Evaluation of Deltang radio control system

I've been experimenting for some time with various options for the radio control of my battery powered locos (see How I constructed an 0-6-2T, How I constructed an IP Engineering diesel loco and How I constructed a two car rail motor). I've been trying to find the most cost effective way of controlling them which balances cost against operability.

My first venture into cheap radio control was through the use of a remote dimmer for LED lighting which uses a small keyfob (see Using an LED dimmer for radio control of a loco). Whilst this approach is very inexpensive (overall cost around £5), it does have limitations. At present, I have not found a way of reversing the loco remotely (though this could be done with another keyfob controller) and the control is not particularly smooth.

My second approach was to make use of a very inexpensive 2.4 gHz transmitter, a receiver and a controller designed for use with garden railways (see Evaluating a low cost transmitter for garden railway use). This provided a good level of control but although the transmitter was less than £5, the receivers cost around £10 and the controllers range in price from £30 to £75. A transmitter, receiver and controller is needed for each loco. A disadvantage is that the transmitters are primarily designed for aeroplanes or helicopters and hence the joysticks need to be held in position to keep the loco moving (though the transmitter can be turned off once the cruise speed has been set).

The Deltang transmitter

What attracted me to the Deltang system was firstly that up to twelve locos can be controlled from a single transmitter which has been designed specifically for use with railway locomotives. The transmitter has a control knob an inertia control knob and a loco selector switch. The second attraction was the cost. Once one transmitter has been bought (for around £60 - or as a kit for £25), there is no need to buy another. Furthermore, the combined receiver/controllers cost just under £30.

The receiver/controller

The receiver/controllers are very small in size, being intended for use in 00 or even N gauge locos as well as 16mm and G scale locos. Despite their size, they will handle up to 1.5 amps, which is fine for most of the smaller locos used on garden railways. The designer is planning a version which can handle more amps.

There are four wires attached to the receiver - black and red are for the battery supply (from 3 volts to 16 volts) and the two brown wires connect to the motor.

I use a connector block to make the removal of motor controllers easier, but if you are pushed for space, the receiver/controller could be hard-wired in.

There are several other outputs which can be used - but as yet I have not explored them. These include:

• Servo control - eg for remote uncoupling
• Forward lights
• Reverse lights

Binding

Binding is extremely easy. Firstly the receiver is switched on. There is a tiny LED which indicates the state of the receiver. Initially, it flashes every two seconds as it hunts for a signal from the transmitter. If it doesn't detect a signal after 20 seconds it goes into bind mode which is indicated by a rapid flashing of the LED.

To bind the transmitter, firstly the loco selector switch is clicked to the desired position (eg loco no. 2), the bind button is held down and then the transmitter is switched on - then the bind button can be released. The light on the transmitter flashes to show it is in bind mode and if all is well the LED on the receiver flashes in unison with it. 

After a few seconds the lights on both the transmitter and receiver stop flashing and show a steady light indicating the binding has been successful. The instructions suggest that it may take more than one attempt to bind successfully, but my experience so far has been that binding was OK first time.

Operation

Once each loco has been bound to a particular channel on the selector switch it will only respond when the switch is in that position. Speed and direction are controlled with the large knob at the lower end of the transmitter. I have found that very fine control is possible, though this is dependent on the responsiveness of the loco mechanism. Once a cruise speed has been set for a particular loco, the selector switch can be turned to control a different loco. The first loco will continue on its speed setting until the selector switch is turned back to select that loco again.

The default is for the receiver/controllers to bring the  loco to a controlled stop if the transmitter signal is lost (eg if the transmitter goes out of range or is switched off). However, this default setting can be reprogrammed to enable 'cruise control', whereby the motor will continue running on its setting if the signal is lost.

The inertia control is quite handy. I tend to set it to just under the half way mark. This provides a smooth start and stop and so is much more gentle on the loco's mechanism. The smoothness of the start and stop is dependent on the particular mechanism of the loco. One of my locos (with an LGB motor block) responds very well while another (with an adapted IP Engineering motor and gearbox) is less smooth. However, this mechanism is quite stiff and so may improve once it is run-in.

Programming the receiver

Several settings on the receiver/controller can be reset from the defaults by the user with a standard DSM2 transmitter or with Deltang's own programmer module. I have not explored the settings fully as yet but the following are just some of the settings which can be adjusted:

• Whether the motor will respond to the single speed/direction knob or a combination of the speed knob and the reverse switch
• The start and maximum speed setting for each loco
• The PWM frequency. The default is 60Hz but it can be set to 250Hz. There are also options to set for 2kHz and 16kHz but only for low power, low voltage motors.
• The time before the receiver goes to sleep if no signal is received
• Failsafe or cruise (ie whether the loco stops or continues when the transmitter is switch off or the signal is lost)
• Servo settings (eg for remote uncoupling)
• Output settings (eg for flashing lights or the momentary or latched switching of accessories

Evaluation

 I have so far tested the system on three locos and a bare LGB motor block. The smoothest and most responsive control is with the LGB motor blocks. The railbus, which has now been equipped with an MFA Como planetary gearbox motor and bevel gears is also very responsive. An IP Engineering diesel loco which has had its gearbox replaced with a homebuilt gearbox is somewhat unreliable. Mostly it responds reasonably well but occasionally it has difficulties starting off in reverse. This may have something to do with the mechanism or may be a feature of that particular motor or may have something to do with the metal body of the loco (my others have plastic bodies). I need to do more extensive testing to determine where the problem lies.

All my locos are powered with 12 volt battery packs. I did find, when trying to power the bare LGB motor block with a 6 volt battery pack that it experienced problems at the lower speeds - sometimes the motor would hum and struggle to get started, even when the speed knob was turned up. This may have something to do with the motor originally being designed to run off 24 volts, though.

I have also tested the system with a small loco designed to run off 3-6 volts. At 3v the system was unreliable, However, at 4.5v there was a marked difference. The motor was very responsive and controllable. The limitation of using the low voltage was that the range seem to be considerably more restricted and the signal more prone to interference from foliage etc. This video gives a brief overview of the system in 4.5 volts (please forgive the crudity of the loco - it was hurriedly built for this test).

On 12 volts or more, the maximum range of the system is said to be around 40 metres in ideal conditions. I have tested the system (with 12 volts) in my garden and found it responds without difficulty from one end of my garden to the other - approx 25m distant. I have not experienced any difficulty with interference from foliage or buildings - at one point my railway runs behind two sheds which are full of metal objects (mower, garden tools, trailer tent, etc.) and so far there have been no drop-outs in the signal. The receivers do not seem to draw too much current. I have accidentally left them on for several hours without any subsequent appreciable loss of battery power.

Overall, I have been very impressed with the system so far. I need to do more extensive and intensive testing, but the units seem robust despite their size. I think the plan to introduce a receiver with a higher amperage rating is a good move. Although most of my locos draw around 1 amp, I would imagine there will be occasions when it would be useful to have a higher ceiling. Price-wise, there seems little to beat this tailor-made system for the radio control of trains at present

 Video Evaluation

Update - May 2016

Since writing this blog entry, I have started producing my own versions of Deltang transmitters. See  http://rctrains.co.uk for more information ( March 2017 - I have now handed the business over to Phil Partridge )

I have also produced a range of other guides on using Deltang r/c gear:

• Getting started with Deltang radio control in the garden
• Using pads on Deltang receivers 
• How to program Deltang receivers  
• How to adjust the servo outputs from a Deltang Rx102 receiver 
• How I re-programmed a Deltang Rx65b receiver to operate in auto-shuttle mode with a Prog4
• How I reprogrammed a Deltang Rx102 receiver to control a DigiSounds soundcard with a Prog4 
• How I constructed a Deltang Tx20 transmitter from a kit (also Tx22 construction)

In addition, I have described the installation of Deltang r/c gear into a number of locos:

• Converting an LGB Stainz loco to battery r/c with a trail car
• Converting an LGB Stainz to battery r/c without a trail car
• Converting a Piko DB BR80 loco to battery power and radio control 
• How I installed a Deltang Rx65b in my IP Engineering Jessie loco
• Converting a track-powered loco (No. 1 Peckforton) to radio control
• Converting a track powered locos (No. 7 Tollemache) to radio control 
• Converting a small battery powered diesel loco to radio control (and auto shuttle)

 And how I interface sound cards with Deltang r/c gear:

• Triggering MyLocoSound effects from a Deltang Rx65 receiver
• Triggering MyLocoSound effects from a Deltang Rx65b receiver (v611-11)
• How to interface soundcards with Deltang receivers