Which Dead Rail System Is For You?

After deciding that you actually want to move to a dead rail system, it’s time to decide which dead rail system you want to use. There are several competing systems on the market, and each system has certain advantages and disadvantages.

Combining Dead Rail with DCC

AirWire CONVRTR receiver
AirWire CONVRTR receiver

If you want to have sound and DCC-like capabilities, there are several similar systems available: CVP’s AirWire, Stanton’s S-Cab, and Tam Valley’s DRS1. All of these systems work by installing a receiver board in the locomotive that acts as both a radio receiver and a miniature DCC command station/booster. Both AirWire and S-Cab require using special transmitter throttles that provide programming and control options.

Stanton Radio Cab Transmitter
Stanton Radio Cab Transmitter

The hybrid, DCC-based systems can be expensive. Transmitters for these systems are around $150 each. The AirWire CONVRTR receiver board is $99. S-Cab receivers are not available without an attached DCC decoder, so the cost depends on the decoder — most are custom order and an adapted Tsunami TSU-1000 is $150.

CVP AirWire T5000 transmitter
CVP AirWire T5000 transmitter

An AirWire transmitter can run up to 8 locomotives at a time, and can use full 4-digit DCC addressing, on up to 17 UHF RF frequencies. This opens up a unique ability to have more than one locomotive with the same DCC address on the railroad at the same time.

Each S-Cab transmitter can run up to 15 locomotives simultaneously, but supports only 2-digit DCC addresses.

Tam Valley’s DRS1 system is unique in that it requires an existing DCC system for the cabs — it works with any DCC system from Digitrax, Lenz or NCE (and others) by connecting a small transmitter to the DCC Command Station. This allows a relatively seamless transition if you’re moving from DCC to dead rail. But, that also means that DRS1 requires a complete DCC system in order to operate. Also, you must know the radio frequency of your DCC system’s wireless cabs, so that you can order the correct versions of the DRS1 transmitters and receivers. Not all DCC manufacturers are eager to divulge that information.

Tam Valley’s system is a little less expensive, with transmitters and receivers running under $60 each. Only one or two transmitters are required for an average layout.

Finally, NCE has entered the Dead Rail business with a NO-SOUND decoder that is compatible with Tam Valley, CVP, and Stanton transmitters under certain conditions.

Pure Radio Control Systems

If you’re like me and want your control system to be dead simple, and you don’t require sound or a lot of other functions, then Deltang‘s equipment is probably for you. It’s the system I’ll be describing in detail throughout the rest of this primer.

Warning: The Deltang web site is cryptic at best. There’s a lot of information there, but it’s a little disorganized and hard to follow.

Deltang Rx61 Receiver
Deltang Rx61 Receiver

The Deltang system receivers were originally designed for use in radio controlled “micro flyers”, and so they’re very small, and can fit well into many different locomotives. Even so, the Deltang receivers can operate most HO or On30 locomotives with ease, and can operate headlights or other functions as well.

Like a DCC decoder, it is possible to completely customize the operation of the receiver. For instance, one of my friends prefers to operate in what would be referred to as “yard mode” by DCC operators — which means that the center position on the throttle is off, rotating the knob to the right moves the train forward, and rotating the knob to the left moves the train in reverse. I prefer the more “standard” mode of operation, where stopped is all the way to the left, and direction is controlled with a switch.

The receivers each have several control outputs that can be programmed as well. For instance, I’ve programmed one of the outputs to operate the headlight in such a way that the headlight comes on automatically after the locomotive is turned on and communication has been established with the transmitter. After that, the red function button turns the light off or on.

E-Flite 4-channel DSM-2 transmitter
E-Flite 4-channel DSM-2 transmitter

The Deltang receivers use a modern-technology 2.4GHz spread spectrum radio system, and can be used with standard Spektrum DSM2 R/C transmitters. Or, you can opt for one of the very easy-to-use Deltang transmitters that resemble regular model railroad walk-around throttles.

Finally, Deltang receivers are capable of monitoring battery voltage, and shutting off the motor control when the voltage drops below a specified voltage (by default, that’s 3V per battery cell). That’s an important feature when using LiPo batteries.

tx21-10-360x269
Deltang Tx21 transmitter

The Tx21 transmitter shown at right controls speed, direction, momentum and a single “function.”

Deltang also has a throttle that can operate one of twelve locomotives, and a simpler model that forgoes the momentum control in favor of two additional function controls. The single-loco Tx21 and Tx20 transmitters can be purchased assembled for $70, and the twelve-locomotive throttle is available for $88 assembled. While the transmitters are available from Deltang as kits, I’ve had a look inside the transmitter and decided that it is well worth the extra money to buy the transmitters assembled. It’s not that I couldn’t do it, but I’d just rather not spend the 45 minutes it would take on that particular task.

Deltang Tx2 transmitter module
Deltang Tx2 transmitter module

It is also possible to purchase the transmitter module alone, and “roll your own” train controller, which would allow access to more function controls. The transmitter supports up to seven “channels,” each of which corresponds to a function. Some channels are reserved. For instance, channel 1 is always the speed control, and channel 5 is always combined with the “bind” function which is used to pair a transmitter with a receiver. Other channels vary by configuration. For instance, if the receiver is set such that the throttle is “full range,” channel 3 controls direction and channel four varies the momentum effect.

CVP AirWire have recently introduced a new receiver that also includes motor and light control on board called the MicroAirWire Micro-Motion decoder. The existing version is fairly small, and I’m told that an even more compact version is in the works. This new receiver works with their existing T5000PRO and T1300OPS transmitters (at least one T5000 transmitter is required for receiver programming).

Other Considerations

Another consideration is the radio frequency and radio system used. I’ve touched on this briefly above, and mentioned a couple of caveats specific to the system. I’d like to offer another item to consider, and that’s the FCC. As of this moment, all of the frequencies used are considered to be “safe” from use by other services. However, the cell phone industry is lobbying the FCC to allow continued expansion of cellular services in the UHF band between 600MHz and 1GHz. That means that they want more of the 900MHz frequency band than they already control, and if relatively recent trends continue, they’ll probably get it. That means that it’s possible that consumer goods (aside from cellular communications equipment) operating in the 900MHz spectrum could become outlawed. They’ve already done this with wireless microphones operating in the 600Mhz-900Mhz bands. Since some of the spectrum the telecoms want is to be reserved for use by first responders, there will be little tolerance of any interference from the likes of toy trains, and fines are very stiff for enforced infractions. That’s why I’ve been recommending that people buy systems that operate in the 2.4GHz range.

With the exception of Deltang, none of the systems offer battery management as a part of the receiver, relying instead on a battery protection module (BPM) being built into the battery or as a separate circuit board installed between the batteries and receivers. Our experience is that some BPMs can interfere with charging and balancing of battery cells with several popular LiPo chargers.

Definitely Not Plug-and-Play

Unlike DCC, Dead Rail is not a mature technology. There is currently no “drop-in” solution to make this work — much like the early days of DCC. But, as more people get involved, new products will be become available to ease the installation process. For now, however, a good pencil soldering iron is going to be your “friend.”