The RCT-Tx22
transmitter

A quick introduction to the RCT-Tx22
Key features of the RCT-Tx22 transmitter

The RCT-Tx22 could be the only transmitter you will need to control all your battery powered locomotives. Rather than having a different transmitter for each loco, you can control each one separately from the this one controller. All you need to do is remember the Loco Selecta switch position to which you have bound your loco (I have twelve locos - numbered 1-12 - it makes life easier - I also have a list of the locos stuck on the back of the transmitter, just in case!). And you can bind as many locos to each Loco Selecta switch position as you wish.

If you are new to battery power, radio control or to RCT and/or Deltang, then you might want to take a look at the FAQs (Frequently Asked Questions) in the Support section. Below is a quick tour of the key features of the RCT-Tx22 to help you decide if it is the transmitter for you.

The RCT-Tx22 is housed in a convenient hand-held case. Because it uses 2.4gHz radio control technology, the short aerial (antenna) is housed inside the case, giving the transmitter a range of up to 30m outdoors (20m indoors). However, the range is affected by buildings, damp foliage, people and the metal bodies of locomotives. It is important therefore that the receiver antennae have as clear a line of sight as possible to the transmitter and are positioned vertically in the loco to ensure they cannot be facing the transmitter end-on. With metal bodied locos, the receiver antennae should be positioned outside the body of the loco to avoid masking the signal (some examples of receiver installations in live steam locos). The RCT-Tx22 is suitable for use in small or medium sized garden or indoors.

The transmitter is powered by a 9v PP3 battery which is inserted in a battery compartment accessible in the base of the transmitter. I find that one alkaline battery usually lasts about a year - but that of course will depend on how frequently you run your railway.

One of the great virtues of the RCT-Tx22 over more conventional transmitters is the use of rotary knobs and switches to control your locos, rather than joysticks. The functions of the transmitter controls is described in outline here - with more detail further down the page.

Speed knob
The speed knob controls Channels 1 and 6. It is a 300° rotary control with 'centre click'. The knob can control speed and direction or just speed when used in conjunction with the direction switch. This depends on how the receiver has been programmed (see Receivers

Selecta knob 
The Selecta knob uses Channel 2 and sets the RCT-Tx22 apart from most other transmitters. The rotary switch allows 12 locos to be independently controlled from one transmitter. The receiver in each loco (or several locos) is bound to one of the switch positions - when the switch is turned to a particular position, it controls whichever loco or locos are bound to that position. When the switch is turned to a different position, the loco(s) bound to any of the other switch positions continue doing whatever they were previously doing. This feature works only with receivers programmed for interpreting Selecta signals  (eg RCT-Rx65b and RCT-Rx102). The RCT-Tx22 is fully compatible with Deltang transmitters and receivers.

Direction switch
The direction switch controls Channel 3. With receivers programmed for 'centre off' control (ie when the speed knob is used to control both speed and direction), this two-way switch can be used to switch on lights or trigger sound effects on a soundcard. When used with 'low off' receivers, it is used to control the direction of the locomotive while the speed knob only controls the loco's speed - stopped when turned fully to the left, full power when turned fully to the right . See the Receivers section for more information.
NOTE: The transmitter can be constructed with a latching or a self-centring direction switch. If you intend to use the transmitter primarily to control locos fitted with 'low-off' receivers then you would probably want a latching switch to remind you which direction the loco is programmed to travel. However, if you intend to use the transmitter primarily with 'centre-off' receivers, then you will probably want to use the direction switch to operate accessories such as triggering soundcard effects. A self-centring direction switch would be more suitable for this primary function.
 
Inertia knob 
The inertia knob slows down changes caused by the speed knob - ie if the inertia knob is set to (say) half way, when the speed knob is turned to a setting, the loco will slowly build up speed and slowly come to a halt when the speed knob is returned to zero. When the inertia knob is on its zero setting (ie fully to the left), changes to the speed knob occur immediately.
 
On/off button
The illuminated push-button turns the transmitter on and off. The LED also provides information for the user - it flickers when inertia control is active (ie when the loco is speeding up or slowing down under inertia control) and it flashes once a second during the binding process (see Bind button below)

Bind button
Receivers need to be 'paired' with the RCT-Tx22. The binding process is only necessary once per receiver. To bind a receiver to the RCT-Tx22
    1. Turn off the RCT-Tx22
    2. Put the receiver into bind mode (eg with the RCT-Rx65b, switch it on and wait 20 seconds until its LED flashes rapidly). 
    3. Turn the RCT-Tx22 Selecta switch to the position wanted for this loco. 
    4. Press and hold the bind button on the RCT-Tx22
    5. Switch on the RCT-Tx22 and then release the bind button. 
    6. Binding is complete when the LEDs on the transmitter and the receiver stop flashing. 
 Once the Tx is switched on, the bind button can be used to control receiver outputs via Channel 5 (eg to sound the whistle on a soundcard).


For the more technically-minded
The transmitter is capable of using seven channels. Channels 1 and 6  are used for speed control, Channel 2 is used by the Selecta system, Channel 3 is used by the direction switch, Channel 5 is used by the bind button and so can be used to control accessories when not being used for binding (eg I use it mostly to sound the horn or whistle on locos with soundcards), Channels 4 and 7 are not presently used on the RCT-Tx22 as purchased but it is possible to change the function of the inertia control knob to operate Channel 4 (or Channel 5).

  • Changing the inertia knob to control Channel 4 allows the transmitter to control an additional channel (eg for triggering effects on a soundcard)
  • Changing it to control Channel 4 also allows the RCT-Tx22 to reprogram the RCT-Rx65b and the RCT-Rx102 receiver (see below). 
  • Changing the inertia knob to Channel 5 gives greater control of this channel than with the bind button. 

To change the Inertia knob function to operate Channel 4: 
  1. Switch on the RCT-Tx22 and wait for 90 seconds without touching the bind button. 
  2. Now press and hold the bind button. 
  3. After 20 seconds or so, the LED will go out for two seconds and then come on for three seconds. 
  4. Release the bind button during this three second period
  5. The inertia knob is now set to control Channel 4. 
To change the Inertia knob function to operate Channel 5:
  1. Switch on the RCT-Tx22 and wait for 90 seconds without touching the bind button.
  2. Now press and hold the bind button.
  3. After 20 seconds or so, the LED will go out for two seconds and then come on for three seconds.
  4. After approximately 25 seconds, the LED will go off and stay off until you release the bind button. 
  5. This sets the inertia knob to control Channel 5. 
To change the Inertia knob function back to operating the inertia control:
  1. Switch the RCT-Tx22 on and wait for 90 seconds without touching the bind button.
  2. Now press and hold the bind button.
  3. After 20 seconds or so, the LED will go out for two seconds and then come on for three seconds
  4. Release the bind button during the three second period
  5. The inertia control knob will now be reset to its default setting (ie controlling inertia)
NOTE: 
  • If the inertia knob is being used for Inertia, the bind button controls Channel 5 when pressed for less than 20s. 
  • If the Inertia knob is being used for Channel 4, the bind button controls Channel 5 when pressed for less than 20s. 
  • If the Inertia pot is being used for Channel 5, the Bind button has no effect on Channel 5 but is still used for binding and reprogramming the inertia knob. 
Bind Button functions summarised
The Bind button can be used as follows: 
  • If the Bind button is being held down while the Tx is switched on, the Tx will enter Bind mode (see above). 
  • If the Bind button is pressed for less than 20 seconds at any time, it will normally control Channel 5. 
  • If the Bind button is pressed for 20 seconds or more within the first 60 seconds of switching the Tx on, it will perform calibration
  • If the Bind button is pressed for 20 seconds or more after the first 60 seconds of switching the Tx on, it will toggle what the Inertia control is used for (see above)

Reprogramming the RCT-Rx65b with the RCT-Tx22
If the inertia knob has been changed to control Channel 4 as above, then the RCT-Tx22 can change settings in the RCT-Rx65b. However, there is a risk that you may accidentally reprogram a receiver to act in unexpected ways and so only reprogram a receiver if you are confident with what you are doing (for more information on programming see the Support section). If a receiver is put into programming mode by mistake, switch the receiver off and centre the Selecta and Inertia knobs before switching the receiver on. 
 
To put the RCT-Tx22 into programming mode: 
  1. Set the Inertia knob to control Channel 4 (as above). 
  2. Rotate the Selecta (Ch2) and the Inertia (Ch4) knobs either fully left or right (ie not centred). 
  3. Make sure the Direction switch (Ch3) is in its central position. 
  4. Put the Throttle into the 'off' position. 
  5. Switch on the RCT-Tx22
To make changes to receiver settings: 
  1. Switch on a receiver which has previously been bound to the RCT-Tx22.
  2. The receiver LED should start flashing rapidly within a few seconds to show it is in programming mode
  3. Center the Selecta knob (ie position 6) and the Inertia knob. 
  4. Push the Direction switch (Ch3) to the left and centre again to Adance the settings within a particular level. 
  5. Push the Direction switch (Ch3) to the right and centre again to Accept a setting for that level. 
For more information on programming receivers see the Support section and/or my blog posting on programming receivers
 
To disable the programming mode: 
  • Change the Inertia knob back to controlling Channel 5 or Inertia (as described above)