DCC without wires
One might be forgiven for thinking that the name 'Timpdon' refers to a children's TV programme, set in a cosy village of the same name, where all the people are unbearably good-natured and all the animals are unrealistically well-behaved. For all I know this may be the case, but it is also the name of a supplier of radio-control units. They are based in Altrincham and specialise in controls for garden railways.
So far, so ordinary. What makes them different is mainly twofold. Firstly the equipment was developed as a means to control locomotives on a particular railway, namely the portable and highly-popular 16mm layout 'Timpdon Lake', a veteran of exhibitions in the North-West (and further afield) for more than ten years. The system was therefore purpose-designed for the job. Secondly the transmitters operate at 433MHz, which is a good few kilocycles below the current crop of 2.4GHz units almost universally used to control trains, boats and planes, and cars. As to why this is much better I hesitate to say, mainly because I don't really know. I can however point you in the direction of a Technical Note, should you really wish to discover for yourself.
However, there are some advantages apparent even to the technically impoverished. The transmitter is really small and light, about the size of a mid-range smartphone, but somewhat thicker. It can easily be held and operated by one hand, leaving the other free to twiddle gas regulators, re-rail misbehaving stock or hold a modestly-sized plate of comestibles. Speed is controlled by a rotary knob and direction by a simple switch. Experience so far is that locos seem more controllable and responsive to the thumb of command than is normally achieved with conventional radio control. There are auxiliary switches for lights, horns or whistles, and one model in the range can operate up to ten different locos by rotating a selector. Which means you only have one transmitter to spill tea over, drop in the pond or leave out in the rain. Or in my case, leave at home.
The multi-channel transmitter also creates a significant operational advantage, in that it is much easier for one person to control two or more locos at (more or less) the same time. A train can be parked in a passing loop and control changed to another which then drives past it. The sort of thing that smaller-scale train drivers have been doing since Frank Hornby was a lad, but is fairly rare in garden scales. It is also possible to specify that a train will continue running once control has been changed to another, the default being that it comes to a halt after ten seconds. Most operators using conventional equipment only drive one train at a time, no doubt because holding two bulky transmitters simultaneously not only strains the wrists but also leaves no spare hand for the G&T.
Each loco carries a small radio receiver, which is wired to a controller unit. For live-steam locos this operates the servos for the regulator and reverser. As not all servos are the same, calibration facilities are provided for no less than ten different parameters. For battery-powered locos, the controller directly governs the speed and direction. Third-party electronic speed controllers are also catered for, using a special interface unit. Other modules are available to control points and signals.
If there is one downside, it's not a particularly cheap system, although having the multi-loco transmitter option is quite a money-saver. It seems a straight choice between something mass-produced in China for model aircraft and a well-engineered UK-made specialist model railway product. For many there is no argument, preferring to spend their limited resources on rolling stock and track rather than on smartypants controllers. However this particular modeller is gradually (and some would say at his age, about time) realising that quality is sometimes worth paying a bit more for.
First published in the newsletter of Southport Model Railway Society.