles, unless you use a computer running JMRI, connected to the CS-105.

    The CS-105 supports LCC protocol throttles over WiFi (or the LCC CAN bus interface included). As such, TCS offers bundles with either of their throttles at reduced cost. Their throttles are user-configurable for LCC or WiThrottle protocol support.

    Alas, there is not yet an LCC throttle app for Android phones (there is one for iPhones).

    Since LCC is a NMRA standard, and WiThrottle is not, I would prefer moving forward with LCC, but use WiThrottle as a backup/extra as needed.

    If I move forward with a CS-105 & Throttle bundle, I would be happy to compare the two throttles online here.
  7. CSX Robert

    CSX Robert TrainBoard Member

    I have used both encoder based and potentiometer based on a Digitrax system. It definitely does come down to personal preference - as I said, I prefer the encoder, but I can definitely see why some prefer the pot.

    I haven't seen any mention of what the UWT-50 does. With my Digitrax UT4D the locomotive does take on the current setting of the pot if different, but not immediately. It gradually changes over a few seconds so that you don't get a sudden change in speed.

    Yes, it's called yard mode and there is also a detent at the halfway point so you can feel when it's at zero.

    A little more information on an encoder versus a potentiometer: As mentioned, I prefer the encoder's fine control when switching, but I actually don't even use the encoder when switching - I use the +, - and direction buttons (and potentiometer throttles don't have + and - buttons). In fact, I haven't considered the new DT602 because for some reason Digitrax did away with the + and - buttons. Using those three buttons I can hold the throttle in my left hand, push the buttons with my thumb, use an uncoupling stick in my right, and have complete and precise control over the loco without ever looking at the throttle.

    The yard mode on the UWT-50 would certainly help, and when in yard mode it also decreases the maximum throttle setting (which is adjustable) to give you more precise control. I would still prefer the three button control for switching, though, because with the pot you still wouldn't have speed step at a time control without looking at the throttle.

    Another reason I prefer the encoder, at least on Digitrax, is the potentiometer throttles do not have displays, so to know exactly what speed step your on you have to use an encoder throttle. This is critical when speed matching and also very useful when running more than one train on a track (which I often do) and trying to run them at the same speed. The UWT-50 does display the loco's throttle setting, so it's really not an issue here.

    There is one thing I do not like about encoders. If you use one speed step per click, in 128 speed step mode it would take multiple rotations of the knob to go from zero to full throttle or vice versa. To compensate for that, manufacturers use what's called ballistic tracking - the faster you turn the knob, the more speed steps you get per click. The ballistic tracking works well in my experience, but it does mean that the same amount of turn on the knob is not always the same number of speed steps. I do consider it a minor issue and just the price of having finer control.
    James Fitch, BigJake and Sumner like this.
  8. BigJake

    BigJake TrainBoard Member

    Thank you; this info is very helpful, and just what I was looking for!
    James Fitch likes this.

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