While DelTang offer several throttle choices, I’ve found that the Tx21 and Tx22 throttles are by far the two most popular options, which is why I’ve only been carrying those two. The only difference between them is that the Tx21 is a “single loco” throttle, and the Tx22 offers “Selecta” control of 1 of 12 locos. However, just because the Tx21 doesn’t have the Selecta feature, that doesn’t mean that it can only control one locomotive, because it is possible to bind an unlimited number of locos to a single throttle — the process of binding tells the receiver which throttle it can accept commands from. Any loco that has been bound to a Tx21 throttle will respond if it’s turned on. So, if you’re a lone wolf who only ever runs one loco at a time, you very well may not need the Selecta feature of the Tx22, saving at least a few dollars and a fair amount of time.
The Tx22 throttle is for folks who might want to run multiple trains simultaneously, and switch quickly between them. Generally speaking, a receiver with the Selecta feature will continue to run as long as its associated throttle is turned on, even if the Selecta knob is set to control a different loco. What does not work, for example, is trying to get a loco to run on position #1 on two Tx22 throttles — there’s still the limitation that a receiver can only be controlled by one throttle, unless you choose to rebind the loco to another throttle.
Note: It is possible to specially program receivers to allow control by more two throttles, however this is a very advanced function and is not to be considered a normal operating mode.
Since DelTang no longer offer pre-assembled throttles, it’s now up to you to build your own. The good news is that it’s really not that hard to assemble, calibrate, and test the throttles, but some care is required.
The pictures at right show the inside of the Tx21 and Tx22 throttles. As you can see, it’s a little cramped inside the case, but there aren’t a huge number of components. Anyone with reasonable soldering skills should be able to build either the Tx21 or Tx22 without difficulty.
The biggest difficulty in either case is that the instructions provided on the DelTang web site and with the kit are sketchy at best. You will need to understand how to read the schematic diagram provided, and be able to interpret the pin layout on the included transmitter module.
- Electric drill and bits
- Diagonal cutters
- Wire stripper
- Needle-nose pliers
- #1 Phillips head screwdriver
- Soldering iron (25-35W) with a fairly small tip (1/16″ conical or chisel tip is a good choice)
- Hot air gun or “grill-starter” lighter (for heat shrink tubing)
- 60/40 rosin-core solder
- 28AWG stranded hookup wire
- 3/32″ or 1/8″ heat shrink tubing
- E6000 or similar glue
- 9V alkaline battery
You will need to drill the holes in the case for the switches and potentiometers, using the drilling template, which you’ll also need to interpret — they are a little confusing.
Once you’ve assembled the throttle, it must be calibrated so that the throttle sends the correct values for speed, momentum, and “Selecta” (in the case of the Tx22). If you don’t calibrate the throttle correctly, the results can be an erratic or non-functional unit — until it’s properly calibrated.
If you don’t have a lot of experience building electronic kits, choose the Tx21 for your first throttle even if you plan on using Tx22 throttles in the future. Once you get the hang of building the Tx21, you’ll be better equipped to construct a Tx22. Several of the experienced DelTang users that I know tried the Tx22 throttles, but elected to use one Tx21 throttle for each loco in the long run.