Digital Command Control can seem intimidating, making some novices reluctant to make the switch from direct-current power packs. An upgraded version of the Zepyhr set introduced several years ago, the Digitrax Zephyr Xtra 3.0-amp starter set packs everything needed to add DCC to a medium-size layout into a single box. Though it’s presented as a basic, all-in-one set, the Zephyr Xtra includes powerful functions and expansion capabilities.
All-in-one. A typical DCC setup consists of three components: the base station (the brains of the system), the booster (the power for the trains), and the throttle (the engineer interface). The Zephyr Xtra set puts all three components into one box, which Digitrax calls the DCS 51 Command Station. The only connections needed are the power cord (which has an integrated AC/DC adapter) and two wires to the layout’s power bus. This makes setup on a model railroad quick and convenient.
The command station has a four-digit light-emitting diode numeric display, a 24-button keypad, a forward/reverse/brake lever, and a throttle knob reminiscent of a DC power pack. This kind of throttle makes the Zephyr controls more accessible to those converting from DC, but it has the drawback of imprecision. There’s nothing to indicate what DCC speed step a particular throttle knob setting corresponds to.
Connecting the DCS 51 to a track bus is accomplished by a set of screw terminals on the back of the control box. The terminal strip itself plugs into the back of the box, making it convenient to get to these connections even if you mount the box in a drawer or under the fascia. Just unplug the strip, make your connections, and plug it back in.
The terminal strip includes one set of contacts for the layout’s power bus, plus two more for a programming track. The DCS 51 supports decoder programming on the main (also called “ops mode” programming), but wiring an electrically isolated track as a programming track is necessary to read back decoder configuration variables (CVs).
Also on the terminal strip are three contacts labeled Jump 1, Jump 2,
and Ground. These allow the user to connect two standard direct-current
power packs to the DCS 51 for use as additional DCC throttles. Though
these analog throttles wouldn’t be able to control decoder functions
such as lighting and sound effects, this is a thoughtful feature for
users just converting from DC who don’t want to lay out the cash for
extra throttles just yet.
The back of the command station also features two LocoNet ports. These allow you to connect compatible corded throttles, wireless throttle receivers, or even additional DCS 51s. The system supports up to 20 throttles (including its own). The command stations can be daisy-chained through LocoNet to serve as power boosters, additional throttles, and even as auto-reversing units for wye tracks or return loops.
LocoNet uses standard computer Cat5 Ethernet cables. The Zephyr Xtra starter set includes an LT1 decoder and LocoNet cable tester, which lets the user check a cable for compatibility or diagnose a bad connection.
Testing 1-2-3. I connected the Zephyr Xtra system to a test track in our workshop and tried it out with a number of decoder-equipped locomotives. Though I found the large number of buttons daunting at first, most of them are used only in special situations (like decoder programming), and I had my first locomotive running in no time.
The DCS 51 is rated at 3 amps (A). Depending on the current draw of your locomotives, that should be sufficient to run several engines simultaneously. Though older locomotives, O scale engines, and those equipped with sound decoders can draw close to 1A when stalled, HO and N scale locomotives typically draw less than half that under normal operation. The DCS 51’s 3A should be enough current to run three or four sound-equipped locomotives at once.
The control station’s numeric keypad is conveniently labeled with icons to remind you which function keys typically correspond to the bell, horn, and headlight on decoder-equipped locomotives. Two “shift” buttons let the user control as many as 29 functions on more advanced decoders. Light-emitting diodes indicate when these buttons, or functions such as programming mode, mute, and brake, are active.
By connecting my test track to the programming track terminals, I was able to easily read and program CVs on a decoder-equipped Bachmann locomotive, changing its decoder address and altering its starting voltage (CV2) and acceleration curve (CV3) for better low-speed performance. However, I was unable to read CVs on two locomotives equipped with SoundTraxx Tsunami decoders. This is a common issue with high-current-draw sound decoders, and would probably be rectified by use of a booster like Digitrax’s 5-amp DB150.
If you’ve been considering switching your layout from direct-current to DCC, the Digitrax Zephyr Xtra set is a great way to start. Despite its simple appearance, this system’s expandability make it the core of a system that can grow along with your layout and your expertise.