AirWire 900 is finally shipping

[cacole]

After almost a year of waiting, I finally received my AirWire 900 DCC system from CVP Products, on July 2nd. My initial impression is that CVP has incorporated all the features of their EasyDCC system into this product, so there is no learning curve at all if you already have the EasyDCC wireless system that you're using for other scales. The biggest difference between AirWire and EasyDCC is that you must use on-board battery power for G-scale instead of track power. This is really a big advantage, since you will never need to clean track again, and that feature alone made the wait more bearable.

I'm now in the process of installing the AirWire 900 into a Bachmann Spectrum Consolidation. I installed the receiver inside the boiler, since there was plenty of room for the small circuit board and antenna. The receiver has its own DCC-controlled motor driver, headlight circuitry, and smoke generator circuitry. A SoundTraxx Sierra sound decoder and 3-inch speaker are in the tender, along with the batteries.

I stripped all of the Bachmann circuit boards out of the locomotive, since they had been dead on arrival anyway. When I purchased the Consolidation new, it didn't work. I discovered that three wires had not even been soldered to the internal circuit board when it was assembled in China, and a couple of other solder joints were so poorly done that their wires soon pulled loose. Every wire was red or black, so there was no way of knowing what wire was supposed to be soldered where. Bachmann's answer to my question concerning a wiring schematic of the locomotive and the wiring color code was, "The factory just uses whatever color of wire they happen to have on hand, and they have provided no schematic of the circuit boards."

I eliminated the firebox flicker LEDs and circuit board, threw away the main circuit board, and added a resistor to the headlight LED wiring. The smoke generator is still wired through the on/off slide switch behind the smokebox front, even though it can also be turned on and off with the AirWire controller. I kept the Bachmann switch intact so an accidental activation of the smoke generator using the AirWire hand-held controller wouldn't unnecessarily drain the battery or burn out the smoke generator if it had no smoke fluid in it. The NMRA / NEM switch behind the smoke box front was taken out and discarded, since it serves no purpose with AirWire. All of the track pickup wipers and wiring were removed from the locomotive and tender. The smoke box flicker LEDs could have been salvaged, but using them would have required the addition of more interconnections between the tender and locomotive, since the SoundTraxx Sierra decoder would have to be used to control this feature, and I wanted to avoid the addition of wires between the tender and locomotive.

My initial attempt was to use two Radio Shack 9.6 Volt, 1000 mAh NiCad race car battery packs, wired in parallel to provide 9.6 Volts at 2000 mAh, installed in the rear of the tender behind the speaker enclosure. They have proven to be too weak to power the engine, and take far to long to recharge, so I have ordered two 12 Volt, 5 Ah GelCell batteries and one 12 Volt, 1.2 Ah GelCell. I'm initially going to try the 1.2 Ah GelCell mounted crossways in the back of the tender, and see if that provides enough run time. That's the battery that CVP recommends. If that single GelCell isn't strong enough, I'll add the two 5 Ah batteries in a trailing boxcar.

Wiring the 9.6 Volt race car batteries in series to produce 19.2 Volts at 1000 mAh was considered, but soon abandoned. The AirWire 900 circuit board is rated for an input voltage of 12-18 Volts, and the SoundTraxx Sierra is rated for a maximum of 16 Volts. The no-load voltage of the Radio Shack batteries measured as 10.2 Volts, so wiring them in series would product 20.4 no-load Volts. This high voltage reading has the potential of damaging the microchips in the AirWire or Sierra systems, since the locomotive sitting still would draw current only for the sound system.

As mentioned above, the AirWire 900 receiver / DCC Decoder combination circuit board will drive the motor, headlight, and smoke generator, so I didn't need to add any interconnecting wires between the tender and locomotive. I used two of the wires that were already part of the 4-wire Bachmann umbilical cord to feed current from the batteries to the AirWire receiver. The auxiliary DCC output from the AirWire receiver uses the other two wires in this set to power the SoundTraxx Sierra.

As I change batteries in the tender from NiCad to GelCell, I'm going to add a Digitrax decoder so I can use the hand-held controller to trigger the Sierra sound effects instead of relying on their default voltage-controlled settings. With battery power, there is no variance in voltage to the Sierra circuit board. I also eliminated the Sierra's 6 Volt rechargeable battery, since it's only purpose is to keep the sound effects on when the locomotive is sitting still when using track power.

For those of you who are familiar with the EasyDCC wireless controller, the AirWire900 system's controller is exactly the same -- only the internal EPROM is different.

As soon as I have adequate battery power in the Consolidation, I'm going to tackle a Heartland Locomotive Works Doozie Rail Bus. The Radio Shack 9.6 Volt batteries may be strong enough to run it.

[DavidGSmith]

I was at the NMRA convention in Seattle and had the oppurtunity to see a number of garden layouts. Two were using an Australian system RCS. E;Mails to one owner advised using NiCad 14.? volt batteries. They seem to have at least 4 hour run time and some are getting a lot more.
Dave

[cacole]

Addendum: I wound up having to put a 5 Ah Gel-cell battery in a trailing boxcar to power the Consolidation, and used the 1.6 Ah Gel-cell and an additional AirWire 900 receiver / decoder in the Doozie Railbus. One of the Radio Shack 9.6 Volt Ni-Cad batteries is in a caboose to power the marker lights and interior lighting. The Radio Shack batteries and smaller Gel-cell did not have enough power for the Consolidation to make it around the layout more than once without slowing down or completely stalling. With the 5 Ah Gel-cell I can run for several hours without any sign of battery discharge, and the 1.6 Ah Gel-cell provides plenty of power for the Doozie's headlight, motor, lights in both coaches, and tail lights.

[Anonymous]

I WANT ONE... I better get the engine first though[:D]